ENTERICALLY TRANSMITTED NON-A/NON-B HEPATITIS VIRAL AGENT AND CHARACTERISTIC EPITOPES THEREOF

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. Application Serial No.07/505,888, filed April 5, 1990, which is a continuation-in-part of U.S. Application Serial No. 420,921, filed October 13, 1989, which is a continuation-in-part of U.S. Application Serial No. 367,486, filed June 16, 1989, which is a continuation-in-part of U.S. Application Serial No. 336,672, filed April 11, 1989, which is a continuation-in-part of U.S. Application Serial No.

208,997, filed June 17, 1988, all of which are herein incorporated by reference.

INTRODUCTION Field of Invention

This invention relates to recombinant proteins, genes, and gene probes and more specifically to such proteins and probes derived from an enterically transmitted nonA/nonB hepatitis viral agent, to diagnostic methods and vaccine applications which employ the proteins and probes, and to gene segments that encode specific epitopes (and proteins artificially produced to contain those epitopes) that are particularly useful in diagnosis and prophylaxis.

Background

Enterically transmitted non-A/non-B hepatitis viral agent (ET-NANB; also referred to herein as HEV) is the reported cause of hepatitis in several epidemics and sporadic cases in Asia, Africa, Europe, Mexico, and the Indian subcontinent. Infection is usually by water contaminated with feces, although

the virus may also spread by close physical contact. The virus does not seem to cause chronic infection. The viral etiology in ET-NANB has been demonstrated by infection of volunteers with pooled fecal isolates; immune electron microscopy (IEM) studies have shown virus particles with 27-34 nm diameters in stools from infected individuals. The virus particles reacted with antibodies in serum from infected individuals from geographically distinct regions, suggesting that a single viral agent or class is responsible for the majority of ET-NANB hepatitis seen worldwide. No antibody reaction was seen in serum from individuals infected with parenterally transmitted NANB virus (also known as hepatitis C virus or HCV), indicating a different specificity between the two NANB types.

In addition to serological differences, the two types of NANB infection show distinct clinical differences. ET-NANB is characteristically an acute infection, often associated with fever and arthralgia, and with portal inflammation and associated bile stasis in liver biopsy specimens (Arankalle) . Symptoms are usually resolved within six weeks. Parenterally transmitted NANB, by contrast, produces a chronic infection in about 50% of the cases. Fever and arthralgia are rarely seen, and inflammation has a predominantly parenchymal distribution ( huroo, 1980). The course of ET-NANBH is generally uneventful in healthy individuals, and the vast majority of those infected recover without the chronic sequelae seen with HCV. One peculiar epidemiologic feature of this disease, however, is the markedly high mortality observed in pregnant women; this is reported in numerous studies to be on the order of 10-20%. This finding has been seen in a number of epidemiologic studies but at present remains unexplained. Whether this reflects viral pathogenicity, the lethal consequence of the interaction of virus and immune suppressed (pregnant) host, or a reflection of the

debilitated prenatal health of a susceptible malnourished population remains to be clarified.

The two viral agents can also be distin¬ guished on the basis of primate host susceptibility. ET-NANB, but not the parenterally transmitted agent, can be transmitted to cynomolgus monkeys. The parenterally transmitted agent is more readily transmitted to chimpanzees than is ET-NANB (Bradley, 1987) . There have been major efforts worldwide to identify and clone viral genomic sequences associated with ET-NANB hepatitis. One goal of this effort, requiring virus-specific genomic sequences, is to identify and characterize the nature of the virus and its protein products. Another goal is to produce recombinant viral proteins which can be used in antibody-based diagnostic procedures and for a vaccine. Despite these efforts, viral sequences associated with ET-NANB hepatitis have not been successfully identified or cloned heretofore, nor have any virus-specific proteins been identified or produced.

Relevant Literature Arankalle, V.A. , et al., The Lancet, 550

(March 12, 1988) .

Bradley, D.W., et al., J Gen. Virol., 69:1 (1988) .

Bradley, D.W. et al., Proc. Nat. Acad. Sci., USA, 84:6277 (1987).

Gravelle, CR. et al., J. Infect. Diseases, 131:167 (1975).

Kane, M.A. , et al., JAMA, 252:3140 (1984). Khuroo, M.S., Am. J. Med., 48:818 (1980). Khuroo, M.S., et al., Am. J. Med., 68:818

(1983) .

Maniatis, T., et al. Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory (1982) .

Seto, B., et al., Lancet, 11:941 (1984). Sreenivasan, M.A. , et al., J. Gen. Virol.,

65:1005 (1984).

Tabor, E., et al., J. Infect. Dis., 140:789 (1979) .

SUMMARY OF THE INVENTION

Novel compositions, as well as methods of preparation and use of the compositions are provided, where the compositions comprise viral proteins and fragments thereof derived from the viral agent for ET- NANB. A number of specific fragments of viral proteins (and the corresponding genetic sequences) that are particularly useful in diagnosis and vaccine production are also disclosed. Methods for preparation of ET-NANB viral proteins include isolating ET-NANB genomic sequences which are then cloned and expressed in a host cell. The resultant recombinant viral proteins find use as diagnostic agents and as vaccines. The genomic sequences and fragments thereof find use in preparing ET-NANB viral proteins and as probes for virus detection.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows vector constructions and manipulations used in obtaining and sequencing cloned ET-NANB fragment; and

Figures 2A-2B are representations of Southern blots in which a radiolabeled ET-NANB probe was hybridized with amplified cDNA fragments prepared from RNA isolated from infected (I) and non-infected (N) bile sources (2A), and from infected (I) and non- infected (N) stool-sample sources (2B) .

DESCRIPTION OF SPECIFIC EMBODIMENTS Novel compositions comprising generic sequences and fragments thereof derived from the viral agent for ET-NANB are provided, together with recombinant viral proteins produced using the genomic sequences and methods of using these compositions. Epitopes on the viral protein have been identified that are particularly useful in diagnosis and vaccine production. Small peptides containing the epitopes are recognized by multiple sera of patients infected with ET-NANB.

The molecular cloning of HEV was accomp¬ lished by two very different approaches. The first successful identification of a molecular clone was based on the differential hybridization of putative HEV cDNA clones to heterogeneous cDNA from infected and uninfected cyno bile. cDNAs from both sources were labeled to high specific activity with 32P to identify a clone that hybridized specifically to the infected source probe. A cyno monkey infected with the Burma isolate of HEV was used in these first experiments. The sensitivity of this procedure is directly related to the relative abundance of the specific sequence against the overall background. In control experiments, it was found that specific identification of a target sequence may be obtained with as little as 1 specific part per 1000 background sequences. A number of clones were identified by this procedure using libraries and probes made from infected (Burma isolate) and control uninfected cyno bile. The first extensively characterized clone of the 16 plaques purified by this protocol was given the designation ET1.1.

ET1.1 was first characterized as both derived from and unique to the infected source cDNA. Heterogeneous cDNA was amplified from both infected and uninfected sources using a sequence independent single premier amplification technique (SISPA) . This

technique is described in copending application serial No. 208,512, filed June 17, 1988. The limited pool of cDNA made from Burma infected cyno bile could then be amplified enzymatically prior to cloning or hybridization using putative HEV clones as probes. ET1.1 hybridized specifically to the original bile cDNA from the infected source. Further validation of this clone as derived from the genome of HEV was demonstrated by the similarity of the ET1.1 sequence and those present in SISPA cDNA prepared from five different human stool samples collected from different ET-NANBH epidemics including Somalia, Tashkent, Borneo, Mexico and Pakistan. These molecular epidemiologic studies established the isolated sequence as derived from the virus that represented the major cause of ET-NANBH worldwide.

The viral specificity of ET1.1 was further established by the finding that the clone hybridized specifically to RNA extracted from infected cyno liver. Hybridization analysis of polyadenylated RNA demonstrated a unique 7.5 Kb polyadenylated transcript not present in uninfected liver. The size of this transcript suggested that it represented the full length viral genome. Strand specific oligonucleotides were also used to probe viral genomic RNA extracted directly from semi-purified virions prepared from human stool. The strand specificity was based on the RNA-directed RNA polymerase (RDRP) open reading frame (ORF) identified in ET1.1 (see below). Only the probe detecting the sense strand hybridized to the nucleic acid. These studies characterized HEV as a plus sense, single stranded genome. Strand specific hybridization to RNA extracted from the liver also established that the vast majority of intracellular transcript was positive sense. Barring any novel mechanism for virus expression, the negative strand, although not detectable, would be present at a

ratio of less than 1:100 when compared with the sense strand.

ET1.1 was documented as exogenous when tested by both Southern blot hybridization and PCR using genomic DNAs derived from uninfected humans, infected and uninfected cynos and also the genomic DNAs from E_ coli and various bacteriophage sources. The latter were tested in order to rule out trivial contamination with an exogenous sequence introduced during the numerous enzymatic manipulations performed during cDNA construction and amplification. It was also found that the nucleotide sequence of the ET1.1 clone was not homologous to any entries in the Genebank database. The translated open reading frame of the ET1.1 clone did, however, demonstrate limited homology with consensus amino acid residues consistent with an RNA-directed RNA polymerase. This consensus amino acid motif is shared among all positive strand RNA viruses and, as noted above, is present at the 3' end of the HCV genome. The 1.3 Kb clone was therefore presumed to be derived, at least in part, from the nonstructural portion of the viral genome.

Because of the relationship of different strains of ET-NANB to each other that has been demonstrated by the present invention, the genome of the ET-NANB viral agent is defined in this specification as containing a region which is homologous to the 1.33 kb DNA EcoRI insert present in plasmid pTZKFl (ET1.1) carried in E_ _; _ coli strain BB4 and having ATCC deposit no. 67717. The entire sequence, in both directions, has now been identified as set forth below. The sequences of both strands are provided, since both strands can encode proteins. However, the sequence in one direction has been designated as the "forward" sequence because of statistical similarities to known proteins and because the forward sequence is known to be predominately protein-encoding. This sequence is set forth below

along with the three possible translation sequences. There is one long open reading frame that starts at nucleotide 145 with an isoleucine and extends to the end of the sequence. The two other reading frames have many termination codons. Standard abbreviations for nucleotides and amino acids are used here and elsewhere in this specification.

The gene sequence given below is substantially identical to one given in the parent application. The present sequence differs in the omission of the first 37 nucleotides at the 5' end and last 13 nucleotides at the 3' end, which are derived from the linker used for cloning rather than from the virus. In addition, a G was omitted at position 227 of the sequence given in the parent application.

The following gene sequence has SEQ ID N0.1; the first amino acid sequence in reading frame beginning with nucleotide 1 has SEQ ID NO.2; the second amino acid sequence in reading frame beginning with nucleotide 2 has SEQ ID NO.3; and the third amino acid sequence in reading frame beginning with nucleotide 3 has SEQ ID NO.4.

Forward Sequence

SEQ IP NO. 1:

AGACCTGTCC CTGTTGCAGC TGTTCTACCA CCCTGCCCCG AGCTCGAACA GGGCCTTCTC 60

TACCTGCCCC AGGAGCTCAC CACCTGTGAT AGTGTCGTAA CATTTGAATT AACAGACATT 120 GTGCACTGCC GCATGGCCGC CCCGAGCCAG CGCAAGGCCG TGCTGTCCAC ACTCGTGGGC 180

CGCTACGGCG GTCGCACAAA GCTCTACAAT GCTTCCCACT CTGATGTTCG CGACTCTCTC 240

GCCCGTTTTA TCCCGGCCAT TGGCCCCGTA CAGGTTACAA CTTGTGAATT GTACGAGCTA 300

GTGGAGGCCA TGGTCGAGAA GGGCCAGGAT GGCTCCGCCG TCCTTGAGCT TGATCTTTGC 360

AACCGTGACG TGTCCAGGAT CACCTTCTTC CAGAAAGATT GTAACAAGTT CACCACAGGT 420 GAGACCATTG CCCATGGTAA AGTGGGCCAG GGCATCTCGG CCTGGAGCAA GACCTTCTGC 480

GCCCTCTTTG GCCCTTGGTT CCGCGCTATT GAGAAGGCTA TTCTGGCCCT GCTCCCTCAG 540

GGTGTGTTTT ACGGTGATGC CTTTGATGAC ACCGTCTTCT CGGCGGCTGT GGCCGCAGCA 600

AAGGCATCCA TGGTGTTTGA GAATGACTTT TCTGAGTTTG ACTCCACCCA GAATAACTTT 660

TCTCTGGGTC TAGAGTGTGC TATTATGGAG GAGTGTGGGA TGCCGCAGTG GCTCATCCGC 720 CTGTATCACC TTATAAGGTC TGCGTGGATC TTGCAGGCCC CGAAGGAGTC TCTGCGAGGG 780

TTTTGGAAGA AACACTCCGG TGAGCCCGGC ACTCTTCTAT GGAATACTGT CTGGAATATG 840

GCCGTTATTA CCCACTGTTA TGACTTCCGC GATTTTCAGG TGGCTGCCTT TAAAGGTGAT 900

GATTCGATAG TGCTTTGCAG TGAGTATCGT CAGAGTCCAG GAGCTGCTGT CCTGATCGCC 960

GGCTGTGGCT TGAAGTTGAA GGTAGATTTC CGCCCGATCG GTTTGTATGC AGGTGTTGTG 1020 GTGGCCCCCG GCCTTGGCGC GCTCCCTGAT GTTGTGCGCT TCGCCGGCCG GCTTACCGAG 1080

AAGAATTGGG GCCCTGGCCC TGAGCGGGCG GAGCAGCTCC GCCTCGCTGT TAGTGATTTC 1140

CTCCGCAAGC TCACGAATGT AGCTCAGATG TGTGTGGATG TTGTTTCCCG TGTTTATGGG 1200

GTTTCCCCTG GACTCGTTCA TAACCTGATT GGCATGCTAC AGGCTGTTGC TGATGGCAAG 1260

GCACATTTCA CTGAGTCAGT AAAACCAGTG CTCGA 1295 SEQ ID NO. 2:

Arg Pro Val Pro Val Ala Ala Val Leu Pro Pro Cys Pro Glu Leu Glu 1 5 10 15 Gin Gly Leu Leu Tyr Leu Pro Gin Glu Leu Thr Thr Cys Asp Ser Val

20 25 30

Val Thr Phe Glu Leu Thr Asp Ile Val His Cys Arg Met Ala Ala Pro 35 40 45

Ser Gin Arg Lys Ala Val Leu Ser Thr Leu Val Gly Arg Tyr Gly Gly 50 55 60

Arg Thr Lys Leu Tyr Asn Ala Ser His Ser Asp Val Arg Asp Ser Leu 65 70 75 80

Ala Arg Phe Ile Pro Ala Ile Gly Pro Val Gin Val Thr Thr Cys Glu 85 90 95

Leu Tyr Glu Leu Val Glu Ala Met Val Glu Lys Gly Gin Asp Gly Ser 100 105 110

Ala Val Leu Glu Leu Asp Leu Cys Asn Arg Asp Val Ser Arg Ile Thr

115 120 125

Phe Phe Gin Lys Asp Cys Asn Lys Phe Thr Thr Gly Glu Thr He Ala 130 135 140

His Gly Lys Val Gly Gin Gly He Ser Ala Trp Ser Lys Thr Phe Cys 145 150 155 160

Ala Leu Phe Gly Pro Trp Phe Arg Ala Ile Glu Lys Ala He Leu Ala 165 170 175

Leu Leu Pro Gin Gly Val Phe Tyr Gly Asp Ala Phe Asp Asp Thr Val 180 185 190

Phe Ser Ala Ala Val Ala Ala Ala Lys Ala Ser Met Val Phe Glu Asn 195 200 205

Asp Phe Ser Glu Phe Asp Ser Thr Gin Asn Asn Phe Ser Leu Gly Leu 210 215 220

Glu Cys Ala Ile Met Glu Glu Cys Gly Met Pro Gin Trp Leu Ile Arg 225 230 235 240

Leu Tyr His Leu Ile Arg Ser Ala Trp He Leu Gin Ala Pro Lys Glu 245 250 255

Ser Leu Arg Gly Phe Trp Lys Lys His Ser Gly Glu Pro Gly Thr Leu 260 265 270

Leu Trp Asn Thr Val Trp Asn Met Ala Val Ile Thr His Cys Tyr Asp 275 280 285 Phe Arg Asp Phe Gin Val Ala Ala Phe Lys Gly Asp Asp Ser He Val 290 295 300

Leu Cys Ser Glu Tyr Arg Gin Ser Pro Gly Ala Ala Val Leu Ile Ala 305 310 315 320

Gly Cys Gly Leu Lys Leu Lys Val Asp Phe Arg Pro He Gly Leu Tyr 325 330 335

Ala Gly Val Val Val Ala Pro Gly Leu Gly Ala Leu Pro Asp Val Val 340 345 350

Arg Phe Ala Gly Arg Leu Thr Glu Lys Asn Trp Gly Pro Gly Pro Glu 355 360 365 Arg Ala Glu Gin Leu Arg Leu Ala Val Ser Asp Phe Leu Arg Lys Leu 370 375 380

Thr Asn Val Ala Gin Met Cys Val Asp Val Val Ser Arg Val Tyr Gly

385 390 395 400

Val Ser Pro Gly Leu Val His Asn Leu Ile Gly Met Leu Gin Ala Val

405 410 415

Ala Asp Gly Lys Ala His Phe Thr Glu Ser Val Lys Pro Val Leu 420 425 430

SEQ ID NO. 3:

Asp Leu Ser Leu Leu Gin Leu Phe Tyr His Pro Ala Pro Ser Ser Asn 1 5 10 15

Arg Ala Phe Ser Thr Cys Pro Arg Ser Ser Pro Pro Val He Val Ser

20 25 30

. His Leu Asn . Gin Thr Leu Cys Thr Ala Ala Trp Pro Pro Arg 35 40 45

Ala Ser Ala Arg Pro Cys Cys Pro His Ser Trp Ala Ala Thr Ala Val 50 55 60

Ala Gin Ser Ser Thr Met Leu Pro Thr Leu Met Phe Ala Thr Leu Ser 65 70 75 80

Pro Val Leu Ser Arg Pro Leu Ala Pro Tyr Arg Leu Gin Leu Val Asn 85 90 95

Cys Thr Ser . Trp Arg Pro Trp Ser Arg Arg Ala Arg Met Ala Pro 100 105 110

Pro Ser Leu Ser Leu Ile Phe Ala Thr Val Thr Cys Pro Gly Ser Pro 115 120 125

Ser Ser Arg Lys Ile Val Thr Ser Ser Pro Gin Val Arg Pro Leu Pro 130 135 140

Met Val Lys Trp Ala Arg Ala Ser Arg Pro Gly Ala Arg Pro Ser Ala 145 150 155 160

Pro Ser Leu Ala Leu Gly Ser Ala Leu Leu Arg Arg Leu Phe Trp Pro 165 170 175

Cys Ser Leu Arg Val Cys Phe Thr Val Met Pro Leu Met Thr Pro Ser 180 185 190

Ser Arg Arg Leu Trp Pro Gin Gin Arg His Pro Trp Cys Leu Arg Met 195 200 205

Thr Phe Leu Ser Leu Thr Pro Pro Arg Ile Thr Phe Leu Trp Val . 210 215 220 Ser Val Leu Leu Trp Arg Ser Val Gly Cys Arg Ser Gly Ser Ser Ala

225 230 235 240

Cys He Thr Leu . Gly Leu Arg Gly Ser Cys Arg Pro Arg Arg Ser 245 250 255

Leu Cys Glu Gly Phe Gly Arg Asn Thr Pro Val Ser Pro Ala Leu Phe 260 265 270

Tyr Gly lie Leu Ser Gly Ile Trp Pro Leu Leu Pro Thr Val Met Thr 275 280 285

Ser Ala Ile Phe Arg Trp Leu Pro Leu Lys Val Met He Arg . Cys 290 295 300 Phe Ala Val Ser He Val Arg Val Gin Glu Leu Leu Ser . Ser Pro 305 310 315 320

Ala Val Ala . Ser . Arg . He Ser Ala Arg Ser Val Cys Met

325 330 335

Gin Val Leu Trp Trp Pro Pro Ala Leu Ala Arg Ser Leu Met Leu Cys

340 345 350

Ala Ser Pro Ala Gly Leu Pro Arg Arg lie Gly Ala Leu Ala Leu Ser 355 360 365

Gly Arg Ser Ser Ser Ala Ser Leu Leu Val He Ser Ser Ala Ser Ser 370 375 380

Arg Met . Leu Arg Cys Val Trp Met Leu Phe Pro Val Phe Met Gly 385 390 395 400

Phe Pro Leu Asp Ser Phe He Thr Leu Ala Cys Tyr Arg Leu Leu 405 410 415

Leu Met Ala Arg His He Ser Leu Ser Gin . Asn Gin Cys Ser 420 425 430

SEQ ID NO. 4:

Thr Cys Pro Cys Cys Ser Cys Ser Thr Thr Leu Pro Arg Ala Arg Thr 1 5 10 15

Gly Pro Ser Leu Pro Ala Pro Gly Ala His His Leu . . Cys Arg

20 25 30

Asn He . He Asn Arg His Cys Ala Leu Pro His Gly Arg Pro Glu

35 40 45

Pro Ala Gin Gly Arg Ala Val His Thr Arg Gly Pro Leu Arg Arg Ser 50 55 60

His Lys Ala Leu Gin Cys Phe Pro Leu . Cys Ser Arg Leu Ser Arg 65 70 75 80 Pro Phe Tyr Pro Gly His Trp Pro Arg Thr Gly Tyr Asn Leu . He

85 90 95

Val Arg Ala Ser Gly Gly His Gly Arg Glu Gly Pro Gly Trp Leu Arg 100 105 110

Arg Pro . Ala . Ser Leu Gin Pro . Arg Val Gin Asp His Leu 115 120 125

Leu Pro Glu Arg Leu . Gin Val His His Arg . Asp His Cys Pro 130 135 140

Trp . Ser Gly Pro Gly His Leu Gly Leu Glu Gin Asp Leu Leu Arg

145 150 155 160 Pro Leu Trp Pro Leu Val Pro Arg Tyr . Glu Gly Tyr Ser Gly Pro

165 170 175

Ala Pro Ser Gly Cys Val Leu Arg . Cys Leu . . His Arg Leu 180 185 190

Leu Gly Gly Cys Gly Arg Ser Lys Gly He His Gly Val . Glu . 195 200 205

Leu Phe . Val . Leu His Pro Glu . Leu Phe Ser Gly Ser Arg 210 215 220

10

Val Cys Tyr Tyr Gly Gly Val Trp Asp Ala Ala Val Ala His Pro Pro 225 230 235 240

Val Ser Pro Tyr Lys Val Cys Val Asp Leu Ala Gly Pro Glu Gly Val

15 245 250 255

Ser Ala Arg Val Leu Glu Glu Thr Leu Arg Ala Arg His Ser Ser 260 265 270

20 •Met Glu Tyr Cys Leu Glu Tyr Gly Arg Tyr Tyr Pro Leu Leu Leu 275 280 285

Pro Arg Phe Ser Gly Gly Cys Leu . Arg . . Phe Asp Ser Ala 290 295 300

25

Leu Gin . Val Ser Ser Glu Ser Arg Ser Cys Cys Pro Asp Arg Arg 305 310 315 320

Leu Trp Leu Glu Val Glu Gly Arg Phe Pro Pro Asp Arg Phe Val Cys 30 325 330 335

Arg Cys Cys Gly Gly Pro Arg Pro Trp Arg Ala Pro . Cys Cys Ala 340 345 350

35 Leu Arg Arg Pro Ala Tyr Arg Glu Glu Leu Gly Pro Trp Pro . Ala

355 360 365

Gly Gly Ala Ala Pro Pro Arg Cys . . Phe Pro Pro Gin Ala His 370 375 380

40

Glu Cys Ser Ser Asp Val Cys Gly Cys Cys Phe Pro Cys Leu Trp Gly 385 390 395 400

Phe Pro Trp Thr Arg Ser . Pro Asp Trp His Ala Thr Gly Cys Cys 45 405 410 415

. Trp Gin Gly Thr Phe His . Val Ser Lys Thr Ser Ala Arg 420 425 430

>0 The complementary strand, referred to here as the "reverse sequence, " is set forth below in the same manner as the forward sequence set forth above . Several open reading frames , shorter than the long open reading frame found in the forward sequence, can

be seen in this reverse sequence. Because of the relative brevity of the open reading frames in the reverse direction, they are probably not expressed. The following gene sequence has SEQ ID NO.5. Reverse Sequence

SEQ ID NO.5:

TCGAGCACTG GTTTTACTGA CTCAGTGAAA TGTGCCTTGC CATCAGCAAC AGCCTGTAGC 60 ATGCCAATCA GGTTATGAAC GAGTCCAGGG GAAACCCCAT AAACACGGGA AACAACATCC 120

ACACACATCT GAGCTACATT CGTGAGCTTG CGGAGGAAAT CACTAACAGC GAGGCGGAGC 180

TGCTCCGCCC GCTCAGGGCC AGGGCCCCAA TTCTTCTCGG TAAGCCGGCC GGCGAAGCGC 240

ACAACATCAG GGAGCGCGCC AAGGCCGGGG GCCACCACAA CACCTGCATA CAAACCGATC 300

GGGCGGAAAT CTACCTTCAA CTTCAAGCCA CAGCCGGCGA TCAGGACAGC AGCTCCTGGA 360 CTCTGACGAT ACTCACTGCA AAGCACTATC GAATCATCAC CTTTAAAGGC AGCCACCTGA 420

AAATCGCGGA AGTCATAACA GTGGGTAATA ACGGCCATAT TCCAGACAGT ATTCCATAGA 480

AGAGTGCCGG GCTCACCGGA GTGTTTCTTC CAAAACCCTC GCAGAGACTC CTTCGGGGCC 540

TGCAAGATCC ACGCAGACCT TATAAGGTGA TACAGGCGGA TGAGCCACTG CGGCATCCCA 600

CACTCCTCCA TAATAGCACA CTCTAGACCC AGAGAAAAGT TATTCTGGGT GGAGTCAAAC 660 TCAGAAAAGT CATTCTCAAA CACCATGGAT GCCTTTGCTG CGGCCACAGC CGCCGAGAAG 720

ACGGTGTCAT CAAAGGCATC ACCGTAAAAC ACACCCTGAG GGAGCAGGGC CAGAATAGCC 780

TTCTCAATAG CGCGGAACCA AGGGCCAAAG AGGGCGCAGA AGGTCTTGCT CCAGGCCGAG 840

ATGCCCTGGC CCACTTTACC ATGGGCAATG GTCTCACCTG TGGTGAACTT GTTACAATCT 900

TTCTGGAAGA AGGTGATCCT GGACACGTCA CGGTTGCAAA GATCAAGCTC AAGGACGGCG 960 GAGCCATCCT GGCCCTTCTC GACCATGGCC TCCACTAGCT CGTACAATTC ACAAGTTGTA 1020

ACCTGTACGG GGCCAATGGC CGGGATAAAA CGGGCGAGAG AGTCGCGAAC ATCAGAGTGG 1080

GAAGCATTGT AGAGCTTTGT GCGACCGCCG TAGCGGCCCA CGAGTGTGGA CAGCACGGCC 1140

TTGCGCTGGC TCGGGGCGGC CATGCGGCAG TGCACAATGT CTGTTAATTC AAATGTTACG 1200

ACACTATCAC AGGTGGTGAG CTCCTGGGGC AGGTAGAGAA GGCCCTGTTC GAGCTCGGGG 1260 CAGGGTGGTA GAACAGCTGC AACAGGGACA GGTCT 1295

Identity of this sequence with sequences in etiologic agents has been confirmed by locating a

corresponding sequence in a viral strain isolated in Burma. The Burmese isolate contains the following sequence of nucleotides (one strand and open reading frames shown) . The following gene sequence has SEQ ID NO.6; the protein sequence corresponding to 0RF1 has SEQ ID NO.7; ORF2 has SEQ ID NO.8; and ORF3 has SEQ ID NO.9.

