Maf as driver of exhaustion

Field of the Invention

The invention relates to a pharmaceutical composition comprising patient's empowered autologous CD8 T cells for use in a method for treating solid tumour cancers in said patient.

BACKGROUND OF THE INVENTION

The adaptive immune system plays a central, yet complex role in controlling tumor (tumour) growth. It can suppress tumors by destroying cancer cells or inhibiting their growth. It can also promote tumor progression either by selecting for tumor cells that are more fit to survive an immune attack or by establishing conditions within the tumor microenvironment that facilitate tumor outgrowth. Nevertheless the presence of CD8 T-cells associated with expression of effector molecules, like Granzyme B (GZMB) or perforin, inside primary tumors has been correlated with a better prognosis for patients affected with a wide variety of cancers. In spite of this, T-cells infiltrating tumors often share features with exhausted T-cells in chronic infection. The molecular bases characterizing this state have been thoroughly detailed in previous studies using LCMV and other viral chronic infections. In both cases CD8 T-cells express inhibitory receptors including PD-1, Lag-3 and CTLA-4. It is now well recognized that these receptors inhibit T-cell mediated protection from chronic infections and tumors. In particular, blockade of PD-1 has been shown to restore function in exhausted CD8 T-cells during chronic viral infection. Accordingly, the therapeutic use of "blocking" antibodies specific for CTLA-4, PD-1 and PD-L1 is increasingly useful for cancer patients. This approach represents a breakthrough for the treatment of patients with various solid tumors. However, except for inhibitory receptors, mechanisms that regulate tumor-induced T- cell exhaustion are poorly documented. While several transcription factors (T-bet, Blimp- 1 and Batf) have been shown to play a role in chronic infection, little is known concerning the establishment of T-cell exhaustion in cancer.

US 2014/0127268 (Sieweke, INSERM) relates to an ex vivo method for expanding

monocytes, macrophages or dendritic cells, which method comprises inhibiting the expression or the activity of MafB and c-Maf in monocytes, macrophages or dendritic cells; and expanding the cells in the presence of at least one cytokine or an agonist of cytokine receptor signalling. Myeloid cells (including monocytes, macrophages and dendritic cells) naturally express MafB and c-Maf however it is not the case for CD8 T lymphocytes.

T lymphocytes ("anti-tumor T cells") can eliminate cancer and chronic infections, provided that they are sufficiently "empowered" for robust and prolonged action against disease.

Naturally in patients, however, these T cells are frequently "exhausted", i.e. they are dysfunctional. SASCHA RUTZ et al: "Transcription factor c-Maf mediates the TGF-[beta]-dependent suppression of IL-22 production in TH17 cells", NATURE IMMUNOLOGY, Vol. 12, no. 12, 16 October 2011, pp 1238-1245, XP055220525, study the role of c-MAF in Thl7 CD4+ murine T cells. They inhibit c-MAF expression by using siRNA in vitro and stimulate the cells to obtain Thl7 CD4 T cells (with anti-CD3, anti-CD28, TGF-beta and IL-6). The cells obtained produce more IL-22, less IL-10 but remain Thl7-CD4 T cells with no cytotoxic potential and inefficient to target tumor cells. Furthermore Thl7 CD4 T cells are not associated with a good prognosis for cancer patients. Applicants do not use any IL-6 or TGF- beta that are potent inducers of c-MAF and that are inefficient to drive the expansion of cytolytic T cells.

A. IANNELLO et al.: "Dynamics and consequences of IL-21 production in HIV-infected individuals: A longitudinal and cross-sectional study", THE JOURNAL OF

IMMUNOLOGY, vol. 184, no. 1, 30 November 2009, pp 114-126, XP055220719, shows CD4 T cells coming from HIV+ patients lose their capacity to produce IL-21. They associate this defect with a gradual loss of c-MAF in the infected CD4+ T cells. To mimic the loss of c- MAF induced by the virus, they used siRNA that was transfected into the human CD4 T cells. They induced a partial reduction of c-MAF in those transfected cells that correlates with a decreased production of IL-21 and IL-4, which is detrimental for the anti-viral response. Those 2 cytokines are not required for anti-tumor T cell response.

X. MAO et al.: "A chemical biology screen identifies glucocorticoids that regulate c-maf expression by increasing its proteasomal degradation through up-regulation of ubiquitin", BLOOD, vol. 110, no. 12, 1 December 2007, pp 4047-4054, XP055220851, provides inhibitors for targeting myeloma cells to inhibit their proliferation.

Similarly, WO 2005/046731 Al (US GOV HEALTH & HUMAN SERV [US]; STAUDT L.) relates to a method for inhibiting the proliferation, survival and/or migration of a multiple myeloma cell that expresses (overexpresses) c-maf, comprising contacting the multiple myeloma cell with an effective amount of an inhibitor of expression and/or activity of c-maf, integrin 7 and/or cyclin D2. Also disclosed are methods for detecting multiple myeloma in a subject, and for treating multiple myeloma in a subject who has multiple myeloma cells that express c-maf. Also disclosed is a method for identifying an agent that inhibits the

proliferation of multiple myeloma cells that express c-maf, and/or inhibits the adhesion of the multiple myeloma cells to bone marrow stromal cells. This document is directed to inhibition in myeloma with the aim to stop myeloma proliferation. Giordano M et al: "The tumor necrosis factor alpha-induced protein 3 (TNFAIP3, A20) imposes a brake on antitumor activity of CD8 T cells"; PROCEEDINGS OF THE

NATIONAL ACADEMY OF SCIENCES, Vol. 111, no. 30, 14 July 2014, pp 11115-11120, XP055220839 discloses mechanisms controlling immune reactivity prevent excessive inflammation and autoimmunity, but generally dampen antitumor activity. The tumor necrosis factor alpha-induced protein 3 gene encoding the A20 protein, a key molecule controlling NF- KB activation, has been linked to the development of multiple inflammatory pathologies in humans, some of which are recapitulated in mice with selective deletion of A20 in myeloid, dendritic, or B cells. Here, mice with selective deletion of A20 in mature conventional T cells presented no detectable pathology. CD8 T cells from these mice showed increased antigen sensitivity with enhanced production of IL-2 and IFNy. Importantly, A20-deleted CD8 T cells possessed heightened antitumor activity in vivo. Thus this document shows that A20 causes dysfunction of melanoma specific CD8 T cells and its deletion in adoptively transferred CD8 T cells causes melanoma regression. Adoptive cell transfer therapy has shown some great success in treating patients with solid tumors, especially in the case of melanoma. It consists in harvesting T cells from a patient, amplify tumor specific T cells ex -vivo and, after reaching a high enough number of cells, transfer back these cells to the same patient. However, one major problem to solve to increase the efficiency of this therapy is to increase the survival and functions of the transferred cells in the patient and their resistance to the immunosuppressive environment created by the tumor. BRI EF DESCRI PTION OF THE I NVENTION

It is one goal of the present invention to solve this problem by inactivating the expression of the gene encoding for MAF before transferring the cells back in the patient. Applicants have surprisingly shown that Maf is a transcription factor that dampens survival and effector function of CD8 T cells during a response versus a tumor and that inactivating this gene in tumor specific CD8 T cells leads to an increased response toward a tumor and an increased survival of the cells in vivo.

Contrary to the teaching of US 2014/0127268 Applicants target c-Maf in CD8 T lymphocytes to increase survival and anti-tumor response in a protocol of adoptive immunotherapy.

Expression of c-Maf in CD8 T cells has never been established in vivo. Applicants showed for the first time that c-Maf is expressed in dysfunctional CD8 T cells infiltrated in tumors and that this expression prevents an efficient response of the CD8 T cells toward the tumor, i.e. its elimination.