SEQUENCE OF HEV (BURMA STRAIN) J -0RF1 — >

M E A H Q F I K A P G AGGCAGACCACATATGTGGTCGATGCCATGGAGGCCCATCAGTTTATTAAGGCTCCTGGC

I T T A I E Q A A L A A A N S A L A N A ATCACTACTGCTATTGAGCAGGCTGCTCTAGCAGCGGCCAACTCTGCCCTGGCGAATGCT 120

V V V R P F L S H Q Q I E I L I N L M Q GTGGTAGTTAGGCCTTTTCTCTCTCACCAGCAGATTGAGATCCTCATTAACCTAATGCAA P R Q L V F R P E V F W N H P I Q R V I

CCTCGCCAGCTTGTTTTCCGCCCCGAGGTTTTCTGGAATCATCCCATCCAGCGTGTC ATC 240

H N E L E L Y C R A R S G R C L E I G A CATAACGAGCTGGAGCTTTACTGCCGCGCCCGCTCCGGCCGCTGTCTTGAAATTGGCGCC

H P R S I N D N P N V V H R C F L R P V CATCCCCGCTCAATAAATGATAATCCTAATGTGGTCCACCGCTGCTTCCTCCGCCCTGTT 360

G R D V Q R W Y T A P T R G P A A N C R GGGCGTGATGTTCAGCGCTGGTATACTGCTCCCACTCGCGGGCCGGCTGCTAATTGCCGG

R S A L R G L P A A D R T Y C L D G F S CGTTCCGCGCTGCGCGGGCTTCCCGCTGCTGACCGCACTTACTGCCTCGACGGGTTTTCT 480 G C N F P A E T G I A L Y S L H D M S P

GGCTGTAACTTTCCCGCCGAGACTGGCATCGCCCTCTACTCCCTTCATGATATGTCA CCA

S D V A E A M F R H G M T R L Y A A L H TCTGATGTCGCCGAGGCCATGTTCCGCCATGGTATGACGCGGCTCTATGCCGCCCTCCAT 600

L P P E V L L P P G T Y R T A S Y L L I CTTCCGCCTGAGGTCCTGCTGCCCCCTGGCACATATCGCACCGCATCGTATTTGCTAATT

H D G R R V V V T Y E G D T S A G Y N H CATGACGGTAGGCGCGTTGTGGTGACGTATGAGGGTGATACTAGTGCTGGTTACAACCAC 720

D V S N L R S W I R T T K V T G D H P L GATGTCTCCAACTTGCGCTCCTGGATTAGAACCACCAAGGTTACCGGAGACCATCCCCTC V I E R V R A I G C H F V L L L T A A P

GTTATCGAGCGGGTTAGGGCCATTGGCTGCCACTπGTTCTCTTGCTCACGGCAGCC CCG 840

E P S P M P Y V P Y P R S T E V Y V R S GAGCCATCACCTATGCCTTATGTTCCTTACCCCCGGTCTACCGAGGTCTATGTCCGATCG

I F G P G G T P S L F P T S C S T K S T ATCTTCGGCCCGGGTGGCACCCCTTCCTTATTCCCAACCTCATGCTCCACTAAGTCGACC 960

F H A V P A H I D R L M L F G A T L D TTCCATGCTGTCCCTGCCCATATTTGGGACCGTCπATGCTGTTCGGGGCCACCTTGGAT

D Q A F C C S R L M T Y L R G I S Y K V GACCAAGCCTTTTGCTGCTCCCGTTTAATGACCTACCTTCGCGGCATTAGCTACAAGGTC 1080 T V G T L V A N E G W N A S E D A L T A

ACTGTTGGTACCCTTGTGGCTAATGAAGGCTGGAATGCCTCTGAGGACGCCCTCACA GCT

V I T A A Y L T I C H Q R Y L R T Q A I GTTATCACTGCCGCCTACCTTACCATTTGCCACCAGCGGTATCTCCGCACCCAGGCTATA 1200

S K G M R R L E R E H A Q K F I T R L Y TCCAAGGGGATGCGTCGTCTGGAACGGGAGCATGCCCAGAAGTTTATAACACGCCTCTAC

S W L F E K S G R D Y I P G R Q L E F Y AGCTGGCTCTTCGAGAAGTCCGGCCGTGATTACATCCCTGGCCGTCAGTTGGAGTTCTAC 1320

A Q C R R W L S A G F H L D P R V L V F GCCCAGTGCAGGCGCTGGCTCTCCGCCGGCTTTCATCTTGATCCACGGGTGTTGGTTTTT D E S A P C H C R T A I R K A L S K F C

GACGAGTCGGCCCCCTGCCATTGTAGGACCGCGATCCGTAAGGCGCTCTCAAAGTTT TGC 1440

C F M K W L G Q E C T C F L Q P A E G A TGCTTCATGAAGTGGCTTGGTCAGGAGTGCACCTGCπCCTTCAGCCTGCAGAAGGCGCC

V G D Q G H D N E A Y E G S D V D P A E GTCGGCGACCAGGGTCATGATAATGAAGCCTATGAGGGGTCCGATGTTGACCCTGCTGAG 1560

S A I S D I S G S Y V V P G T A L Q P L TCCGCCATTAGTGACATATCTGGGTCCTATGTCGTCCCTGGCACTGCCCTCCAACCGCTC

Y Q A L D L P A E I V A R A G R L T A T TACCAGGCCCTCGATCTCCCCGCTGAGATTGTGGCTCGCGCGGGCCGGCTGACCGCCACA 1680 V K V S Q V D G R I D C E T L L G N K T

GTAAAGGTCTCCCAGGTCGATGGGCGGATCGATTGCGAGACCCTTCTTGGTAACAAA ACC

F R T S F V D G A V L E T N G P E R H N TTTCGCACGTCGTTCGTTGACGGGGCGGTCTTAGAGACCAATGGCCCAGAGCGCCACAAT 1800

L S F D A S Q S T M A A G P F S L T Y A CTCTCCTTCGATGCCAGTCAGAGCACTATGGCCGCTGGCCCTTTCAGTCTCACCTATGCC

A S A A G L E V R Y V A A G L D H R A V GCCTCTGCAGCTGGGCTGGAGGTGCGCTATGTTGCTGCCGGGCTTGACCATCGGGCGGTT 1920

F A P G V S P R S A P G E V T A F C S A TTTGCCCCCGGTGTTTCACCCCGGTCAGCCCCCGGCGAGGTTACCGCCTTCTGCTCTGCC L Y R F N R E A Q R H S L I G N L W F H

CTATACAGGTTTAACCGTGAGGCCCAGCGCCATTCGCTGATCGGTAACTTATGGTTC CAT 2040

P E G L I G L F A P F S P G H V W E S A CCTGAGGGACTCATTGGCCTCTTCGCCCCGTTTTCGCCCGGGCATGTTTGGGAGTCGGCT

N P F C G E S T L Y T R T W S E V D A V AATCCATTCTGTGGCGAGAGCACACTTTACACCCGTACTTGGTCGGAGGTTGATGCCGTC 2160

S S P A R P D L G F M S E P S I P S R A TCTAGTCCAGCCCGGCCTGACTTAGGTTTTATGTCTGAGCCTTCTATACCTAGTAGGGCC

A T P T L A A P L P P P A P D P S P P P GCCACGCCTACCCTGGCGGCCCCTCTACCCCCCCCTGCACCGGACCCTTCCCCCCCTCCC 2280 S A P A L A E P A S G A T A G A P A I T

TCTGCCCCGGCGCTTGCTGAGCCGGCTTCTGGCGCTACCGCCGGGGCCCCGGCCATA ACT

H Q T A R H R R L L F T Y P D G S K V F CACCAGACGGCCCGGCACCGCCGCCTGCTCTTCACCTACCCGGATGGCTCTAAGGTATTC 2400

A G S L F E S T C T W L V N A S N V D H GCCGGCTCGCTGTTCGAGTCGACATGCACGTGGCTCGTTAACGCGTCTAATGTTGACCAC

R P G G G L C H A F Y Q R Y P A S F D A CGCCCTGGCGGCGGGCTTTGCCATGCATTTTACCAAAGGTACCCCGCCTCCTTTGATGCT 2520

A S F V M R D G A A A Y T L T P R P I I GCCTCTTTTGTGATGCGCGACGGCGCGGCCGCGTACACACTAACCCCCCGGCCAATAATT H A V A P D Y R L E H N P K R L E A A Y

CACGCTGTCGCCCCTGATTATAGGTTGGAACATAACCCAAAGAGGCTTGAGGCTGCT TAT 2640

R E T C S R L G T A A Y P L L G T G I Y CGGGAAACTTGCTCCCGCCTCGGCACCGCTGCATACCCGCTCCTCGGGACCGGCATATAC

Q V P I G P S F D A W E R N H R P G D E CAGGTGCCGATCGGCCCCAGTTTTGACGCCTGGGAGCGGAACCACCGCCCCGGGGATGAG 2760

L Y L P E L A A R W F E A N R P T R P T TTGTACCTTCCTGAGCTTGCTGCCAGATGGTTTGAGGCCAATAGGCCGACCCGCCCGACT

L T I T E D V A R T A N L A I E L D S A CTCACTATAACTGAGGATGTTGCACGGACAGCGAATCTGGCCATCGAGCTTGACTCAGCC 2880 T D V G R A C A G C R V T P G V V Q Y Q

ACAGATGTCGGCCGGGCCTGTGCCGGCTGTCGGGTCACCCCCGGCGTTGTTCAGTAC CAG

F T A G V P G S G K S R S I T Q A D V D TTTACTGCAGGTGTGCCTGGATCCGGCAAGTCCCGCTCTATCACCCAAGCCGATGTGGAC 3000

V V V V P T R E L R N A W R R R G F A A GTTGTCGTGGTCCCGACGCGTGAGTTGCGTAATGCCTGGCGCCGTCGCGGCTTTGCTGCT

F T P H T A A R V T Q G R R V V I D E A TTTACCCCGCATACTGCCGCCAGAGTCACCCAGGGGCGCCGGGTTGTCATTGATGAGGCT 3120

P S L P P H L L L L H M Q R A A T V H L CCATCCCTCCCCCCTCACCTGCTGCTGCTCCACATGCAGCGGGCCGCCACCGTCCACCTT L G D P N Q I P A I D F E H A G L V P A

CTTGGCGACCCGAACCAGATCCCAGCCATCGACTTTGAGCACGCTGGGCTCGTCCCC GCC 3240

I R P D L G P T S W W H V T H R W P A D ATCAGGCCCGACTTAGGCCCCACCTCCTGGTGGCATGTTACCCATCGCTGGCCTGCGGAT

V C E L I R G A Y P M I Q T T S R V L R GTATGCGAGCTCATCCGTGGTGCATACCCCATGATCCAGACCACTAGCCGGGTTCTCCGT 3360

S L F G E P A V G Q K L V F T Q A A K TCGTTGTTCTGGGGTGAGCCTGCCGTCGGGCAGAAACTAGTGTTCACCCAGGCGGCCAAG

P A N P G S V T V H E A Q G A T Y T E T CCCGCCAACCCCGGCTCAGTGACGGTCCACGAGGCGCAGGGCGCTACCTACACGGAGACC 3480 T I I A T A D A R G L I Q S S R A H A I ACTATTATTGCCACAGCAGATGCCCGGGGCCTTATTCAGTCGTCTCGGGCTCATGCCATT

V A L T R H T E K C V I I D A P G L L R GTTGCTCTGACGCGCCACACTGAGAAGTGCGTCATCATTGACGCACCAGGCCTGCTTCGC 3600

E V G I S D A I V N N F F L A G G E I G GAGGTGGGCATCTCCGATGCAATCGTTAATAACΓΠTTCCTCGCTGGTGGCGAAATTGG T

H Q R P S V I P R G N P D A N V D T L A CACCAGCGCCCATCAGTTATTCCCCGTGGCAACCCTGACGCCAATGTTGACACCCTGGCT 3720

A F P P S C Q I S A F H Q L A E E L G H GCCTTCCCGCCGTCTTGCCAGATTAGTGCCTTCCATCAGTTGGCTGAGGAGCTTGGCCAC R P V P V A A V L P P C P E L E Q G L L

AGACCTGTCCCTGTTGCAGCTGTTCTACCACCCTGCCCCGAGCTCGAACAGGGCCTT CTC 3840

Y L P Q E L T T C D S V V T F E L T D I TACCTGCCCCAGGAGCTCACCACCTGTGATAGTGTCGTAACATTTGAATTAACAGACATT

V H C R M A A P S Q R K A V L S T L V G GTGCACTGCCGCATGGCCGCCCCGAGCCAGCGCAAGGCCGTGCTGTCCACACTCGTGGGC 3960

R Y G G R T K L Y N A S H S D V R D S L CGCTACGGCGGTCGCACAAAGCTCTACAATGCTTCCCACTCTGATGTTCGCGACTCTCTC

A. R F I P A I G P V Q V T T C E L Y E L GCCCGTTTTATCCCGGCCATTGGCCCCGTACAGGTTACAACTTGTGAATTGTACGAGCTA 4080 V E A M V E K G Q D G S A V L E L D L C

GTGGAGGCCATGGTCGAGAAGGGCCAGGATGGCTCCGCCGTCCTTGAGCTTGATCTT TGC

N R D V S R I T F F Q K D C N K F T T G AACCGTGACGTGTCCAGGATCACCTTCTTCCAGAAAGATTGTAACAAGTTCACCACAGGT 4200

E T I A H G K V G Q G I S A W S K T F C GAGACCATTGCCCATGGTAAAGTGGGCCAGGGCATCTCGGCCTGGAGCAAGACCTTCTGC

A L F G P F R A I E K A I L A L L P Q GCCCTCTTTGGCCCTTGGTTCCGCGCTATTGAGAAGGCTATTCTGGCCCTGCTCCCTCAG 4320

G V F Y G D A F D D T V F S A A V A A A GGTGTGTTTTACGGTGATGCCTTTGATGACACCGTCTTCTCGGCGGCTGTGGCCGCAGCA K A S M V F E N D F S E F D S T Q N N F

AAGGCATCCATGGTGTTTGAGAATGACTTTTCTGAGTTTGACTCCACCCAGAATAAC TTT 4440

S L G L E C A I M E E C G M P Q W L I R TCTCTGGGTCTAGAGTGTGCTATTATGGAGGAGTGTGGGATGCCGCAGTGGCTCATCCGC

L Y H L I R S A W I L Q A P K E S L R G CTGTATCACCTTATAAGGTCTGCGTGGATCTTGCAGGCCCCGAAGGAGTCTCTGCGAGGG 4560

F W K K H S G E P G T L L N T V W N M TTTTGGAAGAAACACTCCGGTGAGCCCGGCACTCTTCTATGGAATACTGTCTGGAATATG

A V I T H C Y D F R D F Q V A A F K G D GCCGTTATTACCCACTGTTATGACTTCCGCGATTTTCAGGTGGCTGCCTTTAAAGGTGAT 4680 D S I V L C S E Y R Q S P G A A V L I A

GATTCGATAGTGCTTTGCAGTGAGTATCGTCAGAGTCCAGGAGCTGCTGTCCTGATC GCC

G C G L K L K V D F R P I G L Y A G V V GGCTGTGGCTTGAAGTTGAAGGTAGATTTCCGCCCGATCGGTTTGTATGCAGGTGTTGTG 4800

V A P G L G A L P D V V R F A G R L T E GTGGCCCCCGGCCTTGGCGCGCTCCCTGATGTTGTGCGCTTCGCCGGCCGGCTTACCGAG

K N W G P G P E R A E Q L R L A V S D F AAGAATTGGGGCCCTGGCCCTGAGCGGGCGGAGCAGCTCCGCCTCGCTGTTAGTGATTTC 4920

L R K L T N V A Q M C V D V V S R V Y G CTCCGCAAGCTCACGAATGTAGCTCAGATGTGTGTGGATGTTGTTTCCCGTGTTTATGGG V S P G L V H N L I G M L Q A V A D G K

GTTTCCCCTGGACTCGTTCATAACCTGATTGGCATGCTACAGGCTGTTGCTGATGGC AAG 5040

A H F T E S V K P V L D L T N S I L C R GCACATTTCACTGAGTCAGTAAAACCAGTGCTCGACTTGACAAATTCAATCTTGTGTCGG

I-0RF3— >

M N N M S F A A P M G S R P C A L G

M R P R P V E Z |-0RF2-->

GTGGAATGAATAACATGTCTTTTGCTGCGCCCATGGGTTCGCGACCATGCGCCCTCG GCC 5160

L F C C C S S C F C L C C P R H R P V S I L L L L L M F L P M L P A P P P G Q P

TATTTTGTTGCTGCTCCTCATGTTTTTGCCTATGCTGCCCGCGCCACCGCCCGGTCA GCC

R L A A V V G G A A A V P A V V S G V T S G R R R G R R S G G S G G G F G D R

GTCTGGCCGCCGTCGTGGGCGGCGCAGCGGCGGTTCCGGCGGTGGTTTCTGGGGTGA CCG 5280

G L I L S P S Q S P I F I Q P T P S P P V D S Q P F A I P Y I H P T N P F A P D

GGTTGATTCTCAGCCCTTCGCAATCCCCTATATTCATCCAACCAACCCCTTCGCCCC CGA

M S P L R P G L D L V F A N P P D H S A V T A A A G A G P R V R Q P A R P L G S

TGTCACCGCTGCGGCCGGGGCTGGACCTCGTGTTCGCCAACCCGCCCGACCACTCGG CTC 5400

P L G V T R P S A P P L P H V V D L P Q A W R D Q A Q R P A V A S R R R P T T A

CGCTTGGCGTGACCAGGCCCAGCGCCCCGCCGTTGCCTCACGTCGTAGACCTACCAC AGC

L G P R R Z

G A A P L T A V A P A H D T P P V P D V

TGGGGCCGCGCCGCTAACCGCGGTCGCTCCGGCCCATGACACCCCGCCAGTGCCTGA TGT 5520 D S R G A I L R R Q Y N L S T S P L T S

CGACTCCCGCGGCGCCATCTTGCGCCGGCAGTATAACCTATCAACATCTCCCCTTAC CTC S V A T G T N L V L Y A A P L S P L L P

TTCCGTGGCCACCGGCACTAACCTGGTTCTTTATGCCGCCCCTCTTAGTCCGCTTTT ACC 5640

L Q D G T N T H I M A T E A S N Y A Q Y

CCTTCAGGACGGCACCAATACCCATATAATGGCCACGGAAGCTTCTAATTATGCCCA GTA

R V A R A T I R Y R P L V P N A V G G Y CCGGGTTGCCCGTGCCACAATCCGTTACCGCCCGCTGGTCCCCAATGCTGTCGGCGGTTA 5760

A I S I S F W P Q T T T T P T S V D M N

CGCCATCTCCATCTCATTCTGGCCACAGACCACCACCACCCCGACGTCCGTTGATAT GAA

S I T S T D V R I L V Q P G I A S E L V

TTCAATAACCTCGACGGATGTTCGTATTTTAGTCCAGCCCGGCATAGCCTCTGAGCT TGT 5880 I P S E R L H Y R N Q G W R S V E T S G

GATCCCAAGTGAGCGCCTACACTATCGTAACCAAGGCTGGCGCTCCGTCGAGACCTC TGG

V A E E E A T S G L V M L C I H G S L V

GGTGGCTGAGGAGGAGGCTACCTCTGGTCTTGTTATGCTTTGCATACATGGCTCACT CGT 6000

N S Y T N T P Y T G A L G L L D F A L E AAATTCCTATACTAATACACCCTATACCGGTGCCCTCGGGCTGTTGGACTTTGCCCTTGA

L E F R N L T P G N T N T R V S R Y S S

GCTTGAGTTTCGCAACCTTACCCCCGGTAACACCAATACGCGGGTCTCCCGTTATTC CAG 6120 T A R H R L R R G A D G T A E L T T T A

CACTGCTCGCCACCGCCTTCGTCGCGGTGCGGACGGGACTGCCGAGCTCACCACCAC GGC A T R F M K D L Y F T S T N G V G E I G

TGCTACCCGCTTTATGAAGGACCTCTATTTTACTAGTACTAATGGTGTCGGTGAGAT CGG 6240

R G I A L T L F N L A D T L L G G L P T

CCGCGGGATAGCCCTCACCCTGTTCAACCTTGCTGACACTCTGCTTGGCGGCCTGCC GAC E L I S S A G G Q L F Y S R P V V S A N

AGAATTGATTTCGTCGGCTGGTGGCCAGCTGTTCTACTCCCGTCCCGTTGTCTCAGC CAA 6360 G E P T V K L Y T S V E N A Q Q D K G I

TGGCGAGCCGACTGTTAAGTTGTATACATCTGTAGAGAATGCTCAGCAGGATAAGGG TAT

A I P H D I D L G E S R V V I Q D Y D N TGCAATCCCGCATGACATTGACCTCGGAGAATCTCGTGTGGTTATTCAGGATTATGATAA 6480

Q H E Q D R P T P S P A P S R P F S V L

CCAACATGAACAAGATCGGCCGACGCCTTCTCCAGCCCCATCGCGCCCTTTCTCTGT CCT

R A N D V L L S L T A A E Y D Q S T Y

TCGAGCTAATGATGTGCTTTGGCTCTCTCTCACCGCTGCCGAGTATGACCAGTCCAC TTA 6600 G S S T G P V Y V S D S V T L V N V A T

TGGCTCTTCGACTGGCCCAGTTTATGTTTCTGACTCTGTGACCTTGGTTAATGTTGC GAC

G A Q A V A R S L D W T K V T L D G R P

CGGCGCGCAGGCCGTTGCCCGGTCGCTCGATTGGACCAAGGTCACACTTGACGGTCG CCC 6720

L S T I Q Q Y S K T F F V L P L R G K L CCTCTCCACCATCCAGCAGTACTCGAAGACCTTCTTTGTCCTGCCGCTCCGCGGTAAGCT

S F W E A G T T K A G Y P Y N Y N T T A

CTCTTTCTGGGAGGCAGGCACAACTAAAGCCGGGTACCCTTATAATTATAACACCAC TGC 6840 S D Q L L V E N A A G H R V A I S T Y T

TAGCGACCAACTGCTTGTCGAGAATGCCGCCGGGCACCGGGTCGCTATTTCCACTTA CAC T S L G A G P V S I S A V A V L A P H S

CACTAGCCTGGGTGCTGGTCCCGTCTCCATTTCTGCGGTTGCCGTTTTAGCCCCCCA CTC 6960

A L A L L E D T L D Y P A R A H T F D D

TGCGCTAGCATTGCTTGAGGATACCTTGGACTACCCTGCCCGCGCCCATACTTTTGA TGA

F C P E C R P L G L Q G C A F Q S T V A TTTCTGCCCAGAGTGCCGCCCCCTTGGCCTTCAGGGCTGCGCTTTCCAGTCTACTGTCGC 7080

E L Q R L K M K V G K T R E L Z

TGAGCTTCAGCGCCTTAAGATGAAGGTGGGTAAAACTCGGGAGTTGTAGTTTATTTG CTT

GTGCCCCCCTTCTTTCTGTTGCTTATΓTCTCATTTCTGCGTTCCGCGCTCCCTGA 7195

Total number of bases in this sequence as presented is 7195. The poly-A tail present in the cloned sequence has been omitted.