Surprisingly one object of the invention is to inhibit c-MAF expression in CD8 T cells, as CD8 T cells infiltrated in tumors express high level of MAF, which was unknown till now. Those cytotoxic CD8 T cells are optimal to treat solid tumour cancer patient as they are highly cytotoxic, produce TNF-alpha and IFN-gamma.

In the prior art, the inhibition aims at different cell types (myeloma or CD4 T cells) without aiming at improving the capacity of the T cells to resist to immune-suppression and to have heightened capacity to destroy tumor cells.

In the present invention, cancer treatment, namely solid tumour cancer such as melanoma, is achieved through the adoptive transfer of tumour specific CD8 T cells in which c-maf expression or activity is abolished or inhibited. This is a totally new target taking into account that the Applicant's finding evidencing the role of c-maf as a major link in the chain of tumour specific T cell exhaustion was unknown. One of the objects of the present invention is to provide a pharmaceutical composition comprising patient's empowered autologous CD8 T cells; for use in an adoptive cell transfer method for treating solid tumor cancer in a patient in need thereof, wherein said empowered autologous CD8 T cells do not express c-Maf or in which the expression or activity of c-Maf is abolished or inhibited and whereas said autologous CD8 T cells are tumour-specific.

Another object of the present invention is to provide an ex vivo non therapeutic method for empowering a patient's autologous CD8 T cells originating from said patient's sample, characterized in that the method comprises:

ex vivo inhibiting the expression or the activity of c-Maf in said patient's autologous

CD8 T cells and

- expanding said autologous CD8 T cells to be suitable for a subsequent adoptive cell transfer to said patient,

wherein said patient's autologous CD8 T cells are tumour-specific and whereas said patient is suffering from a solid tumor cancer.

An object of the invention is also an empowered autologous CD8 T cell population obtainable by the above ex vivo method. Said empowered autologous CD8 T cells do not express c-Maf or their expression or activity of MafB and c-Maf is abolished or inhibited.

Such empowered autologous CD8 T cells are useful in a pharmaceutical composition, where they are in combination with a pharmaceutically acceptable carrier.

A yet further object is a kit to activate and amplify a patient's autologous CD8 T cells originating from said patient's sample, comprising:

a) means for abolishing or inhibiting the expression or activity of c-Maf in said

patient's autologous CD8 T cells, wherein said mean are inhibitors of the proto- oncogen c-maf selected among the group comprising c-Maf specific siRNA oligonucleotide, c-Maf specific antisense oligonucleotide, c-Maf specific shRNA oligonucleotide, c-Maf specific ribozymes oligonucleotide, c-Maf specific Zinc finger nuclease oligonucleotide, c-Maf specific TALENs oligonucleotide, c-Maf specific Crispr-Cas9 oligonucleotide sequences, dominant negative form of MAF; and b) pharmaceutically acceptable reagents and optionally comprising instructions to use,

wherein said patient's autologous CD8 T cells are tumour-specific and whereas said patient is suffering from a solid tumor cancer. Other objects and advantages of the invention will become apparent to those skilled in the art from a review of the ensuing detailed description, which proceeds with reference to the following illustrative drawings, and the attendant claims.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1: illustrates that Maf and nr4a2 are overexpressed in mouse and human CD8+ TILs.

(a) After the analysis of the microarrays, fold change between exhausted TILs (TILs) and naive (naive) CD8 T-cells and between exhausted TILs and activated (act) CD8 T-cells were calculated. Some genes of interest with a p-value lower than 0.05 in both conditions and a log ₂ fold change greater than 1 in both conditions are shown, (b) CD4 and CD8 T-cells were sorted from tumors of TiRP mice (3 independent samples). RNA levels for maf and nr4a2 from these cells (Exh) were compared to those from naive CD4 and CD8 T-cells by RT- QPCR. (c) Applicants compared by quantitative RT-PCR the level of Maf and Nr4a2 in Naive T cells isolated from Peripheral Blood Mononuclear Cells (PBMC) and Melan-A/MART-1 specific CD8 T cells from PBMC or metastasized LN (TILN) of melanoma patients.

Figure 2: shows the overexpression of maf, but not nr4a2, dampens the anti-tumor response by CD8 T-cells. (a-d) TCRPlA-luc CD8 T-cells were activated and transduced in- vitro with a retrovirus encoding either maf (maf) or nr4a2 (nr4a2) coupled to GFP expression or with a construct coding for GFP only (Mock). Two days after transduction, GFP- expressing CD8 T-cells were FACs sorted and 5.10 ⁴ of GFP+ TCRPlA-luc CD8 T-cells were injected in Rag ^~ B10.D2 mice, previously injected with 10 ⁶ P511 mastocytoma (7 days before), (a, b) P511 infiltration by TCRPlA-luc T-cells transduced with the indicated construct was monitored every 2-3 days by bioluminescence. (c) At day 7 post-transfer, percentages of TCRPIA CD8 T-cells among CD45+ cells (Mock- or maf-transduced) from draining LN (DLN), contralateral LN (CTLN), spleen and TILs from 2 pooled experiments were determined, (d) Tumor growth was monitored every 2-3 days using a caliper.

Figure 3: shows the overexpression of maf during anti-tumor response polarizes CD8 T- cells toward an exhausted phenotype. (a-e) TCRP1A CD8 T-cells were activated and transduced in-vitro with a retrovirus encoding either maf (maf - grey) coupled to GFP expression or with a construct encoding GFP only (Mock - black). Two days after transduction GFP-expressing CD8 T-cells were FACS-sorted and injected (5.10 ⁴ ) in Rag ^_/" B10.D2 mice, previously inoculated with 10 ⁶ P511 mastocytoma (7 days earlier). At day 7 post-transfer, mice were sacrificed. Cells from tumor draining LN (DLN), spleen or TILs were directly labeled (a) or restimulated and labeled (b) for the indicated molecules and analyzed by flow cytometry, (b) Numbers indicate the average of positive cells from 8 mice per condition from 2 independent experiments. Figure 4: illustrates the presence of TGFp or/and IL-6 during CD8 T-cell activation induces maf expression, (a) P14 T-cells were activated in-vitro with GP33 peptide (10 ^"6 M) in the presence of IL-6 (10 ng/ml) and/or TGFP (lOng/ml) for 72h. CD8 T cells were labelled with the indicated Ab and analyzed by flow cytometry. Levels of MAF in P14 T cells from maT-Cre+ maf™ mice (grey) or from Cre- littermates (black)(a) and average of the percentage of AnnexinV+ cells in the various conditions of culture (c) are shown. P14 T cell numbers were determined 72h post-stimulation and normalized according to the peptide only condition in 3 independent experiments (b). In (d) RNA from the two types of P14 T cells were analyzed by RT-QPCR. Pooled relative expressions compared to b2-microglobulin (ACt) for the indicated molecules and from 3 independent experiments are shown.

Figure 5: shows the inactivation of maf in tumor specific CD8 T cells increases tumor infiltration and elimination

C57B1/6 CD45.1+ mice were injected s.c with 0.3xl0 ⁵ B16-GP33 melanoma cells. One week after mice were adoptively transferred with 5.10 ⁶ in vitro pre-activated CD45.2+ P14 T cells from maT-Cre+ maf™ mice (8 mice - grey) or from Cre- littermates (8 mice - black) or left untreated (4 mice- dotted line). Tumor growth was assessed with a caliper every 2/3 days (a). In a similar experiment mice were sacrificed on the sixth day after transfer of P14 T cells. Percentage of CD45.1+ and CD45.2+ CD8 T cells was determined by FACs analysis, (b) Representative data from 4 mice per condition are shown. The same samples were re- stimulated for 6 hours with GP33 peptide and labelled with the indicated Ab. Pooled data from 4 mice per group are shown (c). Figure 6: shows that maf RNA level is increased in TILs isolated from transplanted melanoma, lymphoma and carcinoma.

Figure 7: illustrates methods to inhibit maf expression in mouse or human cells.

BRIEF DESCRIPTION OF THE SEQUENCES

SEQ ID NO: 1 corresponds to a 6384 nucleotides long DNA molecule coding for a human v- maf avian musculoaponeurotic fibrosarcoma oncogene homolog (maf) polypeptide.

SEQ ID NO: 2 corresponds to a 1122 nucleotides long DNA molecule coding for a human c- MAF polypeptide.

SEQ ID NO: 3 corresponds to a 6384 nucleotides long DNA molecule coding for a human c- MAF polypeptide.

SEQ ID NO: 4 corresponds to the protein sequence the human c-MAF.

SEQ ID NO: 5 corresponds to a 4450 nucleotides long DNA molecule coding for a human c- MAF polypeptide.

SEQ ID NO: 6 corresponds to a 812 nucleotides long DNA molecule coding for a human c- MAF polypeptide.

SEQ ID NO: 7 corresponds to a 6384 nucleotides long DNA molecule coding for a human c- MAF polypeptide.

SEQ ID NO: 8 corresponds to a 6360 nucleotides long DNA molecule coding for a mouse MAF polypeptide

SEQ ID NO: 9 to a 1113 nucleotides long DNA molecule coding for a mouse MAF polypeptide

SEQ ID NO: 10 corresponds to a 6360 nucleotides long DNA molecule coding for a mouse MAF polypeptide

SEQ ID NO: 11 corresponds to the protein sequence of the mouse c-MAF.

SEQ ID NO: 12 corresponds to a 4316 nucleotides long DNA molecule coding for a mouse

MAF polypeptide SEQ ID NO: 13 corresponds to a 931 nucleotides long DNA molecule coding for a mouse MAF polypeptide

SEQ ID NO: 14 corresponds to a 6360 nucleotides long DNA molecule coding for a mouse MAF polypeptide

SEQ ID NO: 15 corresponds to a DNA sequence of an artificial construct containing the mouse DNA coding for MAF polypeptide and the DNA coding for the green fluorescent protein (GFP)

SEQ ID NO: 16 corresponds to a DNA sequence of an artificial construct containing the mouse DNA coding for the NR4A2 polypeptide and the DNA coding for the green fluorescent protein (GFP)

SEQ ID NO: 17 corresponds to a nucleotide sequence homologous to a portion of the mouse DNA coding for the beta-2-microglubulin polypeptide

SEQ ID NO: 18 corresponds to a nucleotide sequence homologous to a portion of the mouse DNA coding for the beta-2-microglubulin polypeptide

SEQ ID NO: 19 corresponds to a nucleotide sequence homologous to a portion of the mouse DNA coding for the c-MAF polypeptide

SEQ ID NO: 20 corresponds to a nucleotide sequence homologous to a portion of the mouse DNA coding for the c-MAF polypeptide

SEQ ID NO: 21 corresponds to a nucleotide sequence homologous to a portion of the mouse DNA coding for the interleukin- 10 polypeptide

SEQ ID NO: 22 corresponds to a nucleotide sequence homologous to a portion of the mouse DNA coding for the interleukin- 10 polypeptide

SEQ ID NO: 23 corresponds to a nucleotide sequence homologous to a portion of the mouse DNA coding for the BCL6 polypeptide

SEQ ID NO: 24 corresponds to a nucleotide sequence homologous to a portion of the mouse DNA coding for the BCL6 polypeptide

SEQ ID NO: 25 corresponds to a nucleotide sequence homologous to a portion of the mouse DNA coding for the NR4A2 polypeptide

SEQ ID NO: 26 corresponds to a nucleotide sequence homologous to a portion of the mouse DNA coding for the NR4A2 polypeptide

SEQ ID NO: 27 corresponds to a nucleotide sequence homologous to a portion of the mouse DNA coding for the GZMB polypeptide SEQ ID NO: 28 corresponds to a nucleotide sequence homologous to a portion of the mouse DNA coding for the GZMB polypeptide

SEQ ID NO: 29 corresponds to a nucleotide sequence homologous to a portion of the human DNA coding for the GAPDH polypeptide

SEQ ID NO: 30 corresponds to a nucleotide sequence homologous to a portion of the human DNA coding for the GAPDH polypeptide

SEQ ID NO: 31 corresponds to a nucleotide sequence homologous to a portion of the human DNA coding for the c-MAF polypeptide

SEQ ID NO: 32 corresponds to a nucleotide sequence homologous to a portion of the human DNA coding for the c-MAF polypeptide

SEQ ID NO: 33 corresponds to a nucleotide sequence homologous to a portion of the human DNA coding for the NR4A2 polypeptide

SEQ ID NO: 34 corresponds to a nucleotide sequence homologous to a portion of the human DNA coding for the NR4A2 polypeptide

SEQ ID NO: 35 corresponds to the nucleotide sequence of Mus musculus:

acgcgtcgac aagcttcaga actggcaatg aacaattcc

SEQ ID NO: 36 corresponds to the nucleotide sequence of Mus musculus:

cgcggatcct ctagatcaca tgaaaaattc gggagaggaa gg

SEQ ID NO: 37 corresponds to the artificial nucleotide sequence:

tcggaaatat accaaagc

SEQ ID NO: 38 corresponds to the artificial nucleotide sequence:

ttttcctttt gcggccgctt ctttgacgtg cttgg

SEQ ID NO: 39 corresponds to the artificial protein sequence:

Leu Pro Tyr Leu Gly Trp Leu Val Phe

SEQ ID NO: 40 corresponds to the artificial protein sequence:

Lys Ala Val Tyr Asn Phe Ala Thr Cys

SEQ ID NO: 41 corresponds to a nucleotide sequence homologous to a portion of the human DNA coding for the c-MAF polypeptide

SEQ ID NO: 42 corresponds to a nucleotide sequence homologous to a portion of the firefly DNA coding for the luciferase polypeptide.

DETAILED DESCRIPTION OF THE INVENTION T lymphocytes ("anti-tumor T cells") can eliminate cancer and chronic infections, provided that they are sufficiently "empowered" for robust and prolonged action against disease. Naturally in patients, however, these T cells are frequently "exhausted", i.e. they are dysfunctional. To determine the reasons for exhaustion, Applicants analyzed their transcriptome in patients and in an especially designed mouse model. The T cells presented strong similarities with those described in chronic infection. However, notable differences appeared. Applicants focused their studies on the two transcriptional regulators with the highest fold increase in exhausted compared to naive CD8 T cells, nr4a2 and maf. While nr4a2 was highly expressed in both virus- and tumor-induced exhaustion, maf was highly over-expressed only in tumor-exhausted CD8 T cells. Anti-tumor CD8 T cells transduced to express maf showed dampened anti-tumor efficiency upon adoptive transfer. Maf-expressing CD8 T cells showed unaltered homeostasis but failed to accumulate in tumor-bearing hosts and developed defective anti-tumor secondary responses. Maf expression in CD8 T cells induced part of the transcriptional program associated with tumor-induced exhaustion. This included elevated expression of genes encoding inhibitory receptors (PD-1, GP49a), antiinflammatory proteins (IL-10, A20), negative regulators of chemokine receptors (Rgs-1, Rgs- 16), as well as transcription factors diverting CD8 T cells from a cytolytic program (Bcl6, Stat3). Surprisingly, the identified genes and the underlying mechanisms represent novel targets for novel therapies for improving immunotherapy against cancer.

Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described below. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. The publications and applications discussed herein are provided solely for their disclosure prior to the filing date of the present

application. Nothing herein is to be construed as an admission that the present invention is not entitled to antedate such publication by virtue of prior invention. In addition, the materials, methods, and examples are illustrative only and are not intended to be limiting. In the case of conflict, the present specification, including definitions, will control.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in art to which the subject matter herein belongs. As used herein, the following definitions are supplied in order to facilitate the understanding of the present invention.