The ability of the methods described herein to isolate and identify genetic material from other NANB hepatitis strains has been confirmed by identifying genetic material from an isolate obtained in Mexico. The sequence of this isolate was about 75% identical to the ET1.1 sequence set forth in SEQ ID NO.1 above. The sequence was identified by hybridization using the conditions set forth in Section II.B below.

In this different approach to isolation of the virus, cDNA libraries were made directly from a semi- purified human stool specimen collected from an outbreak of ET-NANB in Telixtac. The recovery of cDNA and the construction of representative libraries was assured by the application of sequence independent single premier amplification (SISPA) . A cDNA library constructed in lambda gtll from such an amplified cDNA population was screened with a serum considered to have "high" titer anti-HEV antibodies as assayed by direct immunofluorescence on liver sections from infected cynos . Two cDNA clones, denoted 406.3-2 and 406.4-2, were identified by this approach from a total of 60,000 screened. The sequence of these clones was subsequently localized to the 3 ' half of the viral genome by homology comparison to the HEV (Burma) sequence obtained from clones isolated by hybridization screening of libraries with the original ET1.1 clone.

These isolated cDNA epitopes when used as hybridization probes on Northern blots of RNA extracted from infected cyno liver gave a somewhat different result when compared to the Northern blots obtained with the ET1.1 probe. In addition to the single 7.5 Kb transcript seen using ET1.1, two

additional transcripts of 3 . 7 and 2 . 0 Kb were identified using either of these epitopes as hybridization probes . These polyadenylated transcripts were identified using the extreme 3 ' end epitope clone ( 406 . 3-2 ) as probe and therefore established these transcripts as co-terminal with the 3 ' end of the genome ( see below) . One of the epitope clones ( 406 .4-2 ) was subsequently shown to react in a specific fashion with antisera collected from 5 different geographic epidemics ( Somalia , Burma ,

Mexico , Tashkent and Pakistan ) . The 406 . 3-2 clone reacted with sera from 4 out of these same 5 epidemics (Yarbough et al . , 1990 ) . Both clones reacted with only post inoculation antisera from infected cynos . The latter experiment confirmed that seroconversion in experimentally infected cynos was related to the isolated exogenous cloned sequence .

A composite cDNA sequence ( obtained from several clones of the Mexican strain) is set forth below. Composite Mexico strain sequence ( SEQ ID NO . 10 ) :

SEQ ID NO. 10 :

GCCATGGAGG CCCACCAGTT CATTAAGGCT CCTGGCATCA CTACTGCTAT TGAGCAAGCA 60 GCTCTAGCAG CGGCCAACTC CGCCCTTGCG AATGCTGTGG TGGTCCGGCC TTTCCTTTCC 120

CATCAGCAGG TTGAGATCCT TATAAATCTC ATGCAACCTC GGCAGCTGGT GTTTCGTCCT 180

GAGGTTTTTT GGAATCACCC GATTCAACGT GTTATACATA ATGAGCTTGA GCAGTATTGC 240

CGTGCTCGCT CGGGTCGCTG CCTTGAGATT GGAGCCCACC CACGCTCCAT TAATGATAAT 300

CCTAATGTCC TCCATCGCTG CTTTCTCCAC CCCGTCGGCC GGGATGTTCA GCGCTGGTAC 360 ACAGCCCCGA CTAGGGGACC TGCGGCGAAC TGTCGCCGCT CGGCACTTCG TGGTCTGCCA 420

CCAGCCGACC GCACTTACTG TTTTGATGGC TTTGCCGGCT GCCGTTTTGC CGCCGAGACT 480

GGTGTGGCTC TCTATTCTCT CCATGACTTG CAGCCGGCTG ATGTTGCCGA GGCGATGGCT 540

CGCCACGGCA TGACCCGCCT TTATGCAGCT TTCCACTTGC CTCCAGAGGT GCTCCTGCCT 600

CCTGGCACCT ACCGGACATC ATCCTACTTG CTGATCCACG ATGGTAAGCG CGCGGTTGTC 660 ACTTATGAGG GTGACACTAG CGCCGGTTAC AATCATGATG TTGCCACCCT CCGCACATGG 720

ATCAGGACAA CTAAGGTTGT GGGTGAACAC CCTTTGGTGA TCGAGCGGGT GCGGGGTATT 780

GGCTGTCACT TTGTGTTGTT GATCACTGCG GCCCCTGAGC CCTCCCCGAT GCCCTACGTT 840 CCTTACCCGC GTTCGACGGA GGTCTATGTC CGGTCTATCT TTGGGCCCGG CGGGTCCCCG 900

TCGCTGTTCC CGACCGCTTG TGCTGTCAAG TCCACTTTTC ACGCCGTCCC CACGCACATC 960

TGGGACCGTC TCATGCTCTT TGGGGCCACC CTCGACGACC AGGCCTTTTG CTGCTCCAGG 1020

CTTATGACGT ACCTTCGTGG CATTAGCTAT AAGGTAACTG TGGGTGCCCT GGTCGCTAAT 1080

GAAGGCTGGA ATGCCACCGA GGATGCGCTC ACTGCAGTTA TTACGGCGGC TTACCTCACA 1140 ATATGTCATC AGCGTTATTT GCGGACCCAG GCGATTTCTA AGGGCATGCG CCGGCTTGAG 1200

CTTGAACATG CTCAGAAATT TATTTCACGC CTCTACAGCT GGCTATTTGA GAAGTCAGGT 1260

CGTGATTACA TCCCAGGCCG CCAGCTGCAG TTCTACGCTC AGTGCCGCCG CTGGTTATCT 1320

GCCGGGTTCC ATCTCGACCC CCGCACCTTA GTTTTTGATG AGTCAGTGCC TTGTAGCTGC 1380

CGAACCACCA TCCGGCGGAT CGCTGGAAAA TTTTGCTGTT TTATGAAGTG GCTCGGTCAG 1440 GAGTGTTCTT GTTTCCTCCA GCCCGCCGAG GGGCTGGCGG GCGACCAAGG TCATGACAAT 1500

GAGGCCTATG AAGGCTCTGA TGTTGATACT GCTGAGCCTG CCACCCTAGA CATTACAGGC 1560

TCATACATCG TGGATGGTCG GTCTCTGCAA ACTGTCTATC AAGCTCTCGA CCTGCCAGCT 1620

GACCTGGTAG CTCGCGCAGC CCGACTGTCT GCTACAGTTA CTGTTACTGA AACCTCTGGC 1680

CGTCTGGATT GCCAAACAAT GATCGGCAAT AAGACTTTTC TCACTACCTT TGTTGATGGG 1740 GCACGCCTTG AGGTTAACGG GCCTGAGCAG CTTAACCTCT CTTTTGACAG CCAGCAGTGT 1800

AGTATGGCAG CCGGCCCGTT TTGCCTCACC TATGCTGCCG TAGATGGCGG GCTGGAAGTT 1860

CATTTTTCCA CCGCTGGCCT CGAGAGCCGT GTTGTTTTCC CCCCTGGTAA TGCCCCGACT 1920

GCCCCGCCGA GTGAGGTCAC CGCCTTCTGC TCAGCTCTTT ATAGGCACAA CCGGCAGAGC 1980

CAGCGCCAGT CGGTTATTGG TAGTTTGTGG CTGCACCCTG AAGGTTTGCT CGGCCTGTTC 2040 CCGCCCTTTT CACCCGGGCA TGAGTGGCGG TCTGCTAACC CATTTTGCGG CGAGAGCACG 2100

CTCTACACCC GCACTTGGTC CACAATTACA GACACACCCT TAACTGTCGG GCTAATTTCC 2160

GGTCATTTGG ATGCTGCTCC CCACTCGGGG GGGCCACCTG CTACTGCCAC AGGCCCTGCT 2220

GTAGGCTCGT CTGACTCTCC AGACCCTGAC CCGCTACCTG ATGTTACAGA TGGCTCACGC 2280

CCCTCTGGGG CCCGTCCGGC TGGCCCCAAC CCGAATGGCG TTCCGCAGCG CCGCTTACTA 2340 CACACCTACC CTGACGGCGC TAAGATCTAT GTCGGCTCCA TTTTCGAGTC TGAGTGCACC 2400

TGGCTTGTCA ACGCATCTAA CGCCGGCCAC CGCCCTGGTG GCGGGCTTTG TCATGCTTTT 2460

TTTCAGCGTT ACCCTGATTC GTTTGACGCC ACCAAGTTTG TGATGCGTGA TGGTCTTGCC 2520 GCGTATACCC TTACACCCCG GCCGATCATT CATGCGGTGG CCCCGGACTA TCGATTGGAA 2580

CATAACCCCA AGAGGCTCGA GGCTGCCTAC CGCGAGACTT GCGCCCGCCG AGGCACTGCT 2640

GCCTATCCAC TCTTAGGCGC TGGCATTTAC CAGGTGCCTG TTAGTTTGAG TTTTGATGCC 2700

TGGGAGCGGA ACCACCGCCC GTTTGACGAG CTTTACCTAA CAGAGCTGGC GGCTCGGTGG 2760

TTTGAATCCA ACCGCCCCGG TCAGCCCACG TTGAACATAA CTGAGGATAC CGCCCGTGCG 2820 GCCAACCTGG CCCTGGAGCT TGACTCCGGG AGTGAAGTAG GCCGCGCATG TGCCGGGTGT 2880

AAAGTCGAGC CTGGCGTTGT GCGGTATCAG TTTACAGCCG GTGTCCCCGG CTCTGGCAAG 2940

TCAAAGTCCG TGCAACAGGC GGATGTGGAT GTTGTTGTTG TGCCCACTCG CGAGCTTCGG 3000

AACGCTTGGC GGCGCCGGGG CTTTGCGGCA TTCACTCCGC ACACTGCGGC CCGTGTCACT 3060

AGCGGCCGTA GGGTTGTCAT TGATGAGGCC CCTTCGCTCC CCCCACACTT GCTGCTTTTA 3120 CATATGCAGC GTGCTGCATC TGTGCACCTC CTTGGGGACC CGAATCAGAT CCCCGCCATA 3180

GATTTTGAGC ACACCGGTCT GATTCCAGCA ATACGGCCGG AGTTGGTCCC GACTTCATGG 3240

TGGCATGTCA CCCACCGTTG CCCTGCAGAT GTCTGTGAGT TAGTCCGTGG TGCTTACCCT 3300

AAAATCCAGA CTACAAGTAA GGTGCTCCGT TCCCTTTTCT GGGGAGAGCC AGCTGTCGGC 3360

CAGAAGCTAG TGTTCACACA GGCTGCTAAG GCCGCGCACC CCGGATCTAT AACGGTCCAT 3420 GAGGCCCAGG GTGCCACTTT TACCACTACA ACTATAATTG CAACTGCAGA TGCCCGTGGC 3480

CTCATACAGT CCTCCCGGGC TCACGCTATA GTTGCTCTCA CTAGGCATAC TGAAAAATGT 3540

GTTATACTTG ACTCTCCCGG CCTGTTGCGT GAGGTGGGTA TCTCAGATGC CATTGTTAAT 3600

AATTTCTTCC TTTCGGGTGG CGAGGTTGGT CACCAGAGAC CATCGGTCAT TCCGCGAGGC 3660

AACCCTGACC GCAATGTTGA CGTGCTTGCG GCGTTTCCAC CTTCATGCCA AATAAGCGCC 3720 TTCCATCAGC TTGCTGAGGA GCTGGGCCAC CGGCCGGCGC CGGTGGCGGC TGTGCTACCT 3780

CCCTGCCCTG AGCTTGAGCA GGGCCTTCTC TATCTGCCAC AGGAGCTAGC CTCCTGTGAC 3840

AGTGTTGTGA CATTTGAGCT AACTGACATT GTGCACTGCC GCATGGCGGC CCCTAGCCAA 3900

AGGAAAGCTG TTTTGTCCAC GCTGGTAGGC CGGTATGGCA GACGCACAAG GCTTTATGAT 3960

GCGGGTCACA CCGATGTCCG CGCCTCCCTT GCGCGCTTTA TTCCCACTCT CGGGCGGGTT 4020 ACTGCCACCA CCTGTGAACT CTTTGAGCTT GTAGAGGCGA TGGTGGAGAA GGGCCAAGAC 4080

GGTTCAGCCG TCCTCGAGTT GGATTTGTGC AGCCGAGATG TCTCCCGCAT AACCTTTTTC 4140

CAGAAGGATT GTAACAAGTT CACGACCGGC GAGACAATTG CGCATGGCAA AGTCGGTCAG 4200 GGTATCTTCC GCTGGAGTAA GACGTTTTGT GCCCTGTTTG GCCCCTGGTT CCGTGCGATT 4260

GAGAAGGCTA TTCTATCCCT TTTACCACAA GCTGTGTTCT ACGGGGATGC TTATGACGAC 4320

TCAGTATTCT CTGCTGCCGT GGCTGGCGCC AGCCATGCCA TGGTGTTTGA AAATGATTTT 4380

TCTGAGTTTG ACTCGACTCA GAATAACTTT TCCCTAGGTC TTGAGTGCGC CATTATGGAA 4440

GAGTGTGGTA TGCCCCAGTG GCTTGTCAGG TTGTACCATG CCGTCCGGTC GGCGTGGATC 4500 CTGCAGGCCC CAAAAGAGTC TTTGAGAGGG TTCTGGAAGA AGCATTCTGG TGAGCCGGGC 4560

AGCTTGCTCT GGAATACGGT GTGGAACATG GCAATCATTG CCCATTGCTA TGAGTTCCGG 4620

GACCTCCAGG TTGCCGCCTT CAAGGGCGAC GACTCGGTCG TCCTCTGTAG TGAATACCGC 4680

CAGAGCCCAG GCGCCGGTTC GCTTATAGCA GGCTGTGGTT TGAAGTTGAA GGCTGACTTC 4740

CGGCCGATTG GGCTGTATGC CGGGGTTGTC GTCGCCCCGG GGCTCGGGGC CCTACCCGAT 4800 GTCGTTCGAT TCGCCGGACG GCTTTCGGAG AAGAACTGGG GGCCTGATCC GGAGCGGGCA 4860

GAGCAGCTCC GCCTCGCCGT GCAGGATTTC CTCCGTAGGT TAACGAATGT GGCCCAGATT 4920

TGTGTTGAGG TGGTGTCTAG AGTTTACGGG GTTTCCCCGG GTCTGGTTCA TAACCTGATA 4980

GGCATGCTCC AGACTATTGG TGATGGTAAG GCGCATTTTA CAGAGTCTGT TAAGCCTATA 5040

CTTGACCTTA CACACTCAAT TATGCACCGG TCTGAATGAA TAACATGTGG TTTGCTGCGC 5100 CCATGGGTTC GCCACCATGC GCCCTAGGCC TCTTTTGCTG TTGTTCCTCT TGTTTCTGCC 5160

TATGTTGCCC GCGCCACCGA CCGGTCAGCC GTCTGGCCGC CGTCGTGGGC GGCGCAGCGG 5220

CGGTACCGGC GGTGGTTTCT GGGGTGACCG GGTTGATTCT CAGCCCTTCG CAATCCCCTA 5280

TATTCATCCA ACCAACCCCT TTGCCCCAGA CGTTGCCGCT GCGTCCGGGT CTGGACCTCG 5340

CCTTCGCCAA CCAGCCCGGC CACTTGGCTC CACTTGGCGA GATCAGGCCC AGCGCCCCTC 5400 CGCTGCCTCC CGTCGCCGAC CTGCCACAGC CGGGGCTGCG GCGCTGACGG CTGTGGCGCC 5460

TGCCCATGAC ACCTCACCCG TCCCGGACGT TGATTCTCGC GGTGCAATTC TACGCCGCCA 5520

GTATAATTTG TCTACTTCAC CCCTGACATC CTCTGTGGCC TCTGGCACTA ATTTAGTCCT 5580

GTATGCAGCC CCCCTTAATC CGCCTCTGCC GCTGCAGGAC GGTACTAATA CTCACATTAT 5640

GGCCACAGAG GCCTCCAATT ATGCACAGTA CCGGGTTGCC CGCGCTACTA TCCGTTACCG 5700 GCCCCTAGTG CCTAATGCAG TTGGAGGCTA TGCTATATCC ATTTCTTTCT GGCCTCAAAC 5760

AACCACAACC CCTACATCTG TTGACATGAA TTCCATTACT TCCACTGATG TCAGGATTCT 5820

TGTTCAACCT GGCATAGCAT CTGAATTGGT CATCCCAAGC GAGCGCCTTC ACTACCGCAA 5880 TCAAGGTTGG CGCTCGGTTG AGACATCTGG TGTTGCTGAG GAGGAAGCCA CCTCCGGTCT 5940

TGTCATGTTA TGCATACATG GCTCTCCAGT TAACTCCTAT ACCAATACCC CTTATACCGG 6000

TGCCCTTGGC TTACTGGACT TTGCCTTAGA GCTTGAGTTT CGCAATCTCA CCACCTGTAA 6060

CACCAATACA CGTGTGTCCC GTTACTCCAG CACTGCTCGT CACTCCGCCC GAGGGGCCGA 6120

CGGGACTGCG GAGCTGACCA CAACTGCAGC CACCAGGTTC ATGAAAGATC TCCACTTTAC 6180 CGGCCTTAAT GGGGTAGGTG AAGTCGGCCG CGGGATAGCT CTAACATTAC TTAACCTTGC 6240

TGACACGCTC CTCGGCGGGC TCCCGACAGA ATTAATTTCG TCGGCTGGCG GGCAACTGTT 6300

TTATTCCCGC CCGGTTGTCT CAGCCAATGG CGAGCCAACC GTGAAGCTCT ATACATCAGT 6360

GGAGAATGCT CAGCAGGATA AGGGTGTTGC TATCCCCCAC GATATCGATC TTGGTGATTC 6420

GCGTGTGGTC ATTCAGGATT ATGACAACCA GCATGAGCAG GATCGGCCCA CCCCGTCGCC 6480 TGCGCCATCT CGGCCTTTTT CTGTTCTCCG AGCAAATGAT GTACTTTGGC TGTCCCTCAC 6540

TGCAGCCGAG TATGACCAGT CCACTTACGG GTCGTCAACT GGCCCGGTTT ATATCTCGGA 6600

CAGCGTGACT TTGGTGAATG TTGCGACTGG CGCGCAGGCC GTAGCCCGAT CGCTTGACTG 6660

GTCCAAAGTC ACCCTCGACG GGCGGCCCCT CCCGACTGTT GAGCAATATT CCAAGACATT 6720

CTTTGTGCTC CCCCTTCGTG GCAAGCTCTC CTTTTGGGAG GCCGGCACAA CAAAAGCAGG 6780 TTATCCTTAT AATTATAATA CTACTGCTAG TGACCAGATT CTGATTGAAA ATGCTGCCGG 6840

CCATCGGGTC GCCATTTCAA CCTATACCAC CAGGCTTGGG GCCGGTCCGG TCGCCATTTC 6900

TGCGGCCGCG GTTTTGGCTC CACGCTCCGC CCTGGCTCTG CTGGAGGATA CTTTTGATTA 6960

TCCGGGGCGG GCGCACACAT TTGATGACTT CTGCCCTGAA TGCCGCGCTT TAGGCCTCCA 7020

GGGTTGTGCT TTCCAGTCAA CTGTCGCTGA GCTCCAGCGC CTTAAAGTTA AGGTGGGTAA 7080 AACTCGGGAG TTGTAGTTTA TTTGGCTGTG CCCACCTACT TATATCTGCT GATTTCCTTT 7140

ATTTCCTTTT TCTCGGTCCC GCGCTCCCTG A 7171

The above sequence was obtained from polyadenylated clones. For clarity the 3' polyA "tail" has been omitted.

The sequence above includes a partial cDNA sequence consisting of 1661 nucleotides that was identified in a previous application in this series. The previously identified partial sequence is set forth below, with certain corrections (SEQ ID NO.11). The corrections include deletion of the first 80 bases of the prior reported sequence, which are cloning artifacts; insertion of G after former position 174, of C after 270, and of GGCG after 279; change of C to T at former position 709, of GC to CG at 722-723, of CC to TT at 1238-39, and of C to G at 1606; deletion of T at former position 765; and deletion of the last 11 bases of the former sequence, which are part of a linker sequence and are not of viral origin. Non-A Nσn-B T: Mexican Strain; SEQ ID NO.11 SEQ ID NO. 11:

GTTGCGTGAG GTGGGTATCT CAGATGCCAT TGTTAATAAT TTCTTCCTTT CGGGTGGCGA 60 GGTTGGTCAC CAGAGACCAT CGGTCATTCC GCGAGGCAAC CCTGACCGCA ATGTTGACGT 120

GCTTGCGGCG TTTCCACCTT CATGCCAAAT AAGCGCCTTC CATCAGCTTG CTGAGGAGCT 180

GGGCCACCGG CCGGCGCCGG TGGCGGCTGT GCTACCTCCC TGCCCTGAGC TTGAGCAGGG 240

CCTTCTCTAT CTGCCACAGG AGCTAGCCTC CTGTGACAGT GTTGTGACAT TTGAGCTAAC 300

TGACATTGTG CACTGCCGCA TGGCGGCCCC TAGCCAAAGG AAAGCTGTTT TGTCCACGCT 360 GGTAGGCCGG TATGGCAGAC GCACAAGGCT TTATGATGCG GGTCACACCG ATGTCCGCGC 420

CTCCCTTGCG CGCTTTATTC CCACTCTCGG GCGGGTTACT GCCACCACCT GTGAACTCTT 480

TGAGCTTGTA GAGGCGATGG TGGAGAAGGG CCAAGACGGT TCAGCCGTCC TCGAGTTGGA 540

TTTGTGCAGC CGAGATGTCT CCCGCATAAC CTTTTTCCAG AAGGATTGTA ACAAGTTCAC 600

GACCGGCGAG ACAATTGCGC ATGGCAAAGT CGGTCAGGGT ATCTTCCGCT GGAGTAAGAC 660 CTTTTGTGCC CTGTTTGGCC CCTGGTTCCG TGCGATTGAG AAGGCTATTC TATCCCTTTT 720

ACCACAAGCT GTGTTCTACG GGGATGCTTA TGACGACTCA GTATTCTCTG CTGCCGTGGC 780

TGGCGCCAGC CATGCCATGG TGTTTGAAAA TGATTTTTCT GAGTTTGACT CGACTCAGAA 840

TAACTTTTCC CTAGGTCTTG AGTGCGCCAT TATGGAAGAG TGTGGTATGC CCCAGTGGCT 900

TGTCAGGTTG TACCATGCCG TCCGGTCGGC GTGGATCCTG CAGGCCCCAA AAGAGTCTTT 960

GAGAGGGTTC TGGAAGAAGC ATTCTGGTGA GCCGGGCACG TTGCTCTGGA ATACGGTGTG 1020

GAACATGGCA ATCATTGCCC ATTGCTATGA GTTCCGGGAC CTCCAGGTTG CCGCCTTCAA 1080 GGGCGACGAC TCGGTCGTCC TCTGTAGTGA ATACCGCCAG AGCCCAGGCG CCGGTTCGCT 1140

TATAGCAGGC TGTGGTTTGA AGTTGAAGGC TGACTTCCGG CCGATTGGGC TGTATGCCGG 1200

GGTTGTCGTC GCCCCGGGGC TCGGGGCCCT ACCCGATGTC GTTCGATTCG CCGGACGGCT 1260

TTCGGAGAAG AACTGGGGGC CTGATCCGGA GCGGGCAGAG CAGCTCCGCC TCGCCGTGCA 1320

GGATTTCCTC CGTAGGTTAA CGAATGTGGC CCAGATTTGT GTTGAGGTGG TGTCTAGAGT 1380 TTACGGGGTT TCCCCGGGTC TGGTTCATAA CCTGATAGGC ATGCTCCAGA CTATTGGTGA 1440

TGGTAAGGCG CATTTTACAG AGTCTGTTAA GCCTATACTT GACCTTACAC ACTCAATTAT 1500

GCACCGGTCT GAATGAATAA CATGTGGTTT GCTGCGCCCA TGGGTTCGCC ACCATGCGCC 1560

CTAGGCCTCT TTTGC 1575

When comparing the Burmese and Mexican strains, 75.7% identity is seen in a 7189 nucleotide overlap beginning at nucleotide 1 of the Mexican strain and nucleotide 25 of the Burmese strain.

In the same manner, a different strain of HEV was identified in an isolate obtained in Tashkent, U.S.S.R. The Tashkent sequence is given below (SEQ ID NO.12) :

SEQ ID NO. 12:

CGGGCCCCGT ACAGGTCACA ACCTGTGAGT TGTACGAGCT AGTGGAGGCC ATGGTCGAGA 60

AAGGCCAGGA TGGCTCCGCC GTCCTTGAGC TCGATCTCTG CAACCGTGAC GTGTCCAGGA 120

TCACCTTTTT CCAGAAAGAT TGCAATAAGT TCACCACGGG AGAGACCATC GCCCATGGTA 180 AAGTGGGCCA GGGCATTTCG GCCTGGAGTA AGACCTTCTG TGCCCTTTTC GGCCCCTGGT 240

TCCGTGCTAT TGAGAAGGCT ATTCTGGCCC TGCTCCCTCA GGGTGTGTTT TATGGGGATG 300

CCTTTGATGA CACCGTCTTC TCGGCGCGTG TGGCCGCAGC AAAGGCGTCC ATGGTGTTTG 360

AGAATGACTT TTCTGAGTTT GACTCCACCC AGAATAATTT TTCCCTGGGC CTAGAGTGTG 420

CTATTATGGA GAAGTGTGGG ATGCCGAAGT GGCTCATCCG CTTGTACCAC CTTATAAGGT 480 CTGCGTGGAT CCTGCAGGCC CCGAAGGAGT CCCTGCGAGG GTGTTGGAAG AAACACTCCG 540

GTGAGCCCGG CACTCTTCTA TGGAATACTG TCTGGAACAT GGCCGTTATC ACCCATTGTT 600

ACGATTTCCG CGATTTGCAG GTGGCTGCCT TTAAAGGTGA TGATTCGATA GTGCTTTGCA 660

GTGAGTACCG TCAGAGTCCA GGGGCTGCTG TCCTGATTGC TGGCTGTGGC TTAAAGCTGA 720

AGGTGGGTTT CCGTCCGATT GGTTTGTATG CAGGTGTTGT GGTGACCCCC GGCCTTGGCG 780

CGCTTCCCGA CGTCGTGCGC TTGTCCGGCC GGCTTACTGA GAAGAATTGG GGCCCTGGCC 840

CTGAGCGGGC GGAGCAGCTC CGCCTTGCTG TGCG 874

As shown in the following comparison of sequences, the Tashkent (Tash. ) sequence more closely resembles the Burma sequence than the Mexico sequence, as would be expected of two strains from more closely related geographical areas . The numbering system used in the comparison is based on the Burma sequence. As indicated previously, Burma has SEQ ID NO: 6; Mexico, SEQ ID NO: 10; and Tashkent, SEQ ID NO: 12. The letters present in the lines between the sequences indicate conserved nucleotides.

lOv 20v 30v 40v 50v 60v -BURMA AGGCAGACCACATATGTGGTCGATGCCATGGAGGCCCATCAGTTTATTAAGGCTCCTGGC A

GCCATGGAGGCCCA CAGTT ATTAAGGCTCCTGGCA -MEXICO GCCATGGAGGCCCACCAGTTCATTAAGGCTCCTGGCA

70v 80v 90v lOOv HOv 120v -BURMA TCACTACTGCTATTGAGCAGGCTGCTCTAGCAGCGGCCAACTCTGCCCTGGCGAATGCTG TCACTACTGCTATTGAGCA GC GCTCTAGCAGCGGCCAACTC GCCCT GCGAATGCTG -MEXICO TCACTACTGCTATTGAGCAAGCAGCTCTAGCAGCGGCCAACTCCGCCCTTGCGAATGCTG

130v 140v 150v 160v 170v 180v -BURMA TGGTAGTTAGGCCTTTTCTCTCTCACCAGCAGATTGAGATCCTCATTAACCTAATGCAAC TGGT GT GGCCTTT CT TC CA CAGCAG TTGAGATCCT AT AA CT ATGCAAC -MEXICO TGGTGGTCCGGCCTTTCCTTTCCCATCAGCAGGTTGAGATCCTTATAAATCTCATGCAAC

190v 200v 210v 220v 230v 240v -BURMA CTCGCCAGCTTGTTTTCCGCCCCGAGGTTTTCTGGAATCATCCCATCCAGCGTGTCATCC CTCG CAGCT GT TT CG CC GAGGTTTT TGGAATCA CC AT CA CGTGT AT C -MEXICO CTCGGCAGCTGGTGTTTCGTCCTGAGGTTTTTTGGAATCACCCGATTCAACGTGTTATAC

250v 260v 270v 280v 290v 300v -BURMA ATAACGAGCTGGAGCTTTACTGCCGCGCCCGCTCCGGCCGCTGTCTTGAAATTGGCGCCC ATAA GAGCT GAGC TA TGCCG GC CGCTC GG CGCTG CTTGA ATTGG GCCC -MEXICO ATAATGAGCTTGAGCAGTATTGCCGTGCTCGCTCGGGTCGCTGCCTTGAGATTGGAGCCC

310v 320v 330v 340v 350v 360v -BURMA ATCCCCGCTCAATAAATGATAATCCTAATGTGGTCCACCGCTGCTTCCTCCGCCCTGTTG A CC CGCTC AT AATGATAATCCTAATGT TCCA CGCTGCTT CTCC CCC GT G -MEXICO ACCCACGCTCCATTAATGATAATCCTAATGTCCTCCATCGCTGCTTTCTCCACCCCGTCG

370v 380v 390v 400v 410v 420v -BURMA GGCGTGATGTTCAGCGCTGGTATACTGCTCCCACTCGCGGGCCGGCTGCTAATTGCCGGC G CG GATGTTCAGCGCTGGTA AC GC CC ACT G GG CC GC GC AA TG CG C -MEXICO GCCGGGATGTTCAGCGCTGGTACACAGCCCCGACTAGGGGACCTGCGGCGAACTGTCGCC

430v 440v 450v 460v 470v 480v -BURMA GTTCCGCGCTGCGCGGGCTTCCCGCTGCTGACCGCACTTACTGCCTCGACGGGTTTTCTG G TC GC CT CG GG CT CC C GC GACCGCACTTACTG T GA GG TTT C G -MEXICO GCTCGGCACTTCGTGGTCTGCCACCAGCCGACCGCACTTACTGTTTTGATGGCTTTGCCG

490v 500v 510v 520v 530v 540v -BURMA GCTGTAACTTTCCCGCCGAGACTGGCATCGCCCTCTACTCCCTTCATGATATGTCACCAT

GCTG TTT CCGCCGAGACTGG T GC CTCTA TC CT CATGA TG CC -MEXICO GCTGCCGTTTTGCCGCCGAGACTGGTGTGGCTCTCTATTCTCTCCATGACTTGCAGCCGG

550v 560v 570v 580v 590v 600v -BURMA CTGATGTCGCCGAGGCCATGTTCCGCCATGGTATGACGCGGCTCTATGCCGCCCTCCATC

CTGATGT GCCGAGGC ATG CGCCA GG ATGAC CG CT TATGC GC TCCA -MEXICO CTGATGTTGCCGAGGCGATGGCTCGCCACGGCATGACCCGCCTTTATGCAGCTTTCCACT

610v 620v 630v 640v 650v 660v -BURMA TTCCGCCTGAGGTCCTGCTGCCCCCTGGCACATATCGCACCGCATCGTATTTGCTAATTC T CC CC GAGGT CT CTGCC CCTGGCAC TA CG AC CATC TA TTGCT AT C -MEXICO TGCCTCCAGAGGTGCTCCTGCCTCCTGGCACCTACCGGACATCATCCTACTTGCTGATCC

670v 680v 690v 700v 710v 720v -BURMA ATGACGGTAGGCGCGTTGTGGTGACGTATGAGGGTGATACTAGTGCTGGTTACAACCACG A GA GGTA GCGCG GT GT AC TATGAGGGTGA ACTAG GC GGTTACAA CA G -MEXICO ACGATGGTAAGCGCGCGGTTGTCACTTATGAGGGTGACACTAGCGCCGGTTACAATCATG

730v 740v 750v 760v 770v 780v -BURMA ATGTCTCCAACTTGCGCTCCTGGATTAGAACCACCAAGGTTACCGGAGACCATCCCCTCG ATGT CCA C T CGC C TGGAT AG AC AC AAGGTT GG GA CA CC T G -MEXICO ATGTTGCCACCCTCCGCACATGGATCAGGACAACTAAGGTTGTGGGTGAACACCCTTTGG

790v 800v 810v 820v 830v 840v -BURMA TTATCGAGCGGGTTAGGGCCATTGGCTGCCACTTTGTTCTCTTGCTCACGGCAGCCCCGG T ATCGAGCGGGT GGG ATTGGCTG CACTTTGT T TTG TCAC GC GCCCC G -MEXICO TGATCGAGCGGGTGCGGGGTATTGGCTGTCACTTTGTGTTGTTGATCACTGCGGCCCCTG

850v 860v 870v 880v 890v 900v -BURMA AGCCATCACCTATGCCTTATGTTCCTTACCCCCGGTCTACCGAGGTCTATGTCCGATCGA AGCC TC CC ATGCC TA GTTCCTTACCC CG TC AC GAGGTCTATGTCCG TC A -MEXICO AGCCCTCCCCGATGCCCTACGTTCCTTACCCGCGTTCGACGGAGGTCTATGTCCGGTCTA

910v 920v 930v 940v 950v 960v -BURMA TCTTCGGCCCGGGTGGCACCCCTTCCTTATTCCCAACCTCATGCTCCACTAAGTCGACCT TCTT GG CC GG GG CCCC TC T TTCCC ACC C TG C AAGTC AC T -MEXICO TCTTTGGGCCCGGCGGGTCCCCGTCGCTGTTCCCGACCGCTTGTGCTGTCAAGTCCACTT

970v 980v 990v lOOOv lOlOv 1020v -BURMA TCCATGCTGTCCCTGCCCATATTTGGGACCGTCTTATGCTGTTCGGGGCCACCTTGGATG T CA GC GTCCC C CA AT TGGGACCGTCT ATGCT TT GGGGCCACC T GA G -MEXICO TTCACGCCGTCCCCACGCACATCTGGGACCGTCTCATGCTCTTTGGGGCCACCCTCGACG

1030v 1040v 1050v 1060v 1070v 1080v -BURMA ACCAAGCCTπTGCTGCTCCCGTTTAATGACCTACCTTCGCGGCATTAGCTACAAGGTCA ACCA GCCTTTTGCTGCTCC G T ATGAC TACCTTCG GGCATTAGCTA AAGGT A -MEXICO ACCAGGCCTTTTGCTGCTCCAGGCTTATGACGTACCTTCGTGGCATTAGCTATAAGGTAA

1090v HOOv lllOv 1120v 1130v 1140v -BURMA CTGTTGGTACCCTTGTGGCTAATGAAGGCTGGAATGCCTCTGAGGACGCCCTCACAGCTG CTGT GGT CCCT GT GCTAATGAAGGCTGGAATGCC C GAGGA GC CTCAC GC G -MEXICO CTGTGGGTGCCCTGGTCGCTAATGAAGGCTGGAATGCCACCGAGGATGCGCTCACTGCAG

1150v llδOv 1170v 1180v 1190v 1200v -BURMA TTATCACTGCCGCCTACCTTACCATTTGCCACCAGCGGTATCTCCGCACCCAGGCTATAT TTAT AC GC GC TACCT AC AT TG CA CAGCG TAT T CG ACCCAGGC AT T -MEXICO TTATTACGGCGGCTTACCTCACAATATGTCATCAGCGTTATTTGCGGACCCAGGCGATTT

1210v 1220v 1230v 1240v 1250v 1260v -BURMA CCAAGGGGATGCGTCGTCTGGAACGGGAGCATGCCCAGAAGTTTATAACACGCCTCTACA C AAGGG ATGCG CG CT GA C GA CATGC CAGAA TTTAT CACGCCTCTACA -MEXICO CTAAGGGCATGCGCCGGCTTGAGCTTGAACATGCTCAGAAATTTATTTCACGCCTCTACA

1270v 1280v 1290v 1300v 1310v 1320v -BURMA GCTGGCTCTTCGAGAAGTCCGGCCGTGATTACATCCCTGGCCGTCAGTTGGAGTTCTACG GCTGGCT TT GAGAAGTC GG CGTGATTACATCCC GGCCG CAG TG AGTTCTACG -MEXICO GCTGGCTATTTGAGAAGTCAGGTCGTGATTACATCCCAGGCCGCCAGCTGCAGTTCTACG

1330v 1340v 1350v 1360v 1370v 1380v -BURMA CCCAGTGCAGGCGCTGGCTCTCCGCCGGCTTTCATCTTGATCCACGGGTGTTGGTTTTTG C CAGTGC G CGCTGG T TC GCCGG TT CATCT GA CC CG TT GTTTTTG -MEXICO CTCAGTGCCGCCGCTGGTTATCTGCCGGGπCCATCTCGACCCCCGCACCTTAGTTTTTG

1390v 1400v 1410v 1420v 1430v 1440v -BURMA ACGAGTCGGCCCCCTGCCATTGTAGGACCGCGATCCGTAAGGCGCTCTCAAAGTTTTGCT A GAGTC G CC TG TG G ACC C ATCCG G AAA TTTTGCT -MEXICO ATGAGTCAGTGCCTTGTAGCTGCCGAACCACCATCCGGCGGATCGCTGGAAAATTTTGCT

1450v 1460v 1470v 1480v 1490v 1500v -BURMA GCTTCATGAAGTGGCHGGTCAGGAGTGCACCTGCTTCCTTCAGCCTGCAGAAGGCGCCG G TT ATGAAGTGGCT GGTCAGGAGTG C TG TTCCT CAGCC GC GA GG G -MEXICO GTTTTATGAAGTGGCTCGGTCAGGAGTGTTCTTGTTTCCTCCAGCCCGCCGAGGGGCTGG

1510v 1520v 1530v 1540v 1550v 1560v -BURMA TCGGCGACCAGGGTCATGATAATGAAGCCTATGAGGGGTCCGATGTTGACCCTGCTGAGT

GGCGACCA GGTCATGA AATGA GCCTATGA GG TC GATGTTGA CTGCTGAG -MEXICO CGGGCGACCAAGGTCATGACAATGAGGCCTATGAAGGCTCTGATGTTGATACTGCTGAGC

1570v 1580v 1590v 1600v 1610v 1620v -BURMA CCGCCATTAGTGACATATCTGGGTCCTATGTCGTCCCTGGCACTGCCCTCCAACCGCTCT C GCCA GACAT C GG TC TA TCGT TGG C CT CAA C TCT -MEXICO CTGCCACCCTAGACATTACAGGCTCATACATCGTGGATGGTCGGTCTCTGCAAACTGTCT

1630v 1640v 1650v 1660v 1670v 1680v -BURMA ACCAGGCCCTCGATCTCCCCGCTGAGATTGTGGCTCGCGCGGGCCGGCTGACCGCCACAG A CA GC CTCGA CT CC GCTGA T GT GCTCGCGC G CCG CTG C GC ACAG -MEXICO ATCAAGCTCTCGACCTGCCAGCTGACCTGGTAGCTCGCGCAGCCCGACTGTCTGCTACAG

1690v 1700v 1710v 1720v 1730v 1740v -BURMA TAAAGGTCTCCCAGGTCGATGGGCGGATCGATTGCGAGACCCTTCTTGGTAACAAAACCT T A GT C A C TGG CG T GATTGC A AC T T GG AA AA AC T -MEXICO TTACTGTTACTGAAACCTCTGGCCGTCTGGATTGCCAAACAATGATCGGCAATAAGACTT

1750v 1760v 1770v 1780v 1790v 1800v -BURMA TTCGCACGTCGTTCGTTGACGGGGCGGTCTTAGAGACCAATGGCCCAGAGCGCCACAATC TTC CAC C TT GTTGA GGGGC C T GAG AA GG CC GAGC C AA C -MEXICO TTCTCACTACCTTTGTTGATGGGGCACGCCTTGAGGTTAACGGGCCTGAGCAGCTTAACC

1810V 1820v 1830v 1840v 1850v 1860v -BURMA TCTCCTTCGATGCCAGTCAGAGCACTATGGCCGCTGGCCCTTTCAGTCTCACCTATGCCG TCTC TT GA C CAG G A TATGGC GC GGCCC TT G CTCACCTATGC G -MEXICO TCTCTTTTGACAGCCAGCAGTGTAGTATGGCAGCCGGCCCGTTTTGCCTCACCTATGCTG

1870v 1880v 1890v 1900v 1910v 1920v -BURMA CCTCTGCAGCTGGGCTGGAGGTGCGCTATGTTGCTGCCGGGCTTGACCATCGGGCGGTTT CC G G GGGCTGGA GT C T T C GC GG CT GA CG G GTTT -MEXICO CCGTAGATGGCGGGCTGGAAGTTCATTTTTCCACCGCTGGCCTCGAGAGCCGTGTTGTTT

1930v 1940v 1950v 1960v 1970v 1980v -BURMA TTGCCCCCGGTGTTTCACCCCGGTCAGCCCCCGGCGAGGTTACCGCCTTCTGCTCTGCCC T CCCC GGT T C CC C C CC G GAGGT ACCGCCTTCTGCTC GC C -MEXICO TCCCCCCTGGTAATGCCCCGACTGCCCCGCCGAGTGAGGTCACCGCCTTCTGCTCAGCTC

1990v 2000v 2010v 2020v 2030v 2040v -BURMA TATACAGGTTTAACCGTGAGGCCCAGCGCCATTCGCTGATCGGTAACTTATGGTTCCATC T TA AGG AACCG AG CCAGCGCCA TCG T AT GGTA TT TGG T CA C -MEXICO TTTATAGGCACAACCGGCAGAGCCAGCGCCAGTCGGTTATTGGTAGTTTGTGGCTGCACC

2050v 2060v 2070v 2080v 2090v 2100v -BURMA CTGAGGGACTCATTGGCCTCTTCGCCCCGTTTTCGCCCGGGCATGTTTGGGAGTCGGCTA CTGA GG T T GGCCT TTC C CC TTTTC CCCGGGCATG TGG GTC GCTA -MEXICO CTGAAGGTTTGCTCGGCCTGTTCCCGCCCTTTTCACCCGGGCATGAGTGGCGGTCTGCTA

2110v 2120v 2130v 2140v 2150v 2160v -BURMA ATCCATTCTGTGGCGAGAGCACACTTTACACCCGTACTTGGTCGGAGGTTGATGCCGTCT

A CCATT TG GGCGAGAGCAC CT TACACCCG ACTTGGTC TT G C -MEXICO ACCCATTTTGCGGCGAGAGCACGCTCTACACCCGCACTTGGTCCACAATTACAGACACAC

2170v 2180v 2190v 2200v 2210v 2220v -BURMA CTAGTCCAGCCCGGCCTGACTTAGGTTTTATGTCTGAGCCTTCTATACCTAGTAGGGCCG

C C G C GGC T GGT T TG TG CT C C G GG C -MEXICO CCTTAACTGTCGGGCTAATTTCCGGTCATTTGGATGCTGCTCCCCACTCGGGGGGGCCAC

2230v 2240v 2250v 2260v 2270v 2280v -BURMA CCACGCCTACCCTGGCGGCCCCTCTACCCCCCCCTGCACCGGACCCTTCCCCCCCTCCCT

C C CT CC G C CT TA C C CTG C C CCC C -MEXICO CTGCTACTGCCACAGGCCCTGCTGTAGGCTCGTCTGACTCTCCAGACCCTGACCCGCTAC

2290v 2300v 2310v 2320v 2330v 2340v -BURMA CTGCCCCGGCGCTTGCTGAGCCGGCTTCTGGCGCTACCGCCGGGGCCCCGGCCATAACTC CTG C TG C C TCTGG GC C G G CCC C A T -MEXICO CTGATGTTACAGATGGCTCACGCCCCTCTGGGGCCCGTCCGGCTGGCCCCAACCCGAATG

2350v 2360v 2370V 2380v 2390v 2400v

-BURMA ACCAGACGGCCCGGCACCGCCGCCTGCTCTTCACCTACCCGGATGGCTCTAAGGTATTCG

C CG CGCCGC T CT CACCTACCC GA GGC CTAAG T T G

-MEXICO GCGTTCCGCAG CGCCGCTTACTACACACCTACCCTGACGGCGCTAAGATCTATG

2410v 2420v 2430v 2440v 2450v 2460v -BURMA CCGGCTCGCTGTTCGAGTCGACATGCACGTGGCTCGTTAACGCGTCTAATGTTGACCACC CGGCTC T TTCGAGTC TGCAC TGGCT GT AACGC TCTAA G G CCACC -MEXICO TCGGCTCCATTTTCGAGTCTGAGTGCACCTGGCTTGTCAACGCATCTAACGCCGGCCACC

2470v 2480v 2490v 2500v 2510v 2520v -BURMA GCCCTGGCGGCGGGCTTTGCCATGCATTTTACCAAAGGTACCCCGCCTCCTTTGATGCTG

GCCCTGG GGCGGGCTTTG CATGC TTTT CA G TACCC G TC TTTGA GC -MEXICO GCCCTGGTGGCGGGCTTTGTCATGCTTTTnTCAGCGTTACCCTGATTCGrrTGACGCCA

2530v 2540v 2550v 2560v 2570v 2580v -BURMA CCTCTTTTGTGATGCGCGACGGCGCGGCCGCGTACACACTAACCCCCCGGCCAATAATTC CC TTTGTGATGCG GA GG GCCGCGTA AC CT AC CCCCGGCC AT ATTC -MEXICO CCAAGTTTGTGATGCGTGATGGTCTTGCCGCGTATACCCTTACACCCCGGCCGATCATTC

2590v 2600v 2610v 2620v 2630v 2640v -BURMA ACGCTGTCGCCCCTGATTATAGGTTGGAACATAACCCAAAGAGGCTTGAGGCTGCTTATC A GC GT GCCCC GA TAT G TTGGAACATAACCC AAGAGGCT GAGGCTGC TA C -MEXICO ATGCGGTGGCCCCGGACTATCGATTGGAACATAACCCCAAGAGGCTCGAGGCTGCCTACC

2650v 2660v 2670v 2680v 2690v 2700v -BURMA GGGAAACTTGCTCCCGCCTCGGCACCGCTGCATACCCGCTCCTCGGGACCGGCATATACC G GA ACTTGC CCCGCC GGCAC GCTGC TA CC CTC T GG C GGCAT TACC -MEXICO GCGAGACTTGCGCCCGCCGAGGCACTGCTGCCTATCCACTCTTAGGCGCTGGCATTTACC