The term "comprise" is generally used in the sense of include, that is to say permitting the presence of one or more features or components.

As used in the specification and claims, the singular forms "a", "an" and "the" include plural references unless the context clearly dictates otherwise. As used herein the terms "subject" or "patient" are well-recognized in the art, and, are used interchangeably herein to denotes a vertebrate, preferably a mammal, including dog, cat, rat, mouse, monkey, cow, horse, goat, sheep, pig, camel, and, most preferably, a human. In preferred embodiments, the subject is a subject in need of treatment or a subject with a disease or disorder namely diagnosed or suffering from a solid tumour cancer. The term does not denote a particular age or sex. Thus, adult and newborn subjects, whether male or female, are intended to be covered. Most preferably the CD8 T cells according to the composition or method of the invention are thus human cells.

In the context of the invention, the term "treating" or "treatment", as used herein, means reversing, alleviating, inhibiting the progress of, or preventing the disease or condition to which such term applies, or one or more symptoms of such disease or condition.

The term "an effective amount" refers to an amount necessary to obtain a physiological effect. The physiological effect may be achieved by one application dose or by repeated applications. The dosage administered may, of course, vary depending upon known factors, such as the physiological characteristics of the particular composition; the age, health and weight of the subject; the nature and extent of the symptoms; the kind of concurrent treatment; the frequency of treatment; and the effect desired and can be adjusted by a person skilled in the art.

The terms "nucleic acid," "polynucleotide," and "oligonucleotide" are used interchangeably and refer to a desoxyribonucleotide or ribonucleotide polymer, in linear or circular

conformation, and in either single- or double-stranded form. For the purposes of the present disclosure, these terms are not to be construed as limiting with respect to the length of a polymer. The terms can encompass known analogues of natural nucleotides, as well as nucleotides that are modified in the base, sugar and/or phosphate moieties (e.g.

phosphorothioate backbones). In general, an analogue of a particular nucleotide has the same base-pairing specificity; i.e., an analogue of A will base-pair with T.

The terms "polypeptide," "peptide" and "protein" are used interchangeably to refer to a polymer of amino acid residues. The term also applies to amino acid polymers in which one or more amino acids are chemical analogues or modified derivatives of a corresponding naturally-occurring amino acids.

"Recombination" refers to a process of exchange of genetic information between two polynucleotides. For the purposes of this disclosure, "homologous recombination (HR)" refers to the specialized form of such exchange that takes place, for example, during repair of double-strand breaks in cells via homology-directed repair mechanisms. This process requires nucleotide sequence homology, uses a "donor" molecule to template repair of a "target" molecule (i.e. the one that experienced the double-strand break), and is variously known as "non- crossover gene conversion" or "short tract gene conversion," because it leads to the transfer of genetic information from the donor to the target. Without wishing to be bound by any particular theory, such transfer can involve mismatch correction of heteroduplex DNA that forms between the broken target and the donor, and/or "synthesis-dependent strand annealing," in which the donor is used to resynthesize genetic information that will become part of the target, and/or related processes. Such specialized HR often results in an alteration of the sequence of the target molecule such that part or all of the sequence of the donor polynucleotide is incorporated into the target polynucleotide.

A "reporter gene" or "reporter sequence" refers to any sequence that produces a protein product that is easily measured, preferably although not necessarily in a routine assay.

Suitable reporter genes include, but are not limited to, sequences encoding proteins that mediate antibiotic resistance (e.g., ampicillin resistance, neomycin resistance, G418 resistance, puromycin resistance), sequences encoding colored or fluorescent or luminescent proteins (e.g., green fluorescent protein, enhanced green fluorescent protein, red fluorescent protein, luciferase), and proteins which mediate enhanced cell growth and/or gene amplification (e.g., dihydrofolate reductase). Epitope tags include, for example, one or more copies of FLAG, His, myc, Tap, HA or any detectable amino acid sequence. "Expression tags" include sequences that encode reporters that may be operably linked to a desired gene sequence in order to monitor expression of the gene of interest.

"The CRISPR" (Clustered Regularly Interspaced Short Palindromic Repeats)/Cas (CRISPR Associated) nuclease system is a recently engineered nuclease system based on a bacterial system that can be used for genome engineering. It is based on part of the adaptive immune response of many bacteria and archea. When a virus or plasmid invades a bacterium, segments of the invader's DNA are converted into CRISPR RNAs (crRNA) by the 'immune' response. This crRNA then associates, through a region of partial complementarity, with another type of RNA called tracrRNA to guide the Cas9 nuclease to a region homologous to the crRNA in the target DNA called a "protospacer." Cas9 cleaves the DNA to generate blunt ends at the DSB at sites specified by a 20-nucleotide guide sequence contained within the crRNA transcript. Cas9 requires both the crRNA and the tracrRNA for site specific DNA recognition and cleavage. This system has now been engineered such that the crRNA and tracrRNA can be combined into one molecule (the "single guide RNA"), and the crRNA equivalent portion of the single guide RNA can be engineered to guide the Cas9 nuclease to target any desired sequence (see Jineket al (2012) Science 337, p. 816-821, Jineket al, (2013), eLife 2:e00471, and David Segal, (2013) eLife 2:e00563). Thus, the CRISPR/Cas system can be engineered to create a DSB at a desired target in a genome, and repair of the DSB can be influenced by the use of repair inhibitors to cause an increase in error prone repair.

"Adoptive cell transfer" can refer to the transfer of cells, most commonly immune-derived cells, back into the same patient or into a new recipient host with the goal of transferring the immunologic functionality and characteristics into the new host. If possible, use of autologous cells helps the recipient by minimizing GVHD issues. For isolation of immune cells for adpotive transfer, a phlebotomist draws blood into tubes containing anticoagulant and the PBM (buffy coat) cells are isolated, typically by density barrier centrifugation. In CD8 T cell- based therapies, these cells are expanded in vitro using cell culture methods relying heavily on the immunomodulatory action of interleukin-2 and returned to the patient in large numbers intravenously in an activated state. The term "expression" when used in the context of expression of a gene or nucleic acid refers to the conversion of the information, contained in a gene, into a gene product. A gene product can be the direct transcriptional product of a gene (e.g., mRNA, tR A, rRNA, antisense RNA, ribozyme, structural RNA or any other type of RNA) or a protein produced by translation of a mRNA. Gene products also include messenger RNAs which are modified, by processes such as capping, polyadenylation, methylation, and editing, and proteins (e.g., MafB or c-Maf) modified by, for example, methylation, acetylation, phosphorylation, ubiquitination, SUMOylation, ADP-ribosylation, myristilation, and glycosylation. An "inhibitor of expression" refers to a natural or synthetic compound that reduces or suppresses the expression of a gene.

An "inhibitor of activity" has its general meaning in the art, and refers to a compound (natural or not) which has the capability of reducing or suppressing the activity of a protein.

The term "c-Maf denotes the c-Maf proto-onocogene, which is identical in sequence to the v- Maf oncogene of AS42 virus and can transform chicken embryo fibroblasts (Nishizawa et al. PNAS 1989). C-Maf and other Maf family members form homodimers and heterodimers with each other and with Fos and Jun, consistent with the known ability of the AP-1 proteins to pair with each other (Kerppola, T. K. and Curran, T. (1994) Oncogene 9:675-684; Kataoka, K. et al. (1994) Mol. Cell. Biol. 14:700-712). The DNA target sequence to which c-Maf homodimers bind, termed the c-Maf response element (MARE), is a 13 or 14 bp element which contains a core TRE (T-MARE) or CRE (C-MARE) palindrome respectively, but c- Maf may also bind to DNA sequences diverging from these consensus sites including composite AP-1/MARE sites and MARE half sites with 5' AT rich extensions (Yoshida et al., NAR2005).