2710v 2720v 2730v 2740v 2750v 2760v -BURMA AGGTGCCGATCGGCCCCAGTTTTGACGCCTGGGAGCGGAACCACCGCCCCGGGGATGAGT AGGTGCC T G AGTTTTGA GCCTGGGAGCGGAACCACCGCCC GA GAG -MEXICO AGGTGCCTGTTAGTTTGAGTTTTGATGCCTGGGAGCGGAACCACCGCCCGTTTGACGAGC

2770v 2780v 2790v 2800v 2810v 2820v -BURMA TGTACCTTCCTGAGCTTGCTGCCAGATGGTTTGAGGCCAATAGGCCGACCCGCCCGACTC

T TACCT C GAGCT GC GC G TGGTTTGA CCAA G CC C CC AC -MEXICO TTTACCTAACAGAGCTGGCGGCTCGGTGGHTGAATCCAACCGCCCCGGTCAGCCCACGT

2830v 2840v 2850v 2860v 2870v 2880v -BURMA TCACTATAACTGAGGATGTTGCACGGACAGCGAATCTGGCCATCGAGCTTGACTCAGCCA T A ATAACTGAGGAT GC CG C GC AA CTGGCC T GAGCTTGACTC G A -MEXICO TGAACATAACTGAGGATACCGCCCGTGCGGCCAACCTGGCCCTGGAGCTTGACTCCGGGA

2890v 2900v 2910v 2920v 2930v 2940v -BURMA CAGATGTCGGCCGGGCCTGTGCCGGCTGTCGGGTCACCCCCGGCGπGπCAGTACCAGT GA GT GGCCG GC TGTGCCGG TGT GTC CC GGCGTTGT C GTA CAGT -MEXICO GTGAAGTAGGCCGCGCATGTGCCGGGTGTAAAGTCGAGCCTGGCGTTGTGCGGTATCAGT

2950v 2960v 2970v 2980v 2990v 3000v -BURMA TTACTGCAGGTGTGCCTGGATCCGGCAAGTCCCGCTCTATCACCCAAGCCGATGTGGACG TTAC GC GGTGT CC GG TC GGCAAGTC TC T CA GC GATGTGGA G -MEXICO TTACAGCCGGTGTCCCCGGCTCTGGCAAGTCAAAGTCCGTGCAACAGGCGGATGTGGATG

3010v 3020V 3030v 3040v 3050v 3060v

-BURMA TTGTCGTGGTCCCGACGCGTGAGTTGCGTAATGCCTGGCGCCGTCGCGGCTTTGCTGCTT

TTGT GT GT CC AC CG GAG T CG AA GC TGGCG CG CG GGCTTTGC GC T

-MEXICO TTGTTGTTGTGCCCACTCGCGAGCTTCGGAACGCTTGGCGGCGCCGGGGCTTTGCGGCAT

3070v 3080v 3090v 3100v 3110v 3120v -BURMA TTACCCCGCATACTGCCGCCAGAGTCACCCAGGGGCGCCGGGTTGTCATTGATGAGGCTC T AC CCGCA ACTGC GCC G GTCAC GG CG GGGTTGTCATTGATGAGGC C -MEXICO TCACTCCGCACACTGCGGCCCGTGTCACTAGCGGCCGTAGGGTTGTCATTGATGAGGCCC

3130v 3140v 3150v 3160v 3170v 3180v -BURMA CATCCCTCCCCCCTCACCTGCTGCTGCTCCACATGCAGCGGGCCGCCACCGTCCACCTTC C TC CTCCCCCC CAC TGCTGCT T CA ATGCAGCG GC GC C GT CACCT C -MEXICO CTTCGCTCCCCCCACACTTGCTGCTTTTACATATGCAGCGTGCTGCATCTGTGCACCTCC

3190v 3200v 3210v 3220v 3230v 3240v -BURMA TTGGCGACCCGAACCAGATCCCAGCCATCGACTTTGAGCACGCTGGGCTCGTCCCCGCCA TTGG GACCCGAA CAGATCCC GCCAT GA TTTGAGCAC C GG CT T CC GC A -MEXICO TTGGGGACCCGAATCAGATCCCCGCCATAGATTTTGAGCACACCGGTCTGATTCCAGCAA

3250v 3260v 3270v 3280v 3290v 3300v -BURMA TCAGGCCCGACTTAGGCCCCACCTCCTGGTGGCATGTTACCCATCGCTGGCCTGCGGATG T GGCC GA TT G CCC AC TC TGGTGGCATGT ACCCA CG TG CCTGC GATG -MEXICO TACGGCCGGAGTTGGTCCCGACTTCATGGTGGCATGTCACCCACCGTTGCCCTGCAGATG

3310v 3320v 3330v 3340v 3350v 3360v -BURMA TATGCGAGCTCATCCGTGGTGCATACCCCATGATCCAGACCACTAGCCGGGTTCTCCGTT T TG GAG T TCCGTGGTGC TACCC A ATCCAGAC AC AG GGT CTCCGTT -MEXICO TCTGTGAGTTAGTCCGTGGTGCTTACCCTAAAATCCAGACTACAAGTAAGGTGCTCCGTT

3370v 3380v 3390v 3400v 3410v 3420v -BURMA CGTTGTTCTGGGGTGAGCCTGCCGTCGGGCAGAAACTAGTGTTCACCCAGGCGGCCAAGC C T TTCTGGGG GAGCC GC GTCGG CAGAA CTAGTGTTCAC CAGGC GC AAG -MEXICO CCCTTTTCTGGGGAGAGCCAGCTGTCGGCCAGAAGCTAGTGTTCACACAGGCTGCTAAGG

3430v 3440v 3450v 3460v 3470v 3480v -BURMA CCGCCAACCCCGGCTCAGTGACGGTCCACGAGGCGCAGGGCGCTACCTACACGGAGACCA CCGC ACCCCGG TC T ACGGTCCA GAGGC CAGGG GC AC T AC AC A -MEXICO CCGCGCACCCCGGATCTATAACGGTCCATGAGGCCCAGGGTGCCACTTTTACCACTACAA

3490v 3500v 3510v 3520v 3530v 3540v -BURMA CTATTATTGCCACAGCAGATGCCCGGGGCCTTATTCAGTCGTCTCGGGCTCATGCCATTG CTAT ATTGC AC GCAGATGCCCG GGCCT AT CAGTC TC CGGGCTCA GC AT G -MEXICO CTATAATTGCAACTGCAGATGCCCGTGGCCTCATACAGTCCTCCCGGGCTCACGCTATAG

3550v 3560v 3570v 3580v 3590v 3600v -BURMA TTGCTCTGACGCGCCACACTGAGAAGTGCGTCATCATTGACGCACCAGGCCTGCTTCGCG TTGCTCT AC G CA ACTGA AA TG GT AT TTGAC C CC GGCCTG T CG G -MEXICO TTGCTCTCACTAGGCATACTGAAAAATGTGTTATACTTGACTCTCCCGGCCTGTTGCGTG

3610v 3620v 3630v 3640v 3650v 3660v ■BURMA AGGTGGGCATCTCCGATGCAATCGTTAATAACTTTTTCCTCGCTGGTGGCGAAATTGGTC AGGTGGG ATCTC GATGC AT GTTAATAA TT TTCCT C GGTGGCGA TTGGTC -MEXICO AGGTGGGTATCTCAGATGCCATTGTTAATAATTTCTTCCTTTCGGGTGGCGAGGTTGGTC

3670v 3680v 3690v 3700v 3710v 3720v

-BURMA ACCAGCGCCCATCAGTTATTCCCCGTGGCAACCCTGACGCCAATGTTGACACCCTGGCTG

ACCAG G CCATC GT ATTCC CG GGCAACCCTGAC CAATGTTGAC CT GC G

-MEXICO ACCAGAGACCATCGGTCATTCCGCGAGGCAACCCTGACCGCAATGTTGACGTGCTTGCGG

3730v 3740v 3750v 3760v 3770v 3780v -BURMA CCTTCCCGCCGTCTTGCCAGATTAGTGCCTTCCATCAGTTGGCTGAGGAGCTTGGCCACA

C TT CC CC TC TGCCA AT AG GCCTTCCATCAG T GCTGAGGAGCT GGCCAC -MEXICO CGTTTCCACCTTCATGCCAAATAAGCGCCTTCCATCAGCTTGCTGAGGAGCTGGGCCACC

3790v 3800v 3810v 3820v 3830v 3840v -BURMA GACCTGTCCCTGTTGCAGCTGTTCTACCACCCTGCCCCGAGCTCGAACAGGGCCTTCTCT G CC G CC GT GC GCTGT CTACC CCCTGCCC GAGCT GA CAGGGCCTTCTCT -MEXICO GGCCGGCGCCGGTGGCGGCTGTGCTACCTCCCTGCCCTGAGCTTGAGCAGGGCCTTCTCT

3850v 3860v 3870v 3880v 3890v 3900v -BURMA ACCTGCCCCAGGAGCTCACCACCTGTGATAGTGTCGTAACATTTGAATTAACAGACATTG A CTGCC CAGGAGCT CC CCTGTGA AGTGT GT ACATTTGA TAAC GACATTG -MEXICO ATCTGCCACAGGAGCTAGCCTCCTGTGACAGTGTTGTGACATTTGAGCTAACTGACATTG

3910v 3920v 3930v 3940v 3950v 3960v -BURMA TGCACTGCCGCATGGCCGCCCCGAGCCAGCGCAAGGCCGTGCTGTCCACACTCGTGGGCC TGCACTGCCGCATGGC GCCCC AGCCA G AA GC GT TGTCCAC CT GT GGCC -MEXICO TGCACTGCCGCATGGCGGCCCCTAGCCAAAGGAAAGCTGTTTTGTCCACGCTGGTAGGCC

3970v 3980v 3990v 4000v 4010v 4020v

-BURMA GCTACGGCGGTCGCACAAAGCTCTACAATGCπCCCACTCTGATGTTCGCGACTCTCTCG G TA GGC G CGCACAA GCT TA ATGC CAC C GATGT CGCG CTC CT G -MEXICO GGTATGGCAGACGCACAAGGCTTTATGATGCGGGTCACACCGATGTCCGCGCCTCCCTTG

4030v 4040v 4050v 4060v 4070v 4080v -TASHKENT GGCCCCGTACAGGTCACAACCTGTGAGTTGTACGAGCTAG

GGCCCCGTACAGGT ACAAC TGTGA TTGTACGAGCTAG

-BURMA CCCGTTTTATCCCGGCCATTGGCCCCGTACAGGTTACAACTTGTGAATTGTACGAGCTAG

C CG TTTAT CC C T GG C GT G AC AC TGTGAA T T GAGCT G

-MEXICO CGCGCTTTATTCCCACTCTCGGGCGGGTTACTGCCACCACCTGTGAACTCTTTGAGCTTG

4090v 4100v 4110v 4120v 4130v 4140v -TASHKENT TGGAGGCCATGGTCGAGAAAGGCCAGGATGGCTCCGCCGTCCTTGAGCTCGATCTCTGCA

TGGAGGCCATGGTCGAGAA GGCCAGGATGGCTCCGCCGTCCTTGAGCT GATCT TGCA -BURMA TGGAGGCCATGGTCGAGAAGGGCCAGGATGGCTCCGCCGTCCTTGAGCTTGATCTTTGCA

T GAGGC ATGGT GAGAAGGGCCA GA GG TC GCCGTCCT GAG T GAT T TGCA -MEXICO TAGAGGCGATGGTGGAGAAGGGCCAAGACGGTTCAGCCGTCCTCGAGTTGGATTTGTGCA

4150v 4160v 4170v 4180v 4190v 4200v

-TASHKENT ACCGTGACGTGTCCAGGATCACCTTTTTCCAGAAAGATTGCAATAAGTTCACCACGGGAG

ACCGTGACGTGTCCAGGATCACCTT TTCCAGAAAGATTG AA AAGTTCACCAC GG G

-BURMA ACCGTGACGTGTCCAGGATCACCTTCTTCCAGAAAGATTGTAACAAGTTCACCACAGGTG

CCG GA GT TCC G AT ACCTT TTCCAGAA GATTGTAACAAGTTCAC AC GG G

-MEXICO GCCGAGATGTCTCCCGCATAACCTTTTTCCAGAAGGATTGTAACAAGTTCACGACCGGCG

4210v 4220v 4230v 4240v 4250v 4260v

-TASHKENT AGACCATCGCCCATGGTAAAGTGGGCCAGGGCATTTCGGCCTGGAGTAAGACCTTCTGTG

AGACCAT GCCCATGGTAAAGTGGGCCAGGGCATTTCGGCCTGGAG AAGACCTTCTG G

-BURMA AGACCATTGCCCATGGTAAAGTGGGCCAGGGCATCTCGGCCTGGAGCAAGACCTTCTGCG AGAC ATTGC CATGG AAAGT GG CAGGG ATCT CTGGAG AAGAC TT TG G

-MEXICO AGACAATTGCGCATGGCAAAGTCGGTCAGGGTATCTTCCGCTGGAGTAAGACGTTTTGTG

4270v 4280v 4290v 4300v 4310v 4320v

-TASHKENT CCCTTTTCGGCCCCTGGTTCCGTGCTATTGAGAAGGCTATTCTGGCCCTGCTCCCTCAGG CCCT TT GGCCC TGGTTCCG GCTATTGAGAAGGCTATTCTGGCCCTGCTCCCTCAGG

-BURMA CCCTCTTTGGCCCTTGGTTCCGCGCTATTGAGAAGGCTATTCTGGCCCTGCTCCCTCAGG

CCCT TTTGGCCC TGGTTCCG GC ATTGAGAAGGCTATTCT CCCT T CC CA G

-MEXICO CCCTGTTTGGCCCCTGGTTCCGTGCGATTGAGAAGGCTATTCTATCCCTTTTACCACAAG 4330v 4340v 4350v 4360v 4370v 4380v

-TASHKENT GTGTGTTTTATGGGGATGCCTTTGATGACACCGTCTTCTCGGCGCGTGTGGCCGCAGCAA

GTGTGTTTTA GG GATGCCTTTGATGACACCGTCTTCTCGGCG TGTGGCCGCAGCAA

-BURMA GTGTGTTTTACGGTGATGCCTTTGATGACACCGTCTTCTCGGCGGCTGTGGCCGCAGCAA

TGTGTT TACGG GATGC T TGA GAC C GT TTCTC GC GC GTGGC G GC A -MEXICO CTGTGTTCTACGGGGATGCTTATGACGACTCAGTATTCTCTGCTGCCGTGGCTGGCGCCA

4390v 4400v 4410v 4420v 4430v 4440v -TASHKENT AGGCGTCCATGGTGTTTGAGAATGACTTTTCTGAGTTTGACTCCACCCAGAATAATTTTT AGGC TCCATGGTGTTTGAGAATGACTTTTCTGAGTTTGACTCCACCCAGAATAA TTTT -BURMA AGGCATCCATGGTGTTTGAGAATGACTTTTCTGAGTTTGACTCCACCCAGAATAACTTTT

CCATGGTGTTTGA AATGA TTTTCTGAGTTTGACTC AC CAGAATAACTTTT -MEXICO GCCATGCCATGGTGTTTGAAAATGATTTTTCTGAGTTTGACTCGACTCAGAATAACTTTT

4450v 4460v 4470v 4480v 4490v 4500v -TASHKENT CCCTGGGCCTAGAGTGTGCTATTATGGAGAAGTGTGGGATGCCGAAGTGGCTCATCCGCT

C CTGGG CTAGAGTGTGCTATTATGGAG AGTGTGGGATGCCG AGTGGCTCATCCGC -BURMA CTCTGGGTCTAGAGTGTGCTATTATGGAGGAGTGTGGGATGCCGCAGTGGCTCATCCGCC

C CT GGTCT GAGTG GC ATTATGGA GAGTGTGG ATGCC CAGTGGCT TC G -MEXICO CCCTAGGTCTTGAGTGCGCCATTATGGAAGAGTGTGGTATGCCCCAGTGGCTTGTCAGGT

4510v 4520v 4530v 4540v 4550v 4560v

-TASHKENT TGTACCACCTTATAAGGTCTGCGTGGATCCTGCAGGCCCCGAAGGAGTCCCTGCGAGGGT

TGTA CACCTTATAAGGTCTGCGTGGATC TGCAGGCCCCGAAGGAGTC CTGCGAGGGT

-BURMA TGTATCACCTTATAAGGTCTGCGTGGATCTTGCAGGCCCCGAAGGAGTCTCTGCGAGGGT TGTA CA T GGTC GCGTGGATC TGCAGGCCCC AA GAGTCT TG GAGGGT

-MEXICO TGTACCATGCCGTCCGGTCGGCGTGGATCCTGCAGGCCCCAAAAGAGTCTTTGAGAGGGT

4570v 4580v 4590v 4600v 4610v 4620v

-TASHKENT GTTGGAAGAAACACTCCGGTGAGCCCGGCACTCTTCTATGGAATACTGTCTGGAACATGG TTGGAAGAAACACTCCGGTGAGCCCGGCACTCTTCTATGGAATACTGTCTGGAA ATGG

-BURMA TTTGGAAGAAACACTCCGGTGAGCCCGGCACTCTTCTATGGAATACTGTCTGGAATATGG

T TGGAAGAA CA TC GGTGAGCC GGCA T CT TGGAATAC GT TGGAA ATGG

-MEXICO TCTGGAAGAAGCATTCTGGTGAGCCGGGCAGCTTGCTCTGGAATACGGTGTGGAACATGG 4630v 4640v 4650v 4660v 4670v 4680v

-TASKENT CCGTTATCACCCATTGTTACGATTTCCGCGATTTGCAGGTGGCTGCCTTTAAAGGTGATG

CCGTTAT ACCCA TGTTA GA TTCCGCGATTT AGGTGGCTGCCTTTAAAGGTGATG

-BURMA CCGTTATTACCCACTGTTATGACTTCCGCGATTTTCAGGTGGCTGCCTTTAAAGGTGATG

C T ATT CCCA TG TATGA TTCCG GA T CAGGT GC GCCTT AA GG GA G -MEXICO CAATCATTGCCCATTGCTATGAGTTCCGGGACCTCCAGGTTGCCGCCTTCAAGGGCGACG

4690v 4700v 4710v 4720v 4730v 4740v -TASHKENT ATTCGATAGTGCTTTGCAGTGAGTACCGTCAGAGTCCAGGGGCTGCTGTCCTGATTGCTG

ATTCGATAGTGCTTTGCAGTGAGTA CGTCAGAGTCCAGG GCTGCTGTCCTGAT GC G -BURMA ATTCGATAGTGCTTTGCAGTGAGTATCGTCAGAGTCCAGGAGCTGCTGTCCTGATCGCCG

A TCG T GT CT TG AGTGA TA CG CAGAG CCAGG GC G T CT AT GC G -MEXICO ACTCGGTCGTCCTCTGTAGTGAATACCGCCAGAGCCCAGGCGCCGGTTCGCTTATAGCAG

4750v 4760v 4770v 4780v 4790v 4800v -TASHKENT GCTGTGGCTTAAAGCTGAAGGTGGGTTTCCGTCCGATTGGTTTGTATGCAGGTGTTGTGG

GCTGTGGCπ AAG TGAAGGT G TTTCCG CCGAT GGTTTGTATGCAGGTGTTGTGG -BURMA GCTGTGGCTTGAAGTTGAAGGTAGATTTCCGCCCGATCGGTTTGTATGCAGGTGTTGTGG

GCTGTGG TTGAAGTTGAAGG GA TTCCG CCGAT GG TGTATGC GG GTTGT G -MEXICO GCTGTGGTTTGAAGTTGAAGGCTGACTTCCGGCCGATTGGGCTGTATGCCGGGGTTGTCG

4810v 4820v 4830v 4840v 4850v 4860v -TASHKENT TGACCCCCGGCCTTGGCGCGCTTCCCGACGTCGTGCGCTTGTCCGGCCGGCTTACTGAGA

TG CCCCCGGCCTTGGCGCGCTTCCCGA GT GTGCGCTTG CCGGCCGGCTTAC GAGA -BURMA TGGCCCCCGGCCTTGGCGCGCTCCCTGATGHGTGCGCTTCGCCGGCCGGCTTACCGAGA

T GCCCC GG CT GG GC CT CC GATGT GT CG TTCGCCGG CGGCTT C GAGA -MEXICO TCGCCCCGGGGCTCGGGGCCCTACCCGATGTCGTTCGATTCGCCGGACGGCTTTCGGAGA

4870v 4880v 4890v 4900v 4910v 4920v -TASHKENT AGAATTGGGGCCCTGGCCCTGAGCGGGCGGAGCAGCTCCGCCTTGCTGT

AGAATTGGGGCCCTGGCCCTGAGCGGGCGGAGCAGCTCCGCCT GCTGT -BURMA AGAATTGGGGCCCTGGCCCTGAGCGGGCGGAGCAGCTCCGCCTCGCTGTTAGTGATTTCC

AGAA TGGGG CCTG CC GAGCGGGC GAGCAGCTCCGCCTCGC GT GATTTCC -MEXICO AGAACTGGGGGCCTGATCCGGAGCGGGCAGAGCAGCTCCGCCTCGCCGTGCAGGATTTCC

4930v 4940v 4950v 4960v 4970v 4980v -BURMA TCCGCAAGCTCACGAATGTAGCTCAGATGTGTGTGGATGTTGTTTCCCGTGTTTATGGGG TCCG A G T ACGAATGT GC CAGAT TGTGT GA GT GT TC G GTTTA GGGG -MEXICO TCCGTAGGTTAACGAATGTGGCCCAGATTTGTGTTGAGGTGGTGTCTAGAGTTTACGGGG

4990v 5000v 5010v 5020v 5030v 5040v -BURMA TTTCCCCTGGACTCGTTCATAACCTGATTGGCATGCTACAGGCTGTTGCTGATGGCAAGG TTTCCCC GG CT GTTCATAACCTGAT GGCATGCT CAG CT TTG TGATGG AAGG -MEXICO TTTCCCCGGGTCTGGTTCATAACCTGATAGGCATGCTCCAGACTATTGGTGATGGTAAGG

5050v 5060v 5070v 5080v 5090v 5100v -BURMA CACATTTCACTGAGTCAGTAAAACCAGTGCTCGACTTGACAAATTCAATCTTGTGTCGGG C CATTT AC GAGTC GT AA CC T CT GAC T ACA A TCAAT TG CGG -MEXICO CGCATTTTACAGAGTCTGTTAAGCCTATACTTGACCTTACACACTCAATTATGCACCGGT

5110v 5120v 5130v 5140v 5150v 5160v -BURMA TGGAATGAATAACATGTCTTTTGCTGCGCCCATGGGTTCGCGACCATGCGCCCTCGGCCT GAATGAATAACATGT TTTGCTGCGCCCATGGGTTCGC ACCATGCGCCCT GGCCT -MEXICO CTGAATGAATAACATGTGGTTTGCTGCGCCCATGGGTTCGCCACCATGCGCCCTAGGCCT

5170v 5180v 5190v 5200v 5210v 5220v

-BURMA ATTTTGTTGCTGCTCCTCATGTTΠTGCCTATGCTGCCCGCGCCACCGCCCGGTCAGCCG

TTTTG TG TG TCCTC TGTTT TGCCTATG TGCCCGCGCCACCG CCGGTCAGCCG

-MEXICO CTTTTGCTGΠGΠCCTCΠGTΠCTGCCTATGTTGCCCGCGCCACCGACCGGTCAGCCG

5230v 5240v 5250v 5260v 5270v 5280v -BURMA TCTGGCCGCCGTCGTGGGCGGCGCAGCGGCGGTTCCGGCGGTGGTTTCTGGGGTGACCGG TCTGGCCGCCGTCGTGGGCGGCGCAGCGGCGGT CCGGCGGTGGTTTCTGGGGTGACCGG -MEXICO TCTGGCCGCCGTCGTGGGCGGCGCAGCGGCGGTACCGGCGGTGGTTTCTGGGGTGACCGG

5290v 5300v 5310v 5320v 5330v 5340v -BURMA GTTGATTCTCAGCCCTTCGCAATCCCCTATATTCATCCAACCAACCCCTTCGCCCCCGAT GTTGATTCTCAGCCCTTCGCAATCCCCTATATTCATCCAACCAACCCCTT GCCCC GA -MEXICO GTTGATTCTCAGCCCTTCGCAATCCCCTATATTCATCCAACCAACCCCTTTGCCCCAGAC

5350v 5360v 5370v 5380v 5390v 5400v -BURMA GTCACCGCTGCGGCCGGGGCTGGACCTCGTGTTCGCCAACCCGCCCGACCACTCGGCTCC GT CCGCTGCG CCGGG CTGGACCTCG TTCGCCAACC GCCCG CCACT GGCTCC -MEXICO GTTGCCGCTGCGTCCGGGTCTGGACCTCGCCTTCGCCAACCAGCCCGGCCACTTGGCTCC

5410v 5420v 5430v 5440v 5450v 5460v -BURMA GCTTGGCGTGACCAGGCCCAGCGCCCCGCCGTTGCCTCACGTCGTAGACCTACCACAGCT

CTTGGCG GA CAGGCCCAGCGCCCC CCG TGCCTC CGTCG GACCT CCACAGC -MEXICO ACTTGGCGAGATCAGGCCCAGCGCCCCTCCGCTGCCTCCCGTCGCCGACCTGCCACAGCC

5470v 5480v 5490v 5500v 5510v 5520v -BURMA GGGGCCGCGCCGCTAACCGCGGTCGCTCCGGCCCATGACACCCCGCCAGTGCCTGATGTC GGGGC GCG CGCT AC GC GT GC CC GCCCATGACACC C CC GT CC GA GT -MEXICO GGGGCTGCGGCGCTGACGGCTGTGGCGCCTGCCCATGACACCTCACCCGTCCCGGACGTT

5530v 5540v 5550v 5560v 5570v 5580v -BURMA GACTCCCGCGGCGCCATCTTGCGCCGGCAGTATAACCTATCAACATCTCCCCTTACCTCT

GA TC CGCGG GC AT T CGCCG CAGTATAA T TC AC TC CCCCT AC TC -MEXICO GATTCTCGCGGTGCAATTCTACGCCGCCAGTATAATTTGTCTACTTCACCCCTGACATCC

5590v 5600v 5610v 5620v 5630v 5640v -BURMA TCCGTGGCCACCGGCACTAACCTGGTTCTTTATGCCGCCCCTCTTAGTCCGCTTTTACCC TC GTGGCC C GGCACTAA T GT CT TATGC GCCCC CTTA TCCGC T T CC -MEXICO TCTGTGGCCTCTGGCACTAATTTAGTCCTGTATGCAGCCCCCCTTAATCCGCCTCTGCCG

5650v 5660v 5670v 5680v 5690v 5700v -BURMA CTTCAGGACGGCACCAATACCCATATAATGGCCACGGAAGCTTCTAATTATGCCCAGTAC CT CAGGACGG AC AATAC CA AT ATGGCCAC GA GC TC AATTATGC CAGTAC -MEXICO CTGCAGGACGGTACTAATACTCACATTATGGCCACAGAGGCCTCCAATTATGCACAGTAC

5710v 5720v 5730v 5740v 5750v 5760v -BURMA CGGGTTGCCCGTGCCACAATCCGTTACCGCCCGCTGGTCCCCAATGCTGTCGGCGGTTAC CGGGTTGCCCG GC AC ATCCGTTACCG CC CT GT CC AATGC GT GG GG TA -MEXICO CGGGTTGCCCGCGCTACTATCCGTTACCGGCCCCTAGTGCCTAATGCAGTTGGAGGCTAT

5770v 5780v 5790v 5800v 5810v 5820v -BURMA GCCATCTCCATCTCATTCTGGCCACAGACCACCACCACCCCGACGTCCGTTGATATGAAT GC AT TCCAT TC TTCTGGCC CA AC ACCAC ACCCC AC TC GTTGA ATGAAT -MEXICO GCTATATCCATTTCTTTCTGGCCTCAAACAACCACAACCCCTACATCTGTTGACATGAAT

5830v 5840v 5850v 5860v 5870v 5880v -BURMA TCAATAACCTCGACGGATGTTCGTATTTTAGTCCAGCCCGGCATAGCCTCTGAGCTTGTG TC AT AC TC AC GATGT G ATT T GT CA CC GGCATAGC TCTGA T GT -MEXICO TCCATTACTTCCACTGATGTCAGGATTCTTGTTCAACCTGGCATAGCATCTGAATTGGTC

5890v 5900v 5910v 5920v 5930v 5940v -BURMA ATCCCAAGTGAGCGCCTACACTATCGTAACCAAGGCTGGCGCTCCGTCGAGACCTCTGGG ATCCCAAG GAGCGCCT CACTA CG AA CAAGG TGGCGCTC GT GAGAC TCTGG -MEXICO ATCCCAAGCGAGCGCCTTCACTACCGCAATCAAGGTTGGCGCTCGGTTGAGACATCTGGT

5950v 5960v 5970v 5980v 5990v 6000v -BURMA GTGGCTGAGGAGGAGGCTACCTCTGGTCTTGTTATGCTTTGCATACATGGCTCACTCGTA GT GCTGAGGAGGA GC ACCTC GGTCTTGT ATG T TGCATACATGGCTC C GT -MEXICO GTTGCTGAGGAGGAAGCCACCTCCGGTCTTGTCATGTTATGCATACATGGCTCTCCAGTT

6010v 6020v 6030v 6040v 6050v 6060v -BURMA AATTCCTATACTAATACACCCTATACCGGTGCCCTCGGGCTGTTGGACTTTGCCCTTGAG AA TCCTATAC AATAC CC TATACCGGTGCCCT GG T TGGACTTTGCC T GAG -MEXICO AACTCCTATACCAATACCCCTTATACCGGTGCCCTTGGCTTACTGGACTTTGCCTTAGAG

6070v 6080v 6090v 6100v 6110v 6120v -BURMA CTTGAGTTTCGCAACCTTACCCCCGGTAACACCAATACGCGGGTCTCCCGTTATTCCAGC CTTGAGTTTCGCAA CT ACC CC GTAACACCAATAC CG GT TCCCGTTA TCCAGC -MEXICO CTTGAGTTTCGCAATCTCACCACCTGTAACACCAATACACGTGTGTCCCGTTACTCCAGC

6130v 6140v 6150v 6160v 6170v 6180v -BURMA ACTGCTCGCCACCGCCTTCGTCGCGGTGCGGACGGGACTGCCGAGCTCACCACCACGGCT

ACTGCTCG CAC C CG G G GACGGGACTGC GAGCT ACCAC AC GC -MEXICO ACTGCTCGTCACTCCGCCCGAGGGGCC—GACGGGACTGCGGAGCTGACCACAACTGCA

6190v 6200v 6210v 6220v 6230v 6240v -BURMA GCTACCCGCTTTATGAAGGACCTCTATTTTACTAGTACTAATGGTGTCGGTGAGATCGGC GC ACC G TT ATGAA GA CTC A TTTAC G TAATGG GT GGTGA TCGGC -MEXICO GCCACCAGGTTCATGAAAGATCTCCACTTTACCGGCCTTAATGGGGTAGGTGAAGTCGGC

6250v 6260v 6270v 6280v 6290v 6300v

-BURMA CGCGGGATAGCCCTCACCCTGTTCAACCHGCTGACACTCTGCTTGGCGGCCTGCCGACA CGCGGGATAGC CT AC T T AACCTTGCTGACAC CT CT GGCGG CT CCGACA -MEXICO CGCGGGATAGCTCTAACATTACTTAACCTTGCTGACACGCTCCTCGGCGGGCTCCCGACA

6310v 6320v 6330v 6340v 6350v 6360v -BURMA GAATTGATTTCGTCGGCTGGTGGCCAGCTGTTCTACTCCCGTCCCGTTGTCTCAGCCAAT GAATT ATTTCGTCGGCTGG GG CA CTGTT TA TCCCG CC GTTGTCTCAGCCAAT -MEXICO GAATTAATTTCGTCGGCTGGCGGGCAACTGTTTTATTCCCGCCCGGTTGTCTCAGCCAAT

6370v 6380v 6390v 6400v 6410v 6420v -BURMA GGCGAGCCGACTGTTAAGTTGTATACATCTGTAGAGAATGCTCAGCAGGATAAGGGTATT GGCGAGCC AC GT AAG T TATACATC GT GAGAATGCTCAGCAGGATAAGGGT TT -MEXICO GGCGAGCCAACCGTGAAGCTCTATACATCAGTGGAGAATGCTCAGCAGGATAAGGGTGTT

6430v 6440v 6450v 6460v 6470v 6480v -BURMA GCAATCCCGCATGACATTGACCTCGGAGAATCTCGTGTGGTTATTCAGGATTATGATAAC GC ATCCC CA GA AT GA CT GG GA TC CGTGTGGT ATTCAGGATTATGA AAC -MEXICO GCTATCCCCCACGATATCGATCTTGGTGATTCGCGTGTGGTCATTCAGGATTATGACAAC

6490v 6500v 6510v 6520v 6530v 6540v -BURMA CAACATGAACAAGATCGGCCGACGCCTTCTCCAGCCCCATCGCGCCCTTTCTCTGTCCTT

CA CATGA CA GATCGGCC AC CC TC CC GC CCATC CG CCTTT TCTGT CT -MEXICO CAGCATGAGCAGGATCGGCCCACCCCGTCGCCTGCGCCATCTCGGCCTTTTTCTGTTCTC

6550v 6560v 6570v 6580v 6590v 6600v -BURMA CGAGCTAATGATGTGCTTTGGCTCTCTCTCACCGCTGCCGAGTATGACCAGTCCACTTAT

CGAGC AATGATGT CTTTGGCT TC CTCAC GC GCCGAGTATGACCAGTCCACTTA -MEXICO CGAGCAAATGATGTACTTTGGCTGTCCCTCACTGCAGCCGAGTATGACCAGTCCACTTAC

6610v 6620v 6630v 6640v 6650v 6660v -BURMA GGCTCTTCGACTGGCCCAGTTTATGTTTCTGACTCTGTGACCTTGGTTAATGTTGCGACC GG TC TC ACTGGCCC GTTTAT T TC GAC GTGAC TTGGT AATGTTGCGAC -MEXICO GGGTCGTCAACTGGCCCGGTTTATATCTCGGACAGCGTGACTTTGGTGAATGTTGCGACT

6670v 6680v 6690v 6700v 6710v 6720v -BURMA GGCGCGCAGGCCGTTGCCCGGTCGCTCGATTGGACCAAGGTCACACTTGACGGTCGCCCC GGCGCGCAGGCCGT GCCCG TCGCT GA TGG CCAA GTCAC CT GACGG CG CCC -MEXICO GGCGCGCAGGCCGTAGCCCGATCGCTTGACTGGTCCAAAGTCACCCTCGACGGGCGGCCC

6730v 6740v 6750v 6760v 6770v 6780v -BURMA CTCTCCACCATCCAGCAGTACTCGAAGACCTTCTTTGTCCTGCCGCTCCGCGGTAAGCTC CTC C AC T AGCA TA TC AAGAC TTCTTTGT CT CC CT CG GG AAGCTC -MEXICO CTCCCGACTGTTGAGCAATATTCCAAGACATTCTTTGTGCTCCCCCTTCGTGGCAAGCTC

6790v 6800v 6810v 6820v 6830v 6840v -BURMA TCTTTCTGGGAGGCAGGCACAACTAAAGCCGGGTACCCTTATAATTATAACACCACTGCT TC TT TGGGAGGC GGCACAAC AAAGC GG TA CCTTATAATTATAA AC ACTGCT -MEXICO TCCTTTTGGGAGGCCGGCACAACAAAAGCAGGTTATCCTTATAATTATAATACTACTGCT

6850v 6860v 6870v 6880v 6890v 6900v -BURMA AGCGACCAACTGCTTGTCGAGAATGCCGCCGGGCACCGGGTCGCTATTTCCACTTACACC AG GACCA T CT T GA AATGC GCCGG CA CGGGTCGC ATTTC AC TA ACC -MEXICO AGTGACCAGATTCTGATTGAAAATGCTGCCGGCCATCGGGTCGCCATTTCAACCTATACC

6910v 6920v 6930v 6940v 6950v 6960v -BURMA ACTAGCCTGGGTGCTGGTCCCGTCTCCATTTCTGCGGTTGCCGTTTTAGCCCCCCACTCT

AC AG CT GG GC GGTCC GTC CCATTTCTGCGG GC GTTTT GC CC C CTC -MEXICO ACCAGGCTTGGGGCCGGTCCGGTCGCCATTTCTGCGGCCGCGGTTTTGGCTCCACGCTCC

6970v 6980v 6990v 7000v 7010v 7020v -BURMA GCGCTAGCATTGCTTGAGGATACCTTGGACTACCCTGCCCGCGCCCATACTTTTGATGAT GC CT GC TGCT GAGGATAC TT GA TA CC G CG GC CA AC TTTGATGA -MEXICO GCCCTGGCTCTGCTGGAGGATACTTTTGATTATCCGGGGCGGGCGCACACATTTGATGAC

7030v 7040v 7050v 7060v 7070v 7080v -BURMA TTCTGCCCAGAGTGCCGCCCCCTTGGCCTTCAGGGCTGCGCTTTCCAGTCTACTGTCGCT TTCTGCCC GA TGCCGC C T GGCCT CAGGG TG GCTTTCCAGTC ACTGTCGCT -MEXICO TTCTGCCCTGAATGCCGCGCTTTAGGCCTCCAGGGTTGTGCTTTCCAGTCAACTGTCGCT

7090v 7100v 7110v 7120v 7130v 7140v -BURMA GAGCTTCAGCGCCTTAAGATGAAGGTGGGTAAAACTCGGGAGTTGTAGTTTATTTGCTTG GAGCT CAGCGCCTTAA T AAGGTGGGTAAAACTCGGGAGTTGTAGTTTATTTG TG -MEXICO GAGCTCCAGCGCCTTAAAGTTAAGGTGGGTAAAACTCGGGAGTTGTAGTTTATTTGGCTG

7150v 7160v 7170v 7180v 7190v

-BURMA TGCCCCCCTTCTTTCTGTTGC TTATTTCTCATTTCTGCGTTCCGCGCTCCC

TGCCC CCT CTT TGC TTATTTC TTTCT GT CCGCGCTCCC -MEXICO TGCCCACCTACTTATATCTGCTGA CCTTTATTTCCTTTTTCTCGGTCCCGCGCTCCC v 7195 -BURMA TGA TGA -MEXICO TGA

A number of open reading frames, which are potential coding regions, have been found within the DNA sequences set forth above. As has already been noted, consensus residues for the RNA-directed RNA polymerase (RDRP) were identified in the HEV (Burma) strain clone ETl.l. Once a contiguous overlapping set of clones was accumulated, it became clear that the nonstructural elements containing the RDRP as well as what were identified as consensus residues for the helicase domain were located in the first large open reading frame (ORFI). ORFI covers the 5' half of the genome and begins at the first encoded met, after the 27th bp of the apparent non-coding sequence, and then extends 5079 bp before reaching a termination codon.

Beginning 37 bp downstream from the ORFI stop codon in the plus 1 frame is the second major opening reading frame (ORF2) extending 1980 bp and terminating 68 bp upstream from the point of poly A addition. The third forward ORF (in the plus 2 frame) is also utilized by HEV. ORF3 is only 370 bp in length and would not have been predicted to be utilized by the virus were it not for the identification of the immunoreactive cDNA clone 406.4-2 from the Mexico SISPA cDNA library (see below for detailed discussion) . This epitope confirmed the utilization of ORF3 by the virus, although the means by which this ORF is expressed has not yet been fully elucidated. If we assume that the first met is utilized, ORF3 overlaps ORFI by 1 bp at its 5' end and 0RF2 by 328 bp at its 3'end. ORF2 contains the broadly reactive 406.3-2 epitope and also

a signal sequence at its extreme 5' end. The first half of this 0RF2 also has a high pi value (>10) similar to that seen with other virus capsid proteins. These data suggest that the ORF2 might be the predominant structural gene of HEV.

The existence of subgenomic transcripts prompted a set of experiments to determine whether these RNAs were produced by splicing from the 5' end of the genome. An analysis using subgenomic probes from throughout the genome, including the extreme 5' end, did not provide evidence for a spliced transcript. However, it was discovered that a region of the genome displayed a high degree of homology with a 21 bp segment identified in Sindbis as a probably internal initiation site for RNA transcription used in the production of its subgenomic messages. Sixteen of 21 (76%) of the nucleotides are identical.

Two cDNA clones which encode an epitope of HEV that is recognized by sera collected from different ET-NANB outbreaks (i.e., a universally recognized epitope) have been isolated and characterized. One of the clones immunoreacted with 8 human sera from different infected individuals and the other clone immunoreacted with 7 of the human sera tested. Both clones immunoreacted specifically with cyno sera from infected animals and exhibited no immunologic response to sera from uninfected animals. The sequences of the cDNAs in these recombinant phages, designated 406.3-2 and 406.4-2 have been determined. The HEV open reading frames are shown to encode epitopes specifically recognized by sera from patients with HEV infections. The cDNA sequences and the polypeptides that they encode are set forth below.

Epitopes derived from Mexican strain of HEV: 406.4-2 sequence (nucleotide sequence has SEQ ID NO.13; amino acid sequence has SEQ ID NO.14):

SEQ ID NO. 13 :

C GCC AAC CAG CCC GGC CAC TTG GCT CCA CTT GGC GAG ATC AGG CCC 46 Ala Asn Gin Pro Gly His Leu Ala Pro Leu Gly Glu Ile Arg Pro 1 5 10 15

AGC GCC CCT CCG CTG CCT CCC GTC GCC GAC CTG CCA CAG CCG GGG CTG 94 Ser Ala Pro Pro Leu Pro Pro Val Ala Asp Leu Pro Gin Pro Gly Leu 20 25 30

CGG CGC TGA CGGCTGTGGC GCCTGCCCAT GACACCTCAC CCGTCCCGGA 143

Arg Arg .

CGTTGATTCT CGCGGTGCAA TTCTACGCCG CCAGTATAAT TTGTCTACTT CACCCCTGAC 203

ATCCTCTGTG GCCTCTGGCA CTAATTTAGT CCTGTATGCA GCCCCCCTTA ATCCGCCTCT 263

GCCGCTGCAG GACGGTACTA ATACTCACAT TATGGCCACA GAGGCCTCCA ATTATGCACA 323

GTACCGGGTT GCCCGCGCTA CTATCCGTTA CCGGCCCCTA GTGCCTAATG CAGTTGGAGG 383

CTATGCTATA TCCATTTCTT TCTGGCCTCA AACAACCACA ACCCCTACAT CTGTTGACAT 443 GAATTC 449

SEQ ID NO. 14:

Ala Asn Gin Pro Gly His Leu Ala Pro Leu Gly Glu Ile Arg Pro Ser 1 5 10 15

Ala Pro Pro Leu Pro Pro Val Ala Asp Leu Pro Gin Pro Gly Leu Arg 20 25 30 Arg .

406.3-2 sequence (nucleotide sequence has SEQ

ID NO.15; amino acid sequence has SEQ ID NO.16):

SEQ ID NO. 15:

GGAT ACT TTT GAT TAT CCG GGG CGG GCG CAC ACA TTT GAT GAC TTC TGC 49 Thr Phe Asp Tyr Pro Gly Arg Ala His Thr Phe Asp Asp Phe Cys 1 5 10 15 CCT GAA TGC CGC GCT TTA GGC CTC CAG GGT TGT GCT TTC CAG TCA ACT 97

Pro Glu Cys Arg Ala Leu Gly Leu Gin Gly Cys Ala Phe Gin Ser Thr 20 25 30

GTC GCT GAG CTC CAG CGC CTT AAA GTT AAG GTT 130 Val Ala Glu Leu Gin Arg Leu Lys Val Lys Val

35 40

SEQ ID NO. 16 :

Thr Phe Asp Tyr Pro Gly Arg Ala His Thr Phe Asp Asp Phe Cys Pro 1 5 10 15

Glu Cys Arg Ala Leu Gly Leu Gin Gly Cys Ala Phe Gin Ser Thr Val 20 25 30

Al a Glu Leu Gin Arg Leu Lys Val Lys Val 35 40

The universal nature of these epitopes is evident from the homology exhibited by the DNA that encodes them . If the epitope coding sequences from the Mexican strains shown above are compared to DNA sequences from other strains , such as the Burmese strain also set forth above , similarities are evident , as shown in the following comparisons . Comparison of 406 .4-2 epitopes , HEV Mexico and Burma strains : 10 20 30

MEXICAN(SEQ ID NO.17) ANQPGHLAPLGEIRPSAPPLPPVADLPQPGLRR

BURMA(SEQ ID NO.18) ANPPDHSAPLGVTRPSAPPLPHWDLPQLGPRR

10 20 30

There is 73.5% identity in a 33-amino acid overlap.

Comparison of 406.3-2 epitopes, HEV Mexico and Burma strains MEXICAN(SEQ ID No.19) 10 20 30 40 FDYPGRAHTΓODFCPECRALGLQGCAFQSTVAELQRLKVKV

TLDYPARAHTFDDFCPECRPLGLQGCAFQSTVAELQRLKMKV 10 20 30 40 BURMA(SEQ ID No.20)

There is 90.5% identity in the 42-amino acid overlap.

It will be recognized by one skilled in the art of molecular genetics that each of the specific DNA sequences given above shows a corresponding complementary DNA sequence as well as RNA sequences corresponding to both the principal sequence shown and

the complementary DNA sequence. Additionally, open reading frames encoding peptides are present, and expressible peptides are disclosed by the nucleotide sequences without setting forth the amino acid sequences explicitly, in the same manner as if the amino acid sequences were explicitly set forth as in the ETl.1 sequence or other sequences above.

DETAILED DESCRIPTION OF THE INVENTION I. Definitions

The terms defined below have the following meaning herein:

1. "Enterically transmitted non-A/non-B hepatitis viral agent, ET-NANB, or HEV" means a virus, virus type, or virus class which (1) causes water- borne, infectious hepatitis, (ii) is transmissible in cynomolgus monkeys, (iii) is serologically distinct from hepatitis A virus (HAV) , hepatitis B virus (HBV), hepatitis C virus (HCV), and hepatitis D virus, and (iv) includes a genomic region which is homologous to the 1.33 kb cDNA insert in plasmid pTZKFl(ETl.1) carried in E_^ coli strain BB4 identified by ATCC deposit number 67717.

2. Two nucleic acid fragments are "homologous" if they are capable of hybridizing to one another under hybridization conditions described in Maniatis et al. , op. cit. , pp. 320-323. However, using the following wash conditions: 2 x SCC, 0.1% SDS, room temperature twice, 30 minutes each; then 2 x SCC, 0.1% SDS, 50°C once, 30 minutes; then 2 x SCC, room temperature twice, 10 minutes each, homologous sequences can be identified that contain at most about 25-30% basepair mismatches. More preferably, homologous nucleic acid strands contain 15-25% basepair mismatches, even more preferably 5-15% basepair mismatches. These degrees of homology can be selected by using more stringent wash conditions for identification of clones from gene libraries (or

other sources of genetic material), as is well known in the art.

3. Two amino acid sequences or two nucleotide sequences (in an alternative definition for homology between two nucleotide sequences) are considered homologous (as this term is preferably used in this specification) if they have an alignment score of >5 (in standard deviation units) using the program ALIGN with the mutation gap matrix and a gap penalty of 6 or greater. See Dayhoff, M.O., in Atlas of Protein Sequence and Structure (1972) Vol. 5, National Biomedical Research Foundation, pp. 101-110, and Supplement 2 to this volume, pp. 1-10. The two sequences (or parts thereof, preferably at least 30 amino acids in length) are more preferably homologous if their amino acids are greater than or equal to 50% identical when optimally aligned using the ALIGN program mentioned above.

4. A DNA fragment is "derived from" an ET-NANB viral agent if it has the same or substantially the same basepair sequence as a region of the viral agent genome.

5. A protein is "derived from" an ET-NANB viral agent if it is encoded by an open reading frame of a DNA or RNA fragment derived from an ET-NANB viral agent.

II. Obtaining Cloned ET-NANB Fragments

According to one aspect of the invention, it has been found that a virus-specific DNA clone can be produced by (a) isolating RNA from the bile of a cynomolgus monkey having a known ET-NANB infection,

(b) cloning the cDNA fragments to form a fragment library, and (c) screening the library by differential hybridization to radiolabeled cDNAs from infected and non-infected bile sources.