By "purified" and "isolated" it is meant, when referring to a polypeptide or a nucleotide sequence, that the indicated molecule is present in the substantial absence of other biological macromolecules. When referring to a cell or a population of cells, the term means that said cell or said population of cells is present in the substantial absence of other cells or population of cells. The term "purified" as used herein preferably means at least 75% by weight or number, more preferably at least 85% by weight or number, still preferably at least 95% by weight or number, and most preferably at least 98% by weight or number, of biological macromolecules or cells of the same type are present. An "isolated" nucleic acid molecule, which encodes a particular polypeptide refers to a nucleic acid molecule which is substantially free of other nucleic acid molecules that do not encode the subject polypeptide; however, the molecule may include some additional bases or moieties which do not deleteriously affect the basic characteristics of the composition.

A "cytotoxic T cell" (also known as TC, cytotoxic T lymphocyte, CTL, T-killer cell, cytolytic T cell, CD8+ T-cells or killer T cell) is a T lymphocyte (a type of white blood cell) that kills cancer cells, cells that are infected (particularly with viruses), or cells that are damaged in other ways. Most cytotoxic T cells express T-cell receptors (TCRs) that can recognize a specific antigen. An "antigen" is a molecule capable of stimulating an immune response, and is often produced by cancer cells or viruses. Antigens inside a cell are bound to class I MHC molecules, and brought to the surface of the cell by the class I MHC molecule, where they can be recognized by the T cell. If the TCR is specific for that antigen, it binds to the complex of the class I MHC molecule and the antigen, and the T cell destroys the cell.

In order for the TCR to bind to the class I MHC molecule, the former must be accompanied by a glycoprotein called CD8, which binds to the constant portion of the class I MHC molecule. Therefore, these T cells are called CD8+ T cells.

"CD8 T cell" is a T cell with CD8 receptor that recognizes antigens on the surface of a virus- infected cell and binds to the infected cell and kill it.

The affinity between CD8 and the MHC molecule keeps the Tc cell and the target cell bound closely together during antigen-specific activation. CD8+ T cells are recognized as Tc cells once they become activated and are generally classified as having a pre-defined cytotoxic role within the immune system. However, CD8+ T cells also have the ability to makes

some cytokines.

T-cells infiltrating neoplasms express surface molecules typical of chronically virus- stimulated T-cells, often termed "exhausted" T-cells. Applicants compared the transcriptome of "exhausted" CD8 T-cells infiltrating autochthonous melanomas to those of naive and acutely stimulated CD8 T-cells. Despite strong similarities between transcriptional signatures of tumor- and virally-induced exhausted CD8 T-cells, notable differences appeared. Among transcriptional regulators, Nr4a2 and Maf were highly over-expressed in tumor-exhausted T- cells and significantly upregulated in CD8 T-cells from human melanoma metastases. Transduction of murine tumor-specific CD8 T-cells to express Maf partially reproduced the transcriptional program associated with tumor-induced exhaustion. Upon adoptive transfer, the transduced cells showed normal homeostasis but failed to accumulate in tumor-bearing hosts and developed defective anti-tumor secondary responses. Applicants further identified TGFP and IL-6 as main contributors to Maf expression in CD8 T-cells and showed that Maf- deleted tumor specific CD8 T-cells were much more potent to restrain tumor growth in vivo. Therefore the melanoma microenvironment contributes to skewing of CD8 T-cell differentiation programs, in part by TGFp/IL-6 mediated induction of Maf.

Applicants developed a mouse model of induced melanoma based on conditional deletion of tumor suppressor genes with concomitant expression of a natural mouse tumor antigen (TiRP mice) (Huijbers et al, 2006). In this model tumor-intrinsic factors control the development of aggressive tumors and their expression of an inflammatory/immunosuppressive program. Applicants showed that intra-tumor T-cells expressed high level of inhibitory receptors such as PD-1 and had poor capacity to produce interferon gamma (IFN-γ) upon restimulation, concluding that they were exhausted. Taking advantage of this model, Applicants established the gene expression signature associated with CD8 T-cell exhaustion during autochthonous melanoma development. Applicants show that tumor- and virus-induced exhaustion share many features, with expression of genes encoding molecules such as inhibitory receptors or particular transcription factors. Among the latter Nr4a2, encoding an orphan nuclear receptor, was highly expressed in both virus- and tumor-induced exhaustion, whereas Maf was highly over-expressed in tumor-exhausted CD8 T-cells and very weakly during chronic viral infection. Applicants confirmed the overexpression for both genes in Melan-A/MART-1 specific CD8 T-cells isolated from metastasized lymph nodes (LN) from melanoma patients. Over-expression of Maf ^" by retroviral transduction of CD8 T-cells dampened their intra-tumor accumulation and anti-tumor activity, while over-expression of Nr4a2 did not affect CD8 T- cell properties in the same assays. Surprisingly, Applicants showed that Maf expression in anti-tumor CD8 T-cells contributes to their polarization toward an exhausted phenotype. In addition, Applicants show that the presence of TGFP and IL-6 are capable of inducing Maf expression in CD8 T-cells in vitro and that a -depleted tumor specific CD8 T-cells have heightened capacity to eliminate melanoma cells in vivo. It is an object of the present invention to provide a pharmaceutical composition comprising empowered CD8 T cells, preferably patient's empowered autologous CD8 T cells, for use in an adoptive cell transfer method for treating solid tumor cancers in a patient in need thereof, wherein said empowered CD8 T cells, preferably said empowered autologous T cells, do not express c-Maf or in which the expression or activity of c-Maf is abolished or inhibited and whereas said autologous CD8 T cells are tumour-specific.

It is herein defined that the patient in need thereof is suffering and/or has been diagnosed from a solid tumor cancer. A "solid tumour" is an abnormal mass of tissue that usually does not contain cysts or liquid areas. Solid tumors may be benign (not cancer), or malignant also defined as solid tumour cancer". Different types of solid tumors are named for the type of cells that form them.

Examples of solid tumors are sarcomas, carcinomas, and lymphomas. Leukemias (cancers of the blood) generally do not form solid tumors.

In the scope of the invention, the solid tumor cancers include melanoma, sarcomas and carcinomas derived from lung, colon, stomach, brain, breast, uterus, ovary, prostate, bladder, pancreas and the head and neck region. In addition, hematological malignancies such as lymphomas can also be treated with the composition or method of the invention.

Preferably the solid tumor cancer is selected among the list of melanoma, sarcomas, lymphomas and carcinomas derived from lung, colon, stomach, brain, breast, liver, uterus, ovary, prostate, bladder, pancreas and the head and neck region.

More preferably, the solid tumor cancer is selected among the list of melanoma, lymphoma or colon adenocarcinoma. Even more preferably, the solid tumor cancer is a melanoma. Surprisingly, applicants have shown that the presence of either TGF-beta or IL-6 could induce the expression of maf in T cells. TGF-beta is produced in most human tumor type and blocking of its signaling show positive effect on the immune system in melanoma, lung cancer, breast cancer, pancreatic cancer, hepatocellular carcinoma, glioblastoma and glioma (Pickup et al 2013). Similarly 11-6 is produced in a wide variety of solid tumour cancers (prostate cancer, hepatic carcinoma, melanoma, myeloma, colon cancer, pancreatic cancer, lung cancer, glioblastoma and glioma) and has deleterious effect on the immune system (Bharti et al 2016). Therefore maf level is also increased in CD8 T cells infiltrated in other types of solid tumor cancers than melanoma. This has been shown for example in example 7, where applicants injected cells from 3 different cell lines (B16 melanoma, EL4 lymphoma, MC38 colon adenocarcinoma) in C57B1/6 mice.

Preferably the solid tumor cancer is a TGFP and/or IL-6 producing cancer and most preferably the cancer to be treated is a melanoma. In addition it has been shown that maf is induced when IL-6 or TGFP are produced in the tumor microenvironment.

The pharmaceutical composition of the invention is in combination with a pharmaceutically acceptable carrier. Such compositions comprise a therapeutically effective amount of a patient's empowered autologous T cells, preferably CD8 T cell, produced according to the invention, and a pharmaceutically acceptable carrier or excipient. By a "therapeutically effective amount" of patient's empowered autologous CD8T cells as above described is meant a sufficient amount of said empowered autologous CD8 T cell to treat a disease or disorder at a reasonable benefit/risk ratio applicable to any medical treatment. It will be understood, however, that the total daily usage of compositions of the present invention will be decided by the attending physician within the scope of sound medical judgment. The specific

therapeutically effective dose level for any particular patient will depend upon a variety of factors including the disorder being treated and the severity of the disorder; activity of the specific compound employed; the specific composition employed, the age, body weight, general health, sex and diet of the patient; the time of administration, route of administration, and rate of excretion of the specific compound employed; the duration of the treatment; drugs used in combination or coincidental with the specific cells employed; and like factors well known in the medical arts.

Pharmaceutically acceptable carrier or excipient includes but is not limited to saline, buffered saline, dextrose, water, glycerol and combinations thereof. The carrier and composition can be sterile. The formulation should suit the mode of administration. The composition, if desired, can also contain minor amounts of wetting or emulsifying agents, or pH buffering agents. The composition can be a liquid solution, suspension, or emulsion. In a preferred embodiment, the composition is formulated in accordance with routine procedures as a pharmaceutical composition adapted for intravenous administration to human beings. Typically, compositions for intravenous administration are solutions in sterile isotonic aqueous buffer. Where necessary, the composition may also include a solubilizing agent and a local anesthetic such as lignocaine to ease pain at the site of the injection. Inhibition of the expression or the activity of c-Maf may be achieved by any technique known to the skilled in the art. According to a preferred embodiment of the present invention, the expression or activity of c- Maf is abolished or inhibited by using inhibitors of the proto-oncogen c-maf selected among the group comprising c-Maf specific siR A oligonucleotide, c-Maf specific antisense oligonucleotide, c-Maf specific shR A oligonucleotide, c-Maf specific ribozymes oligonucleotide, c-Maf specific Zinc finger nuclease oligonucleotide, c-Maf specific TALENs oligonucleotide, c-Maf specific Crispr-Cas9 oligonucleotide sequences, dominant negative form of MAF. Other inhibitors of the proto-oncogen c-maf are chemical inhibitors of MAF. More preferably, inactivation of maf in CD8 T cells is carried out by Crispr-Cas9 technology or c-Maf specific shRNA oligonucleotide. For the sake of clarity, the following techniques are described as follows:

-Crispr-Cas9 technology:

this system uses a nuclease, CRISPR-associated (Cas9), that complexes with small RNAs as guides (gRNAs) to cleave DNA in a sequence-specific manner upstream of the protospacer adjacent motif (PAM) in any genomic location.

-TALENs:

TALENs are fusions of transcription activator-like (TAL) proteins and a Fokl nuclease. TAL proteins are composed of 33-34 amino acid repeating motifs with two variable positions that have a strong recognition for specific nucleotides. By assembling arrays of these TALs and fusing them to a Fokl nuclease, specific cutting of the genome can be achieved. When two TALENs bind and meet, the Fokl domains induce a double-strand break which can inactivate a gene, or can be used to insert DNA of interest.

-Zinc finger nuclease (ZFN) :

A ZFN is a hybrid molecule that couples the DNA binding domain of a zinc-finger protein with the DNA-cleaving nuclease domain of the restriction endonuclease Fokl. The DNA binding motif specified by the zinc fingers directs the ZFN to a specific (targeted) locus in the genome. A pair of ZFNs is required to cleave double-stranded DNA. Each ZFN recognizes a different 12-18 base pair target sequence, and these target sequences must be separated by 4-7 base pairs to allow formation of the catalytically active Fokl dimer. These positional constraints drive a very high degree of specificity.

-Ribozymes can also function as inhibitors of expression of c-Maf for use in the present invention. Ribozymes are enzymatic RNA molecules capable of catalyzing the specific cleavage of RNA. The mechanism of ribozyme action involves sequence specific

hybridization of the ribozyme molecule to complementary target RNA, followed by endonucleo lytic cleavage. Engineered hairpin or hammerhead motif ribozyme molecules that specifically and efficiently catalyze endonucleolytic cleavage of c-Maf mRNA sequences are thereby useful within the scope of the present invention. Specific ribozyme cleavage sites within any potential RNA target are initially identified by scanning the target molecule for ribozyme cleavage sites, which typically include the following sequences, GUA, GuU, and GUC. Once identified, short RNA sequences of between about 15 and 20 ribonucleotides corresponding to the region of the target gene containing the cleavage site can be evaluated for predicted structural features, such as secondary structure, that can render the

oligonucleotide sequence unsuitable. The suitability of candidate targets can also be evaluated by testing their accessibility to hybridization with complementary oligonucleotides, using, e.g., ribonuclease protection assays.

- siRNA:

siRNA is formed in the cell from shRNA or from long synthetic dsRNA by the Dicer enzyme, and is later separated into two short strands, one of which binds to the target mRNA and cleaves it, preventing the unwanted protein from being made. In the siRNA approach, specific siRNAs are synthesized in the laboratory to silence specific proteins in target cells which are implicated in disease.

-shRNA:

shRNA is short hairpin RNA, double stranded RNA (dsRNA) which is created in the cell from a DNA construct encoding a sequence of single stranded RNA and its complement, separated by a stuffer fragment, allowing the RNA molecule to fold back on itself, creating a dsRNA molecule with a hairpin loop. The target cell can be directed to produce shRNA by specific DNA sequences introduced to the cell via a small gene cassette which travels to the nucleus. Here the introduced DNA either becomes part of the cell's own DNA or persists in the nucleus, and instructs the cell to produce the specific shRNA, which is then processed by Dicer to siRNA and continues along the RNAi pathway via RISC to silence the gene.

-Dominant negative form of MAF: a dominant negative form of c-maf, termed Ac-maf, has been created by replacing the basic DNA binding region of c-maf with an acidic region while retaining the leucine zipper.

Retroviruses or lentiviruses can be used to transduce Ac-maf into cells.

-Chemical inhibitors of MAF (see Xialiang Mao et al, Blood ISSN 0006-4971, 2007 110: 4047-4054, "A chemical biology screen identifies glucocorticoids that regulate c-maf expression by increasing its proteosomal degradation through up-regulation of ubiquitin"): Some chemical inhibitors can increase the degradation of maf in cells.

In particular, the chemical inhibitors of MAF are identified as c-maf-dependent cyclin D2 inhibitors consisting of corticosteroid derivatives selected among the group comprising budesonide, flumethasone, betamethasone, diflorasone, flurandrenoline, flunisolide, methylprednisolone, prednisolone, triamcinolone, fluocinonide, isoflupredone acetate, dexamethasone acetate, corticosterone, fluorometholone, hydrocortisone base, halcinonide, prednicarbate, fludrocortisone acetate, clocortolone pivalate, alclometasone dipropionate, beclomethasone dipropionate, hydrocortisone, deoxycorticosterone, medrysone.

Preferably, the most potent chemical inhibitors of MAF are glucocorticoids such as dexamethasone acetate and dexamethasone.