A. cDNA Fragment Mixture

ET-NANB infection in cynomolgus monkeys is initiated by inoculating the animals intravenously with a 10% w/v suspension from human case stools positive for 27-34 nm ET-NANB particles (mean diameter 32 nm) . An infected animal is monitored for elevated levels of alanine aminotransferase, indicating hepatitis infection. ET-NANB infection is confirmed by immunospecific binding of seropositive antibodies to virus-like particles (VLPs), according to published methods (Gravelle) . Briefly, a stool (or bile) specimen taken from the infected animal 3-4 weeks after infection is diluted 1:10 with phosphate- buffered saline, and the lot suspension is clarified by low-speed centrifugation and filtration successively through 1.2 and 0.45 micron filters. The material may be further purified by pelleting through a 30% sucrose cushion (Bradley) . The resulting preparation of VLPs is mixed with diluted serum from human patients with known ET-NANB infection. After incubation overnight, the mixture is centrifuged overnight to pellet immune aggregates, and these are stained and examined by electron microscopy for antibody binding to the VLPs.

ET-NANB infection can also be confirmed by seroconversion to VLP-positive serum. Here the serum of the infected animal is mixed as above with 27-34 nm VLPs isolated from the stool specimens of infected human cases and examined by immune electron microscopy for antibody binding to the VLPs. Bile can be collected from ET-NANB positive animals by either cannulating the bile duct and collecting the bile fluid or by draining the bile duct during necropsy. Total RNA is extracted from the bile by hot phenol extraction, as outlined in Example IA. The RNA fragments are used to synthesize corresponding duplex cDNA fragments by random priming, also as referenced in Example IA. The cDNA fragments may be fractionated by gel electrophoresis or density

gradient centrifugation to obtain a desired size class of fragments, e.g., 500-4,000 basepair fragments.

Although alternative sources of viral material, such as VLPs obtained from stool samples (as described in Example 4), may be used for producing a

CDNA fraction, the bile source is preferred. According to one aspect of the invention, it has been found that bile from ET-NANB-infected monkeys shows a greater number of intact viral particles than material obtained from stool samples, as evidenced by immune electron microscopy. Bile obtained from an ET-NANB infected human or cynomolgus macaque, for use as a source of ET-NANB viral protein or genomic material, or intact virus, forms part of the present invention.

B. cDNA Library and Screening

The cDNA fragments from above are cloned into a suitable cloning vector to form a cDNA library. This may be done by equipping blunt-ended fragments with a suitable end linker, such as an EcoRI sequence, and inserting the fragments into a suitable insertion site of a cloning vector, such as at a unique EcoRI site. After initial cloning, the library may be re-cloned, if desired, to increase the percentage of vectors containing a fragment insert. The library construction described in Example IB is illustrative. Here cDNA fragments were blunt-ended, equipped with EcoRI ends, and inserted into the EcoRI site of the lambda phage vector gtlO. The library phage, which showed less than 5% fragment inserts, was isolated, and the fragment inserts re-cloned into the lambda gtlO vector, yielding more than 95% insert-containing phage. The cDNA library is screened for sequences specific for ET-NANB by differential hybridization to cDNA probes derived from infected and non-infected sources. cDNA fragments from infected and non-infected source bile or stool viral isolates can be prepared as above. Radiolabeling the fragments is by random

labeling, nick translation, or end labeling, according to conventional methods (Maniatis, p. 109). The cDNA library from above is screened by transfer to duplicate nitrocellulose filters, and hybridization with both infected-source and non-infected-source

(control) radiolabeled probes, as detailed in Example 2. In order to recover sequences that hybridize at the preferred outer limit of 25-30% basepair mismatches, clones can be selected if they hybridize under the conditions described in Maniatis et al. , op. cit. , pp. 320-323, but using the following wash conditions: 2 x SCC, 0.1% SDS, room temperature - twice, 30 minutes each; then 2 x SCC, 0.1% SDS, 50°C - once, 30 minutes; then 2 x SCC, room temperature - twice, 10 minutes each. These conditions allowed identification of the Mexican isolate discussed above using the ET1.1 sequence as a probe. Plaques which show selective hybridization to the infected-source probes are preferably re-plated at low plating density and re- screened as above, to isolate single clones which are specific for ET-NANB sequences. As indicated in Example 2, sixteen clones which hybridized specifically with infected-source probes were identified by these procedures. One of the clones, designated lambda gtlOl.l, contained a 1.33 kilobase fragment insert.

C. ET-NANB Sequences

The basepair sequence of cloned regions of the ET-NANB fragments from Part B are determined by standard sequencing methods. In one illustrative method, described in Example 3, the fragment insert from the selected cloning vector is excised, isolated by gel electrophoresis, and inserted into a cloning vector whose basepair sequence on either side of the insertion site is known. The particular vector employed in Example 3 is a pTZKFl vector shown at the left in Figure 1. The ET-NANB fragment from the gtlO-

1.1 phage was inserted at the unique EcoRI site of the pTZKFl plasmid. Recombinants carrying the desired insert were identified by hybridization with the isolated 1.33 kilobase fragment, as described in Example 3. One selected plasmid, identified as pTZKFl (ET1.1), gave the expected 1.33 kb fragment after vector digestion with EcoRI. E. coli strain BB4 infected with the pTZKFl(ET1.1) plasmid has been deposited with the American Type Culture Collection, Rockville, MD, and is identified by ATCC deposit number 67717.

The pTZKFl(ET1.1) plasmid is illustrated at the bottom in Figure 1. The fragment insert has 5' and 3' end regions denoted at A and C, respectively, and an intermediate region, denoted at B. The sequences in these regions were determined by standard dideoxy sequencing and were set forth in an earlier application in this series. The three short sequences (A, B, and C) are from the same insert strand. As will be seen in Example 3, the B-region sequence was actually determined from the opposite strand, so that the B region sequence shown above represents the complement of the sequence in the sequenced strand. The base numbers of the partial sequences are approximate.

Later work in the laboratory of the inventors identified the full sequence, set forth above. Fragments of this total sequence can readily be prepared using restriction endonucleases. Computer analysis of both the forward and reverse sequence has identified a number of cleavage sites.

III. ET-NANB Fragments

According to another aspect, the invention includes ET-NANB-specific fragments or probes which hybridize with ET-NANB genomic sequences or cDNA fragments derived therefrom. The fragments may include full-length cDNA fragments such as described in

Section II, or may be derived from shorter sequence regions within cloned cDNA fragments. Shorter fragments can be prepared by enzymatic digestion of full-length fragments under conditions which yield desired-sized fragments, as will be described in Section IV. Alternatively, the fragments can be produced by oligonucleotide synthetic methods, using sequences derived from the cDNA fragments. Methods or commercial services for producing selected-sequence oligonucleotide fragments are available. Fragments are usually at least 12 nucleotides in length, preferably at least 14, 20, 30 or 50 nucleotides, when used as probes. Probes can be full length or less than 500, preferably less than 300 or 200, nucleotides in length.

To confirm that a given ET-NANB fragment is in fact derived from the ET-NANB viral agent, the fragment can be shown to hybridize selectively with cDNA from infected sources. By way of illustration, to confirm that the 1.33 kb fragment in the pTZKFl(ET1.1) plasmid is ET-NANB in origin, the fragment was excised from the pTZKFl(ET1.1) plasmid, purified, and radiolabeled by random labeling. The radiolabeled fragment was hybridized with fractionated cDNAs from infected and non-infected sources to confirm that the probe reacts only with infected-source cDNAs. This method is illustrated in Example 4, where the above radiolabeled 1.33 kb fragment from pTZKFl(ET1.1) plasmid was examined for binding to cDNAs prepared from infected and non-infected sources. The infected sources are (1) bile from a cynomolgus macaque infected with a strain of virus derived from stool samples from human patients from Burma with known ET- NANB infections and (2) a viral agent derived from the stool sample of a human ET-NANB patient from Mexico. The cDNAs in each fragment mixture were first amplified by a linker/primer amplification method described in Example 4. Fragment separation was on

agarose gel, followed by Southern blotting and then hybridization to bind the radiolabeled 1.33 kb fragment to the fractionated cDNAs. The lane containing cDNAs from the infected sources showed a smeared band of bound probe, as expected (cDNAs amplified by the linker/primer amplification method would be expected to have a broad range of sizes). No probe binding to the amplified cDNAs from the non- infected sources was observed. The results indicate that the 1.33 kb probe is specific for cDNA fragments associated with ET-NANB infection. This same type of study, using ET 1.1 as the probe, has demonstrated hybridization to ET-NANB samples collected from Tashkent, Somalia, Borneo and Pakistan. Secondly, the fact that the probe is specific for ET-NANB related sequences derived from different continents (Asia, Africa and North America) indicates the cloned ET-NANB Burma sequence (ET1.1) is derived from a common ET- NANB virus or virus class responsible for ET-NANB hepatitis infection worldwide.

In a related confirmatory study, probe binding to fractionated genomic fragments prepared from human or cynomolgus macaque genomic DNA (both infected and uninfected) was examined. No probe binding was observed to either genomic fraction, demonstrating that the ET-NANB fragment is not an endogenous human or cynomolgus genomic fragment and additionally demonstrating that HEV is an RNA virus. Another confirmation of ET-NANB specific sequences in the fragments is the ability to express ET-NANB proteins from coding regions in the fragments and to demonstrated specific sero-reactivity of these proteins with sera collected during documented outbreaks of ET-NANB. Section IV below discusses methods of protein expression using the fragments.

One important use of the ET-NANB-specific fragments is for identifying ET-NANB-derived cDNAs which contain additional sequence information. The

newly identified cDNAs, in turn, yield new fragment probes, allowing further iterations until the entire viral genome is identified and sequenced. Procedures for identifying additional ET-NANB library clones and generating new probes therefrom generally follow the cloning and selection procedures described in Section II.

The fragments (and oligonucleotides prepared based on the sequences given above) are also useful as primers for a polymerase chain reaction method of detecting ET-NANB viral genomic material in a patient sample. This diagnostic method will be described in Section V below.

Two specific genetic sequences derived from the Mexican strain, identified herein as 406.3-2 and 406.4-2, have been identified that encode immunogenic epitopes. This was done by isolating clones which encode epitopes that immunologically react specifically with sera from individuals and experimental animals infected with HEV. Comparison of the isolated sequences with those in the Genebank collection of genetic sequences indicate that these viral sequences are novel. Since these sequences are unique, they can be used to identify the presence of HEV and to distinguish this strain of hepatitis from HAV, HBV, and HCV strains. The sequences are also useful for the design of oligonucleotide probes to diagnose the presence of virus in samples. They can be used for the synthesis of polypeptides that themselves are used in immunoassays. The specific

406.3-2 and 406.4-2 sequences can be incorporated into other genetic material, such as vectors, for ease of expression or replication. They can also be used (as demonstrated above) for identifying similar antigenic regions encoded by related viral strains, such as the Burmese strain.

IV. ET-NANB Proteins

As indicated above, ET-NANB proteins can be prepared by expressing open reading-frame coding regions in ET-NANB fragments. In one preferred approach, the ET-NANB fragments used for protein expression are derived from cloned cDNAs which have been treated to produce desired-size fragments, and preferably random fragments with sizes predominantly between about 100 to about 300 base pairs. Example 5 describes the preparation of such fragments by DNAs digestion. Because it is desired to obtain peptide antigens of between about 30 to about 100 amino acids, the digest fragments are preferably size fractionated, for example by gel electrophoresis, to select those in the approximately 100-300 basepair size range. Alternatively, cDNA libraries constructed directly from HEV-containing sources (e.g., bile or stool) can be screened directly if cloned into an appropriate expression vector (see below).

For example, the ET-NANB proteins expressed by the 406.3-2 and 406.4-2 sequences (and peptide fragments thereof) are particularly preferred since these proteins have been demonstrated to be immunoreactive with a variety of different human sera, thereby indicating the presence of one or more epitopes specific for HEV on their surfaces. These clones were identified by direct screening of a gtll library.

A. Expression Vector The ET-NANB fragments are inserted into a suitable expression vector. One exemplary expression vector is lambda gtll, which contains a unique EcoRI insertion site 53 base pairs upstream of the translation termination codon of the beta- galactosidase gene. Thus, the inserted sequence will be expressed as a beta-galactosidase fusion protein which contains the N-terminal portion of the beta- galactosidase gene, the heterologous peptide, and

optionally the C-terminal region of the beta- galactosidase peptide (the C-terminal portion being expressed when the heterologous peptide coding sequence does not contain a translation termination codon) . This vector also produces a temperature- sensitive repressor (cl857) which causes viral lysogeny at permissive temperatures, e.g., 32°C, and leads to viral lysis at elevated temperatures, e.g., 37°C. Advantages of this vector include: (1) highly efficient recombinant generation, (2) ability to select lysogenized host cells on the basis of host- cell growth at permissive, but not non-permissive, temperatures, and (3) high levels of recombinant fusion protein production. Further, since phage containing a heterologous insert produces an inactive beta-galactosidase enzyme, phage with inserts can be readily identified by a beta-galactosidase colored- substrate reaction.

For insertion into the expression vector, the viral digest fragments may be modified, if needed, to contain selected restriction-site linkers, such as EcoRI linkers, according to conventional procedures. Example 1 illustrates methods for cloning the digest fragments into lambda gtll, which includes the steps of blunt-ending the fragments, ligating with EcoRI linkers, and introducing the fragments into EcoRI-cut lambda gtll. The resulting viral genomic library may be checked to confirm that a relatively large (representative) library has been produced. This can be done, in the case of the lambda gtll vector, by infecting a suitable bacterial host, plating the bacteria, and examining the plaques for loss of beta- galactosidase activity. Using the procedures described in Example 1, about 50% of the plaques showed loss of enzyme activity.

B. Peptide Antigen Expression

The viral genomic library formed above is screened for production of peptide antigen (expressed as a fusion protein) which is immunoreactive with antiserum from ET-NANB seropositive individuals . In a preferred screening method, host cells infected with phage library vectors are plated, as above, and the plate is blotted with a nitrocellulose filter to transfer recombinant protein antigens produced by the cells onto the filter. The filter is then reacted with the ET-NANB antiserum, washed to remove unbound antibody, and reacted with reporter-labeled, anti- human antibody, which becomes bound to the filter, in sandwich fashion, through the anti-ET-NANB antibody.

Typically phage plaques which are identified by virtue of their production of recombinant antigen of interest are re-examined at a relatively low density for production of antibody-reactive fusion protein. Several recombinant phage clones which produced immunoreactive recombinant antigen were identified in the procedure.

The selected expression vectors may be used for scale-up production, for purposes of recombinant protein purification. Scale-up production is carried out using one of a variety of reported methods for (a) lysogenizing a suitable host, such as E^_ coli, with a selected lambda gtll recombinant (b) culturing the transduced cells under conditions that yield high levels of the heterologous peptide, and (c) purifying the recombinant antigen from the lysed cells. In one preferred method involving the above lambda gtll cloning vector, a high-producer E_^ coli host, BNN103, is infected with the selected library phage and replica plated on two plates. One of the plates is grown at 32°C, at which viral lysogeny can occur, and the other at 42°C, at which the infecting phage is in a lytic stage and therefore prevents cell growth. Cells which grow at the lower but not the

higher temperature are therefore assumed to be successfully lysogenized.

The lysogenized host cells are then grown under liquid culture conditions which favor high production of the fused protein containing the viral insert, and lysed by rapid freezing to release the desired fusion protein.

C. Peptide Purification The recombinant peptide can be purified by standard protein purification procedures which may include differential precipitation, molecular sieve chromatography, ion-exchange chromatography, isoelectric focusing, gel electrophoresis and affinity chromatography. In the case of a fused protein, such as the beta-galactosidase fused protein prepared as above, the protein isolation techniques which are used can be adapted from those used in isolation of the native protein. Thus, for isolation of a soluble betagalactosidase fusion protein, the protein can be isolated readily by simple affinity chromatography, by passing the cell lysis material over a solid support having surface-bound anti-beta- galactosidase antibody.

D. Viral Proteins

The ET-NANB protein of the invention may also be derived directly from the ET-NANB viral agent. VLPs or protein isolated from stool or liver samples from an infected individual, as above, are one suitable source of viral protein material. The VLPs isolated from the stool sample may be further purified by affinity chromatography prior to protein isolation (see below) . The viral agent may also be raised in cell culture, which provides a convenient and potentially concentrated source of viral protein. Co- owned U.S. Patent Application Serial No. 846,757, filed April 1, 1986, describes an immortalized trioma

liver cell which supports NANB infection in cell culture. The trioma cell line is prepared by fusing human liver cells with a mouse/human fusion partner selected for human chromosome stability. Cells containing the desired NANB viral agent can be identified by immunofluorescence methods, employing anti-ET-NANB human antibodies.

The viral agent is disrupted, prior to protein isolation, by conventional methods, which can include sonication, high- or low-salt conditions, or use of detergents.

Purification of ET-NANB viral protein can be carried out by affinity chromatography, using a purified anti-ET-NANB antibody attached according to standard methods to a suitable solid support. The antibody itself may be purified by affinity chromatography, where an immunoreactive recombinant ETNANB protein, such as described above, is attached to a solid support, for isolation of anti-ET-NANB antibodies from an immune serum source. The bound antibody is released from the support by standard methods.

Alternatively, the anti-ET-NANB antibody may be an antiserum or a monoclonal antibody (Mab) prepared by immunizing a mouse or other animal with recombinant ETNANB protein. For Mab production, lymphocytes are isolated from the animal and immortalized with a suitable fusion partner, and successful fusion products which react with the recombinant protein immunogen are selected. These in turn may be used in affinity purification procedures, described above, to obtain native ET-NANB antigen.

V. Utility Although ET-NANB is primarily of interest because of its effects on humans, recent data has shown that this virus is also capable of infecting other animals, especially mammals. Accordingly, any

discussion herein of utility applies to both human and veterinary uses, especially commercial veterinary uses, such as the diagnosis and treatment of pigs, cattle, sheep, horses, and other domesticated animals. A. Diagnostic Methods

The particles and antigens of the invention, as well as the genetic material, can be used in diagnostic assays. Methods for detecting the presence of ET-NANB hepatitis comprise analyzing a biological sample such as a blood sample, stool sample or liver biopsy specimen for the presence of an analyte associated with ET-NANB hepatitis virus.

The analyte can be a nucleotide sequence which hybridizes with a probe comprising a sequence of at least about 16 consecutive nucleotides, usually 30 to 200 nucleotides, up to substantially the full sequence of the sequences shown above (cDNA sequences). The analyte can be RNA or cDNA. The analyte is typically a virus particle suspected of being ET-NANB or a particle for which this classification is being ruled out. The virus particle can be further characterized as having an RNA viral genome comprising a sequence at least about 70% homologous to a sequence of at least 12 consecutive nucleotides of the "forward" and "reverse" sequences given above, usually at least about 80% homologous to at least about 60 consecutive nucleotides within the sequences, and may comprise a sequence substantially homologous to the full-length sequences. In order to detect an analyte, where the analyte hybridizes to a probe, the probe may contain a detectable label. Particularly preferred for use as a probe are sequences of consecutive nucleotides derived from the 406.3-2 and 406.4-2 clones described herein, since these clones appear to be particularly diagnostic for HEV.

The analyte can also comprise an antibody which recognizes an antigen, such as a cell surface

antigen, on a ET-NANB virus particle. The analyte can also be a ET-NANB viral antigen. Where the analyte is an antibody or an antigen, either a labelled antigen or antibody, respectively, can be used to bind to the analyte to form an immunological complex, which can then be detected by means of the label.

Typically, methods for detecting analytes such as surface antigens and/or whole particles are based on immunoassays. Immunoassays can be conducted either to determine the presence of antibodies in the host that have arisen from infection by ET-NANB hepatitis virus or by assays that directly determine the presence of virus particles or antigens. Such techniques are well known and need not be described here in detail. Examples include both heterogeneous and homogeneous immunoassay techniques. Both techniques are based on the formation of an immunological complex between the virus particle or its antigen and a corresponding specific antibody. Heterogeneous assays for viral antigens typically use a specific monoclonal or polydonal antibody bound to a solid surface. Sandwich assays are becoming increasingly popular. Homogeneous assays, which are carried out in solution without the presence of a solid phase, can also be used, for example by determining the difference in enzyme activity brought on by binding of free antibody to an enzyme-antigen conjugate. A number of suitable assays are disclosed in U.S. Patent Nos. 3,817,837, 4,006,360, 3,996,345. When assaying for the presence of antibodies induced by ET-NANB viruses, the viruses and antigens of the invention can be used as specific binding agents to detect either IgG or IgM antibodies. Since IgM antibodies are typically the first antibodies that appear during the course of an infection, when IgG synthesis may not yet have been initiated, specifically distinguishing between IgM and IgG antibodies present in the blood stream of a host will

enable a physician or other investigator to determine whether the infection is recent or convalescent. Proteins expressed by the 406.3-2 and 406.4-2 clones described herein and peptide fragments thereof are particularly preferred for use as specific binding agents to detect antibodies since they have been demonstrated to be reactive with a number of different human HEV sera. Further, they are reactive with both acute and convalescent sera. In one diagnostic configuration, test serum is reacted with a solid phase reagent having surface- bound ET-NANB protein antigen. After binding anti-ET- NANB antibody to the reagent and removing unbound serum components by washing, the reagent is reacted with reporter-labeled anti-human antibody to bind reporter to the reagent in proportion to the amount of bound anti-ET-NANB antibody on the solid support. The reagent is again washed to remove unbound labeled antibody, and the amount of reporter associated with the reagent is determined. Typically, the reporter is an enzyme which is detected by incubating the solid phase in the presence of a suitable fluorometric or colorimetric substrate.

The solid surface reagent in the above assay prepared by known techniques for attaching protein material to solid support material, such as polymeric beads, dip sticks, or filter material. These attachment methods generally include non-specific adsorption of the protein to the support or covaient attachment of the protein, typically through a free amine group, to a chemically reactive group on the solid support, such as an activate carboxyl, hydroxyl, or aldehyde group.

In a second diagnostic configuration, known as a homogeneous assay, antibody binding to a solid support produces some change in the reaction medium which can be directly detected in the medium. Known general types of homogeneous assays proposed

heretofore include (a) spin-labeled reporters, where antibody binding to the antigen is detected by a change in reported mobility (broadening of the spin splitting peaks), (b) fluorescent reporters, where binding is detected by a change in fluorescence efficiency, (c) enzyme reporters, where antibody binding effects enzyme/substrate interactions, and (d) liposome-bound reporters, where binding leads to liposome lysis and release of encapsulated reporter. The adaptation of these methods to the protein antigen of the present invention follows conventional methods for preparing homogeneous assay reagents.

In each of the assays described above, the assay method involves reacting the serum from a test individual with the protein antigen and examining the antigen for the presence of bound antibody. The examining may involve attaching a labeled anti-human antibody to the antibody being examined, either IgM (acute phase) or IgG (convalescent phase), and measuring the amount of reporter bound to the solid support, as in the first method, or may involve observing the effect of aϋstibody binding on a homogeneous assay reagent, as in the second method. Also forming part of the invention is an assay system or kit for carrying out the assay method just described. The kit generally includes a support with surface-bound recombinant protein antigen which is (a) immunoreactive with antibodies present in individuals infected with enterically transmitted nonA/nonB viral agent and (b) derived from a viral hepatitis agent whose genome contains a region which is homologous to the 1.33 kb DNA EcoRI insert present in plasmid pTZKFl(ET1.1) carried in E^ Coli strain BB4, and having ATCC deposit no. 67717. A reporter- labeled anti-human antibody in the kit is used for detecting surface-bound anti-ET-NANB antibody.

B. Viral Genome Diagnostic Applications

The genetic material of the invention can itself be used in numerous assays as probes for genetic material present in naturally occurring infections. One method for amplification of target nucleic acids, for later analysis by hybridization assays, is known as the polymerase chain reaction or PCR technique. The PCR technique can be applied to detecting virus particles of the invention in suspected pathological samples using oligonucleotide primers spaced apart from each other and based on the genetic sequence set forth above. The primers are complementary to opposite strands of a double stranded DNA molecule and are typically separated by from about 50 to 450 nt or more (usually not more than 2000 nt) . This method entails preparing the specific oligonucleotide primers and then repeated cycles of target DNA denaturation, primer binding, and extension with a DNA polymerase to obtain DNA fragments of the expected length based on the primer spacing. Extension products generated from one primer serve as additional target- sequences for the other primer. The degree of amplification of a target sequence is controlled by the number of cycles that are performed and is theoretically calculated by the simple formula 2^ where n is the number of cycles. Given that the average efficiency per cycle ranges from about 65% to 85%, 25 cycles produce from 0.3 to 4.8 million copies of the target sequence. The PCR method is described in a number of publications, including Saiki et al., Science (1985) 230:1350-1354; Saiki et al.. Nature (1986) 324:163-166; and Scharf et al., Science (1986) 233:1076-1078. Also see U.S. Patent Nos. 4,683,194; 4,683,195; and 4,683,202. The invention includes a specific diagnostic method for determination of ET-NANB viral agent, based on selective amplification of ET-NANB fragments. This method employs a pair of single-strand primers derived

from non-homologous regions of opposite strands of a DNA duplex fragment, which in turn is derived from an enterically transmitted viral hepatitis agent whose genome contains a region which is homologous to the 1.33 kb DNA EcoRI insert present in plasmid pTZKFl(ET1.1) carried in E_ _; _ coli strain BB4, and having ATCC deposit no. 67717. These "primer fragments," which form one aspect of the invention, are prepared from ET-NANB fragments such as described in Section III above. The method follows the process for amplifying selected nucleic acid sequences as disclosed in U.S. Patent No. 4,683,202, as discussed above.