Methods for delivering siRNAs, ribozymes and/or antisense oligonucleotides into CD8 T cells are well known in the art and include but are not limited to transfection, electroporation, microinjection, lipofection, calcium phosphate mediated transfection or infection with a viral vector containing the gene sequences, cell fusion, chromosome-mediated gene transfer, microcell-mediated gene transfer, spheroplast fusion, etc. Numerous techniques are known in the art for the introduction of foreign genes into cells and may be used in accordance with the present invention, provided that the necessary developmental and physiological functions of the recipient cells are not disrupted. The technique may provide for the stable transfer of the gene to the cell, so that the gene is expressible by the cell, heritable and expressible by its cell progeny. Usually, the method of transfer includes the transfer of a selectable marker to the cells. The cells are then placed under selection to isolate those cells that have taken up and are expressing the transferred gene. Those cells are then delivered to a subject. A variation of the technique may provide for transient transfer of oligonucleotides or oligonucleotide coding genes to T cells to enable temporary expansion of T cells ex vivo or in vivo without permanent genetic modification. Another object of the present invention is to provide an ex vivo and non-therapeutic method for empowering a patient's autologous CD8 T cells originating from said patient's sample such as patient's tumour or blood sample, the method comprises:

ex vivo inhibiting the expression or the activity of c-Maf in said patient's autologous CD8 T cells and,

- expanding said autologous CD8 T cells to be suitable for a subsequent adoptive cell transfer to said patient,

wherein said patient's autologous CD8 T cells are tumour-specific and whereas said patient is suffering from a solid tumor cancer.

Preferably the solid tumor cancer is selected among the list of melanoma, sarcomas, lymphomas and carcinomas derived from lung, colon, stomach, brain, breast, liver, uterus, ovary, prostate, bladder, pancreas and the head and neck region. More preferably the solid tumor cancer is selected among the list of melanoma, lymphoma or colon adenocarcinoma. Even most preferably, the solid tumor cancer is a melanoma.

In particular said patient's sample is a tumour sample or a blood sample.

Patient's CD8 T cells are tumour specific but circulate in the patient's body through the blood. Consequently blood samples can also be collected from the patient suffering and/or diagnosed from a solid tumor cancer. This procedure does not require a tumour biopsy on a cancer patient and thus a surgical step is not required to collect this type of patient's sample. Therefore patient's blood sample is preferred in the context of the present invention. It is acknowledged that the step of collecting patient's CD8 T cells is not part of the ex vivo method of the invention since this method for empowering a patient's autologous CD8 T cells is a non-therapeutic method.

For a sake of clarity, protocols to amplify the T cells from peripheral blood mononuclear cells (PBMCs) are well known to the skilled in the art. In particular, the sorting of 4- IBB high (a type 2 transmembrane glycoprotein belonging to the TNF superfamily, expressed on activated T Lymphocytes) or PD-1 high (Programmed cell death protein 1, also known as PD- 1 and CD279 (cluster of differentiation 279), is a protein that in humans is encoded by the PDCD1 gene. PD-1 is a cell surface receptor that belongs to the immunoglobulin superfamily and is expressed on T cells and pro-B cells) CD8 T cells is the main part. Then the amplification of T cells is exactly the same than for T cells coming from a solid tumor.

For example, amplification of tumor specific T cells from PBMCs of patients can be carried out as follows:

Cell sorting from PBMC requires that CD8+ cells are first enriched using magnetic beads. Enriched CD8 T cells are then labelled with fluorescent labelled antibodies and sorted using a flow cytometer. The cells are gated on live (PI negative), single cells, CD3+ and CD8+ cells, and on the population expressing high level of PD-1 or of 4-1BB depending on the protocols. Then sorted T cells are expanded in vitro using an excess of irradiated allogeneic feeder cells (5,000 rad) pooled from three donors in T cell medium supplemented with 30 ng/ml anti-CD3 and 3,000 IU of interleukin (IL)-2. After day 6, half of the medium is replaced with fresh T cell medium containing IL-2 every other day. At day 15, a second step of amplification starts, following similar protocols used for expansion of T cells obtained from tumors.

Selecting and expanding the empowered specific CD8 T cells "ex vivo" can circumvent some of the regulatory and tolerising effects of the tumour environment that are seen in active vaccination. In addition, CD8 T cells are manipulated "ex vivo" before adoptive transfer to enhance their numbers, specificity, and function.

In particular, the expression or activity of c-Maf is abolished or inhibited by using inhibitors of the proto-oncogen c-maf selected among the group comprising c-Maf specific siRNA oligonucleotide, c-Maf specific antisense oligonucleotide, c-Maf specific shRNA

oligonucleotide, c-Maf specific ribozymes oligonucleotide, c-Maf specific Zinc finger nuclease oligonucleotide, c-Maf specific TALENs oligonucleotide, c-Maf specific Crispr- Cas9 oligonucleotide sequences, dominant negative form of MAF. Other inhibitors of the proto-oncogen c-maf are chemical inhibitors of MAF.

More preferably, inactivation of maf in CD8 T cells is carried out by Crispr-Cas9 technology or c-Maf specific shRNA oligonucleotide.

The genes that Applicants newly identified can be manipulated in CD8 T cells from patients, making these CD8 T cells more powerful with regard to their anti-tumor activity. After "empowering" of the patient's ("autologous") CD8 T cells, they are transferred back to the patient in the so-called adoptive cell therapy, an approach that can be used for treating patients with metastatic cancer.

The present invention also provides for an empowered CD8 T cells preferably empowered autologous CD8 T cells, obtainable by the ex vivo method for empowering a patient's autologous CD8 T cells originating from said patient's tumour sample.

Said empowered autologous CD8 T cells, do not express c-Maf or their expression or activity of c-Maf is abolished or inhibited. Another aspect of the invention is to provide a kit to activate and amplify a patient's autologous CD8 T cells originating from said patient's sample, comprising:

c) means for abolishing or inhibiting the expression or activity of c-Maf in said

patient's autologous CD8 T cells, wherein said mean are inhibitors of the proto- oncogen c-maf selected among the group comprising c-Maf specific siRNA oligonucleotide, c-Maf specific antisense oligonucleotide, c-Maf specific shRNA oligonucleotide, c-Maf specific ribozymes oligonucleotide, c-Maf specific Zinc finger nuclease oligonucleotide, c-Maf specific TALENs oligonucleotide, c-Maf specific Crispr-Cas9 oligonucleotide sequences, dominant negative form of MAF; and

d) pharmaceutically acceptable reagents and optionally comprising instructions to use,

wherein said patient's autologous CD8 T cells are tumour-specific and in which said patient is suffering from a solid tumor cancer. Preferably the solid tumor cancer is selected among the list of melanoma, sarcomas, lymphomas and carcinomas derived from lung, colon, stomach, brain, breast, liver, uterus, ovary, prostate, bladder, pancreas and the head and neck region. More preferably the solid tumor cancer is selected among the list of melanoma, lymphoma or colon adenocarcinoma. Even most preferably, the solid tumor cancer is a melanoma.

In a preferred embodiment, the patient's sample is a tumour sample or a blood sample as disclosed above. Preferably the patient's sample is a blood sample previously collected from said patient suffering and/or diagnosed from a solid tumor cancer. Optionally, the kit comprises instructions for performing the method. The Kit of the invention may further comprise a support on which a cell can be propagated (e. g., a tissue culture vessel) or a support to which a reagent used in the method is immobilized. An element of a kit of the invention include pharmaceutically acceptable reagents such as suitable buffers, media components, or the like; a computer or computer- readable medium for storing and/or evaluating the assay results; logical instructions for practicing the methods described herein; logical instructions for analyzing and/or evaluating the assay results as generated by the methods herein; containers; or packaging materials. The reagents of the kit may be in containers in which the reagents are stable, e. g., in lyophilized form or stabilized liquids. The reagents may also be in single use form, e. g., in single dosage form for use as therapeutics, or in single reaction form for diagnostic use.

The Kit of the invention have many uses, which will be evident to the skilled worker. For example, they can be used in experiments to study factors involved in c-maf mediated activities, or to understand facets of the molecular pathogenesis of solid tumour cancers; to detect the presence of tumor infiltrated lymphocytes that express (overexpress) c-maf; to treat solid tumour cancers; to monitor the course of treatment of solid tumour cancers; or to identify inhibitory agents for use in the treatment of solid tumour cancers. An agent of interest can be characterized by performing assays with the kit, and comparing the results to those obtained with known agents (or by comparison to a reference database of the invention). Such assays are useful commercially, e. g., in high-throughput drug studies.