C. Peptide Vaccine

Any of the antigens of the invention can be used in preparation of a vaccine. A preferred starting material for preparation of a vaccine is the particle antigen isolated from bile. The antigens are preferably initially recovered as intact particles as described above. However, it is also possible to pre¬ pare a suitable vaccine from particles isolated from other sources or non-particle recombinant antigens. When non-particle antigens are used (typically soluble antigens), proteins derived from the viral envelope or viral capsid are preferred for use in preparing vac¬ cines. These proteins can be purified by affinity chromatography, also described above.

If the purified protein is not immunogenic per se, it can be bound to a carrier to make the protein immunogenic. Carriers include bovine serum albumin, keyhole limpet hemocyanin and the like. It is desirable, but not necessary, to purify antigens to be substantially free of human protein. However, it is more important that the antigens be free of proteins, viruses, and other substances not of human origin that may have been introduced by way of, or contamination of, the nutrient medium, cell lines,

tissues, or pathological fluids from which the virus is cultured or obtained.

Vaccination can be conducted in conventional fashion. For example, the antigen, whether a viral particle or a protein, can be used in a suitable diluent such as water, saline, buffered salines, complete or incomplete adjuvants, and the like. The immunogen is administered using standard techniques for antibody induction, such as by subcutaneous administration of physiologically compatible, sterile solutions containing inactivated or attenuated virus particles or antigens. An immune response producing amount of virus particles is typically administered per vaccinizing injection, typically in a volume of one milliliter or less.

A specific example of a vaccine composition includes, in a pharmacologically acceptable adjuvant, a recombinant protein or protein mixture derived from an enterically transmitted nonA/nonB viral hepatitis agent whose genome contains a region which is homologous to the 1.33 kb DNA EcoRI insert present in plasmid pTZKFl(ET1.1) carried in E^ coli strain BB4, and having ATCC deposit no. 67717. The vaccine is administered at periodic intervals until a significant titer of anti-ET-NANB antibody is detected in the serum. The vaccine is intended to protect against ET¬ NANB infection.

Particularly preferred are vaccines prepared using proteins expressed by the 406.3-2 and 406.4-2 clones described herein and equivalents thereof, including fragments of the expressed proteins. Since these clones have already been demonstrated to be reactive with a variety of human HEV-positive sera, their utility in protecting against a variety of HEV strains is indicated.

D. Prophylactic and Therapeutic Antibodies and Antisera

In addition to use as a vaccine, the compositions can be used to prepare antibodies to ET¬ NANB virus particles. The antibodies can be used directly as antiviral agents. To prepare antibodies, a host animal is immunized using the virus particles or, as appropriate, non-particle antigens native to the virus particle are bound to a carrier as described above for vaccines. The host serum or plasma is collected following an appropriate time interval to provide a composition comprising antibodies reactive with the virus particle. The gamma globulin fraction or the IgG antibodies can be obtained, for example, by use of saturated ammonium sulfate or DEAE Sephadex, or other techniques known to those skilled in the art. The antibodies are substantially free of many of the adverse side effects which may be associated with other anti-viral agents such as drugs.

The antibody compositions can be made even more compatible with the host system by minimizing potential adverse immune system responses. This is accomplished by removing all or a portion of the FC portion of a foreign species antibody or using an antibody of the same species as the host animal, for example, the use of antibodies from human/human hybridomas.

The antibodies can also be used as a means of enhancing the immune response since antibody-virus complexes are recognized by macrophages. The anti¬ bodies can be administered in amounts similar to those used for other therapeutic administrations of anti¬ body. For example, pooled gamma globulin is admini¬ stered at 0.02-0.1 ml/lb body weight during the early incubation of other viral diseases such as rabies, measles and hepatitis B to interfere with viral entry into cells. Thus, antibodies reactive with the ET-NANB virus particle can be passively administered alone or in conjunction with another anti-viral agent to a host infected with an ET-NANB virus to enhance the immune

response and/or the effectiveness of an antiviral drug.

Alternatively, anti-ET-NANB-virus antibodies can be induced by administering anti-idiotype anti- bodies as immunogens. Conveniently, a purified anti— ET-NANB-virus antibody preparation prepared as de¬ scribed above is used to induce anti-idiotype antibody in a host animal. The composition is administered to the host animal in a suitable diluent. Following administration, usually repeated administration, the host produces anti-idiotype antibody. To eliminate an immunogenic response to the Fc region, antibodies pro¬ duced by the same species as the host animal can be used or the Fc region of the administered antibodies can be removed. Following induction of anti-idiotype antibody in the host animal, serum or plasma is removed to provide an antibody composition. The composition can be purified as described above for anti-ET-NANB virus antibodies, or by affinity chromatography using anti-ET-NANB-virus antibodies bound to the affinity matrix. The anti-idiotype antibodies produced are similar in conformation to the authentic ET-NANB antigen and may be used to prepare an ET-NANB vaccine rather than using a ET-NANB particle antigen.

When used as a means of inducing anti-ET- NANB virus antibodies in a patient, the manner of injecting the antibody is the same as for vaccination purposes, namely intramuscularly, intraperitoneally, subcutaneously or the like in an effective concentration in a physiologically suitable diluent with or without adjuvant. One or more booster injections may be desirable. The anti-idiotype method of induction of anti-ET-NANB virus antibodies can alleviate problems which may be caused by passive administration of anti-ET-NANB-virus antibodies, such as an adverse immune response, and those associated

with administration of purified blood components, such as infection with as yet undiscovered viruses.

The ET-NANB derived proteins of the invention are also intended for use in producing antiserum designed for pre- or post-exposure prophylaxis. Here an ET-NANB protein, or mixture of proteins is formulated with a suitable adjuvant and administered by injection to human volunteers, according to known methods for producing human antisera. Antibody response to the injected proteins is monitored, during a several- week period following immunization, by periodic serum sampling to detect the presence an anti-ET-NANB serum antibodies, as described in Section IIA above.

The antiserum from immunized individuals may be administered as a pre-exposure prophylactic measure for individuals who are at risk of contracting infection. The antiserum is also useful in treating an individual post-exposure, analogous to the use of high titer antiserum against hepatitis B virus for post- exposure prophylaxis.

E. Monoclonal Antibodies

For both in vivo use of antibodies to ET¬ NANB virus particles and proteins and anti-idiotype antibodies and diagnostic use, it may be preferable to use monoclonal antibodies. Monoclonal anti-virus particle antibodies or anti-idiotype antibodies can be produced as follows. The spleen or lymphocytes from an immunized animal are removed and immortalized or used to prepare hybridomas by methods known to those skilled in the art. To produce a human-human hybridoma, a human lymphocyte donor is selected. A donor known to be infected with a ET-NANB virus (where infection has been shown for example by the presence of anti-virus antibodies in the blood or by virus culture) may serve as a suitable lymphocyte donor. Lymphocytes can be isolated from a peripheral blood sample or spleen cells may be used if the donor is

subject to splenectomy. Epstein-Barr virus (EBV) can be used to immortalize human lymphocytes or a human fusion partner can be used to produce human-human hybridomas . Primary in vitro immunization with peptides can also be used in the generation of human monoclonal antibodies.

Antibodies secreted by the immortalized cells are screened to determine the clones that secrete antibodies of the desired specificity. For monoclonal anti-virus particle antibodies, the antibodies must bind to ET-NANB virus particles . For monoclonal anti-idiotype antibodies, the antibodies must bind to anti-virus particle antibodies. Cells producing antibodies of the desired specificity are selected.

The following examples illustrate various aspects of the invention, but are in no way intended to limit the scope thereof.

Material

The materials used in the following Examples were as follows:

Enzymes : DNAse I and alkaline phosphatase were obtained from Boehringer Mannheim Biochemicals (BMB, Indianapolis, IN); EcoRI, EcoRI methylase, DNA ligase, and DNA Polymerase I, from New England Biolabs

(NEB, Beverly MA); and RNase A was obtained from Sigma

(St. Louis, MO) .

Other reagents: EcoRI linkers were obtained from NEB; and nitro blue tetrazolium (NBT) , S-bromo-4- chloro-3-indolyl phosphate (BCIP) S-bromo-4-chloro-3- indolyl-B-D-galactopyranoside (Xgal) and isopropyl B-

D-thiogalactopyranσside (IPTG) were obtained from

Sigma. cDNA synthesis kit and random priming labeling kits are available from Boehringer-Mannheim

Biochemical (BMB, Indianapolis, IN).

Example 1_ Preparing cDNA Library A. Source of ET-NANB virus

Two cynomolgus monkeys (cynos) were intravenously injected with a 10% suspension of a stool pool obtained from a second-passage cyno (cyno #37) infected with a strain of ET-NANB virus isolated from Burma cases whose stools were positive for ET¬ NANB, as evidenced by binding of 27-34 nm virus-like particles (VLPs) in the stool to immune serum from a known ETNANB patient. The animals developed elevated levels of alanine aminotransferase (ALT) between 24-36 days after inoculation, and one excreted 27-34 nm VLPs in its bile in the pre-acute phase of infection. The bile duct of each infected animal was cannulated and about 1-3 cc of bile was collected daily. RNA was extracted from one bile specimen (cyno #121) by hot phenol extraction, using a standard RNA isolation procedure. Double-strand cDNA was formed from the isolated RNA by a random primer for first- strand generation, using a cDNA synthesis kit obtained from Boehringer-Mannheim (Indianapolis, IN).

B. Cloning the Duplex Fragments The duplex cDNA fragments were blunt-ended with T4 DNA polymerase under standard conditions (Maniatis, p. 118), then extracted with phenol/chloroform and precipitated with ethanol. The blunt-ended material was ligated with EcoRI linkers under standard conditions (Maniatis, pp. 396-397) and digested with EcoRI to remove redundant linker ends. Non-ligated linkers were removed by sequential isopropanol precipitation.

Lambda gtlO phage vector (Huynh) was obtained from Promega Biotec (Madison, WI). This cloning vector has a unique EcoRI cloning site in the phage Cl repressor gene. The cDNA fragments from above were introduced into the EcoRI site by mixing 0.5 -

1.0 μg EcoRI-cleaved gtlO, 0.5-3 μl of the above duplex fragments, 0.5 μl 10X ligation buffer, 0.5 μl ligase (200 units), and distilled water to 5 μl . The mixture was incubated overnight at 14°C, followed by in vitro packaging, according to standard methods (Maniatis, pp. 256-268).

The packaged phage were used to infect an E. coli hfl strain, such as strain HG415. Alternatively, E. coli, strain C600 hfl available from Promega Biotec, Madison, WI, could be used. The percentage of recombinant plaques obtained with insertion of the EcoRI-ended fragments was less than 5% by analysis of 20 random plaques.

The resultant cDNA library was plated and phage were eluted from the selection plates by addition of elution buffer. After DNA extraction from the phage, the DNA was digested with EcoRI to release the heterogeneous insert population, and the DNA fragments were fractionated on agarose to remove phage fragments. The 500-4,000 basepair inserts were isolated and recloned into lambda gtlO as above, and the packaged phage was used to infect E_^ coli strain HG415. The percentage of successful recombinants was greater than 95%. The phage library was plated on E_ _; _ coli strain HG415, at about 5,000 plaques/plate, on a total of 8 plates.

Example 2_ Selecting ET-NANB Cloned Fragments A. cDNA Probes

Duplex cDNA fragments from noninfected and ETNANB-infected cynomolgus monkeys were prepared as in Example 1. The cDNA fragments were radiolabeled by random priming, using a random-priming labeling kit obtained from Boehringer-Mannheim (Indianapolis, IN).

B. Clone Selection

The plated cDNA library from Example 1 was transferred to each of two nitrocellulose filters, and the phage DNA was fixed on the filters by baking, according to standard methods (Maniatis, pp. 320323). The duplicate filters were hybridized with either infected-source or control CDNA probes from above. Autoradiographs of the filters were examined to identify library clones which hybridized with radiolabeled CDNA probes from infected source only, i.e., did not hybridize with cDNA probes from the non- infected source. Sixteen such clones, out of a total of about 40,000 clones examined, were identified by this subtraction selection method.

Each of the sixteen clones was picked and replated at low concentration on an agar plate. The clones on each plate were transferred to two nitro¬ cellulose ag duplicate lifts, and examined for hybrid¬ ization to radiolabeled cDNA probes from infected and noninfected sources, as above. Clones were selected which showed selective binding for infected-source probes (i.e., binding with infected-source probes and substantially no binding with non-infected-source probes). One of the clones which bound selectively to probe from infected source was isolated for further study. The selected vector was identified as lambda gtlO-1.1, indicated in Figure 1.

Example _3 ET-NANB Sequence Clone lambda gtlO-l.l from Example 2 was digested with EcoRI to release the heterologous insert, which was separated from the vector fragments by gel electrophoresis. The electrophoretic mobility of the fragment was consistent with a 1.33 kb fragment. This fragment, which contained EcoRI ends, was inserted into the EcoRI site of a pTZKFl vector, whose construction and properties are described in co-owned U.S. patent application for "Cloning Vector System and

Method for Rare Clone Identification", Serial No. 125, 650, filed November 25, 1987. Briefly, and as illustrated in Figure 1, this plasmid contains a unique EcoRI site adjacent a T7 polymerase promoter site, and plasmid and phage origins of replication. The sequence immediately adjacent each side of the EcoRI site is known. E. coli BB4 bacteria, obtained from Stratagene (La Jolla, CA, were transformed with the plasmid. Radiolabeled ET-NANB probe was prepared by excising the 1.33 kb insert from the lambda gtlO-1.1 phage in Example 2, separating the fragment by gel electrophoresis, and randomly labeling as above. Bacteria transfected with the above pTZKFl and containing the desired ET-NANB insert were selected by replica lift and hybridization with the radiolabeled ET-NANB probe, according to methods outlined in Example 2.

One bacterial colony containing a successful recombinant was used for sequencing a portion of the 1.33 kb insert. This isolate, designated pTZKFl(ETl.1) , has been deposited with the American Type Culture Collection, and is identified by ATCC deposit no. 67717. Using a standard dideoxy sequencing procedure, and primers for the sequences flanking the EcoRI site, about 200-250 basepairs of sequence from the 5 '-end region and 3'-end region of the insert were obtained. The sequences are given above in Section II. Later sequencing by the same techniques gave the full sequence in both directions, also given above.

Example 4_ Detecting ET-NANB Sequences cDNA fragment mixtures from the bile of noninfected and ET-NANB-infected cynomolgus monkeys were prepared as above. The cDNA fragments obtained from human stool samples were prepared as follows.

Thirty ml of a 10% stool suspension obtained from an individual from Mexico diagnosed as infected with ET¬ NANB as a result of an ET-NANB outbreak, and a similar volume of stool from a healthy, non-infected individual, were layered over a 30% sucrose density gradient cushion, and centrifuged at 25,000 x g for 6 hr in an SW27 rotor, at 15°C. The pelleted material from the infected-source stool contained 27-34 nm VLP particles characteristic of ET-NANB infection in the infected-stool sample. RNA was isolated from the sucrose-gradient pellets in both the infected and non- infected samples, and the isolated RNA was used to produce cDNA fragments as described in Example 1.

The CDNA fragment mixtures from infected and non-infected bile source, and from infected and non- infected human-stool source were each amplified by a novel linker/primer replication method described in co-owned patent application serial number 07/208,512 for "DNA Amplification and Subtraction Technique," filed June 17, 1988. Briefly, the fragments in each sample were blunt-ended with DNA Pol I then extracted with phenol/chloroform and precipitated with ethanol. The blunt-ended material was ligated with linkers having the following sequence (top or 5' sequence has SEQ ID NO.21; bottom or 3'sequence has SEQ ID NO:22):

5'-GGAATTCGCGGCCGCTCG-3' 3'-TTCCTTAAGCGCCGGCGAGC-5'

The duplex fragments were digested with Nrul to remove linker dimers, mixed with a primer having the sequence 5'-GGAATTCGCGGCCGCTCG-3' , and then heat denatured and cooled to room temperature to form single-strand DNA/primer complexes. The complexes were replicated to form duplex fragments by addition of Thermus aquaticus (Taq) polymerase and all four deoxynucleotides. The replication procedures, involving successive strand denaturation, formation of

strand/primer complexes, and replication, was repeated 25 times.

The amplified cDNA sequences were fractionated by agarose gel electrophoresis, using a 2% agarose matrix. After transfer of the DNA fragments from the agarose gels to nitrocellulose paper, the filters were hybridized to a random-labeled 32p probe prepared by (i) treating the pTZKFl(ETl.1) plasmid from above with EcoRI, (ii) isolating the released 1.33 kb ET-NANB fragment, and (iii) randomly labeling the isolated fragment. The probe hybridization wag performed by conventional Southern blotting methods (Maniatis, pp. 382-389). Figure 2 shows the hybridization pattern obtained with cDNAs from infected (I) and non-infected (N) bile sources (2A) and from infected (I) and noninfected (N) human stool sources (2B). As seen, the ET-NANB probe hybridized with fragments obtained from both of the infected sources, but was non-homologous to sequences obtained from either of the non-infected sources, thus confirming the specificity of derived sequence.

Southern blots of the radiolabeled 1.33 kb fragment with genomic DNA fragments from both human and cynomolgus-monkey DNA were also prepared. No probe hybridization to either of the genomic fragment mixtures was observed, confirming that the ET-NANB sequence is exogenous to either human or cynomolgus genome.

Example J5

Expressing ET-NANB Proteins A. Preparing ET-NANB Coding Sequences

The pTZKFl(ET1.1) plasmid from Example 2 was digested with EcoRI to release the 1.33 kb ET-NANB insert which was purified from the linearized plasmid by gel electrophoresis. The purified fragment was suspended in a standard digest buffer (0.5M Tris HC1, ^' pH 7.5; 1 mg/ml BSA; lOmM MnC12) to a concentration of

about 1 mg/ml and digested with DNAse I at room temperature for about 5 minutes. These reaction conditions were determined from a prior calibration study, in which the incubation time required to produce predominantly 100-300 basepair fragments was determined. The material was extracted with phenol/chloroform before ethanol precipitation.

The fragments in the digest mixture were blunt-ended and ligated with EcoRI linkers as in Example 1. The resultant fragments were analyzed by electrophoresis (5-10V/cm) on 1.2% agarose gel, using PhiX174/HaeIII and lambda/HindiII size markers. The 100-300 bp fraction was eluted onto NA45 strips (Schleicher and Schuell), which were then placed into 1.5 ml microtubes with eluting solution (1 M NaCl, 50 mM arginine, pH 9.0), and incubated at 67°C for 30-60 minutes. The eluted DNA was phenol/chloroform extracted and then precipitated with two volumes of ethanol. The pellet was resuspended in 20 μl TE (0.01 M Tris HC1, pH 7.5, 0.001 M EDTA) .

B. Cloning in an Expression Vector

Lambda gtll phage vector (Huynh) was obtained from Promega Biotec (Madison, WI). This cloning vector has a unique EcoRI cloning site 53 base pairs upstream from the beta-galactosidase translation termination codon. The genomic fragments from above, provided either directly from coding sequences (Example 5) or after amplification of cDNA (Example 4), were introduced into the EcoRI site by mixing 0.5- 1.0 μg EcoRI-cleaved gtll, 0.3-3 μl of the above sized fragments, 0.5 /.l 10X ligation buffer (above), 0.5 μl ligase (200 units), and distilled water to 5 μl . The mixture was incubated overnight at 14°C, followed by in vitro packaging, according to standard methods (Maniatis, pp. 256-268).

The packaged phage were used to infect E. coli strain KM392, obtained from Dr. Kevin Moore, DNAX

(Palo Alto, CA) . Alternatively, E^ Coli strain Y1090, available from the American Type Culture Collection (ATCC #37197), could be used. The infected bacteria were plated and the resultant colonies were checked for loss of beta-galactosidase activity-(clear plaques) in the presence of X-gal using a standard X- gal substrate plaque assay method (Maniatis). About 50% of the phage plaques showed loss of beta- galactosidase enzyme activity (recombinants) .

C. Screening for ET-NANB Recombinant Proteins

ET-NANB convalescent antiserum was obtained from patients infected during documented ET-NANB outbreaks in Mexico, Borneo, Pakistan, Somalia, and Burma. The sera were immunoreactive with VLPs in stool specimens from each of several other patients with ET¬ NANB hepatitis.

A lawn of E_^ coli KM392 cells infected with about 104 pfu of the phage stock from above was prepared on a 150 mm plate and incubated, inverted, for 5-8 hours at 37°C The lawn was overlaid with a nitrocellulose sheet, causing transfer of expressed ETNANB recombinant protein from the plaques to the paper. The plate and filter were indexed for matching corresponding plate and filter positions.

The filter was washed twice in TBST buffer (10 mM Tris, pH 8.0, 150 mM NaCl, 0.05% Tween 20), blocked with AIB (TBST buffer with 1% gelatin), washed again in TBST, and incubated overnight after addition of antiserum (diluted to 1:50 in AIB, 12-15 ml/plate). The sheet was washed twice in TBST and then contacted with enzyme-labeled anti-human antibody to attach the labeled antibody at filter sites containing antigen recognized by the antiserum. After a final washing, the filter was developed in a substrate medium containing 33 μl NBT (50 mg/ml stock solution maintained at 4°C) mixed with 16 μl BCIP (50 mg/ml stock solution maintained at 4°C) in 5 ml of alkaline

phosphatase buffer (100 mM Tris, 9.5, 100 mM NaCl, 5 mM MgC12). Purple color appeared at points of antigen production, as recognized by the antiserum.

D. Screening Plating

The areas of antigen production determined in the previous step were replated at about 100-200 pfu on an 82 mm plate. The above steps, beginning with a 5-8 hour incubation, through NBT-BCIP development, were repeated in order to plaque purify phage secreting an antigen capable of reacting with the ET¬ NANB antibody. The identified plaques were picked and eluted in phage buffer (Maniatis, p. 443).

E. Epitope Identification

A series of subclones derived from the original pTZKFl (ET1.1) plasmid from Example 2 were isolated using the same techniques described above. Each of these five subclones were immunoreactive with a pool of anti-ET antisera noted in C. The subclones contained short sequences from the "reverse" sequence set forth previously. The beginning and ending points of the sequences in the subclones (relative to the full "reverse" sequence), are identified in the table below.

Since all of the gene sequences identified in the table must contain the coding sequence for the epitope, it is apparent that the coding sequence for the epitope falls in the region between nucleotide 594 (5'-end) and 643 (3'-end). Genetic sequences equivalent to and complementary to this relatively short sequence are therefore particularly preferred aspects of the present invention, as are peptides produced using this coding region.

A second series of clones identifying an altogether different epitope was isolated with only Mexican serum.

The coding system for this epitope falls between nucleotide 2 (S -end) and 101 (3 -end).

Genetic sequences related to this short sequence are therefore also preferred, as are peptides produced using this coding region.

Two particularly preferred subclones for use in preparing polypeptides containing epitopes specific for HEV are the 406.3-2 and 406.4-2 clones whose sequences are set forth above. These sequences were isolated from an amplified cDNA library derived from a

Mexican stool. Using the techniques described in this section, polypeptides expressed by these clones have been tested for immunoreactivity against a number of different human HEV-positive sera obtained from sources around the world. As shown in Table 3 below, 8 sera immunoreactive with the polypeptide expressed by the 406.4-2, and 6 sera immunoreacted with polypeptide expressed by the 406.3-2 clone.

For comparison, the Table also shows reactivity of the various human sera with the Y2 clone identified in Table 1 above. Only one of the sera reacted with the polypeptide expressed by this clone.

No immunoreactivity was seen for normal expression products of the gtll vector.

Table 3

Immunoreactivity of HEV Recombinant Proteins: Human Sera Sera Source Stagel 406.3-2 406.4-2 Y2 λgtll

+

+ + ND

1 = acute; C = convalescent

While the invention has been described with reference to particular embodiments, methods, construction and use, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the invention.