It is another object of the invention to provide for inhibitors of c-Maf expression in patient's autologous CD8 T cells for use in a method for treating solid tumour cancer in said patient, wherein said patient's CD8 T cells are ex vivo empowered by said inhibitors of c-Maf expression so as not to express c-Maf and whereas said empowered patient's CD8 T cells are suitable or to be used in adoptive cell transfer in said patient (cell therapy). More preferably said CD8 T cells are patient's autologous CD8 T cells.

Selecting and expanding the empowered specific CD8 T cells "ex vivo" can circumvent some of the regulatory and tolerising effects of the tumour environment that are seen in active vaccination. In addition, CD8 T cells are manipulated "ex vivo" before adoptive transfer to enhance their numbers, specificity, and function. Preferably said inhibitors of c-Maf are inhibitors of the proto-oncogen c-maf selected among the group comprising c-Maf specific siR A oligonucleotide, c-Maf specific antisense oligonucleotide, c-Maf specific shR A oligonucleotide, c-Maf specific ribozymes oligonucleotide, c-Maf specific Zinc finger nuclease oligonucleotide, c-Maf specific TALENs oligonucleotide, c-Maf specific Crispr-Cas9 oligonucleotide sequences, dominant negative form of MAF as well as chemical inhibitors of MAF.

More preferably, inactivation of maf in CD8 T cells is carried out by Crispr-Cas9 technology or c-Maf specific shRNA oligonucleotide.

Also encompassed by the present invention is a method of vaccinating an animal or a Human comprising administering the pharmaceutical composition of the invention which comprises empowered autologous CD8 T cells wherein said empowered autologous CD8 T cells do not express c-Maf or in which the expression or activity of c-Maf is abolished or inhibited and whereas said autologous CD8 T cells are tumour-specific. The pharmaceutical composition of the invention is to be administered in an amount effective for use as a vaccine.

Also provided is a method for the treatment of a solid tumour cancer selected from the group consisting of melanoma, sarcomas, lymphomas and carcinomas derived from lung, colon, stomach, brain, breast, liver, uterus, ovary, prostate, bladder, pancreas and the head or neck region comprising administration of the pharmaceutical composition of the invention which comprises empowered autologous CD8 T cells wherein said empowered autologous CD8 T cells do not express c-Maf or in which the expression or activity of c-Maf is abolished or inhibited and whereas said autologous CD8 T cells are tumour-specific.

As an example, the number of adoptively transferred empowered CD8 T cells can be optimized by one of skill in the art depending upon the response and overall physical health and characteristics of the individual patient. In one embodiment, such a dosage can range from about 10 ⁵ to about 10 ¹¹ cells per kilogram of body weight of the subject. In another embodiment, the dosage of empowered CD8 T cells is about 1.5 x 10 ⁵ cells per kilogram of body weight. In another embodiment, the dosage of empowered CD8 T cells is about 1.5 x 10 ⁶ cells per kilogram of body weight. In another embodiment, the dosage of empowered CD8 T cells is about 1.5 x 10 ⁷ cells per kilogram of body weight. In another embodiment, the dosage of empowered CD8 T cells is about 1.5 x 10 cells per kilogram of body weight. In another embodiment, the dosage of empowered CD8 T cells is about 1.5 x 10 ⁹ cells per kilogram of body weight. In another embodiment, the dosage of empowered CD8 T cells is about 1.5 x 10 ¹⁰ cells per kilogram of body weight. In another embodiment, the dosage of empowered CD8 T cells is about 1.5 x 10 ¹¹ cells per kilogram of body weight. Other dosages within these specified amounts are also encompassed by these methods (See, e.g., Dudley ME et al, 2002 Science 298, 850-4, and Porter et al, N Engl J Med. 2011 Aug 25;365(8):725-33).

It is also an object of the invention to provide for a method for regenerative medicine comprising administration of the pharmaceutical composition of the invention which comprises empowered autologous CD8 T cells wherein said empowered autologous CD8 T cells do not express c-Maf or in which the expression or activity of c-Maf is abolished or inhibited and whereas said autologous CD8 T cells are tumour-specific. Another aspect of the invention is a method for the screening of drugs comprising the use of the pharmaceutical composition of the invention which comprises empowered autologous CD8 T cells wherein said empowered autologous CD8 T cells do not express c-Maf or in which the expression or activity of c-Maf is abolished or inhibited and whereas said autologous CD8 T cells are tumour-specific.

Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is to be understood that the invention includes all such variations and modifications without departing from the spirit or essential characteristics thereof. The invention also includes all of the steps, features, compositions and compounds referred to or indicated in this specification, individually or collectively, and any and all combinations or any two or more of said steps or features. The present disclosure is therefore to be considered as in all aspects illustrated and not restrictive, the scope of the invention being indicated by the appended Claims, and all changes which come within the meaning and range of equivalency are intended to be embraced therein.

Various references are cited throughout this specification, each of which is incorporated herein by reference in its entirety. The foregoing description will be more fully understood with reference to the following

Examples. Such Examples, are, however, exemplary of methods of practising the present invention and are not intended to limit the scope of the invention.

Examples

Materials and methods: Mice and cell lines. TiRP-lOB; Ink4a/Arf flox/flox mice, "TiRP mice," were kept on a B10.D2 background and treated with 40H-tamoxifen as previously described. Mice heterozygous for the H-2L ^d /PlA ₃₅ -43-specific TCR-transgene (TCRP1A) (Shanker et al, 2007) were kept on the Rag-Γ B10.D2 background. Luciferase expressing TCRPIA mice (TCRPlA-luc) were generated as previously described. TCR transgenic P14 mice (TCR specific for the LCMV gp33 peptide and H-2D ^b ) with selective deletion of maf in mature T cells were obtained by crossing maf floxed/floxed mice with P14 maT-Cre mice (Giordano et al, 2014). Rag-1 ^/ B10.D2, C57BL/6 CD45.2 and C57BL/6 CD45.1 mice were also used. All these mice were bred in the CIML animal facility. Animal experiments respected French and European directives.

Cell preparation. CD8 T-cells were prepared from LN or spleen of TCRPIA Rag-l ^_/~ B10.D2 mice according to standard procedures. When prepared from immunocompetent B10.D2 mice, CD8 T-cells were enriched using Mouse CD8 negative selection kit (Dynal, Invitrogen) according to the manufacturer's instructions. For analysis of TILs, tumors were cut into small pieces and incubated with collagenase I for 45 minutes. Tumors were dispersed into a single cell suspension and passed over Ficoll-Paque™ solution (Amersham Biosciences AB).

CD8 T-cells activation and retroviral infections. Murine maf cDNA was amplified using the Stratagene Herculasell Kit (with the following primers: acgcgtcgacaagcttcagaactggcaatgaacaattcc / cgcggatcctctagatcacatgaaaaattcgggagaggaagg) and cloned into pRc/CMV-3X-Flag-GFP vector. FL cDNA vector encoding nr4a2 (IRCKp5014E0514Q) was obtained from ImaGenes GmbH. This cDNA was cloned into the retroviral vector pMX-IRES-GFP after PCR amplification using PFUultra HF (Agilent) using the following primers tcggaaatataccaaagc / ttttccttttgcggccgcttctttgacgtgcttgg. Retroviral particles were produced as previously described (Verdeil et al, 2006). TCRP1A T-cells were activated for 72h with 10 ^"7 M of PIA35-43 (LPYLGWLVF) peptide. 20h after initial stimulation, CD8 T-cells were retrovirally-transduced as previously described (Verdeil et al, 2006). Cultures were then continued for another 48h. P14 T CD8 T cells were stimulated with GP33 peptide (KAVYNFATC - 10 ^"6 M) for 48h before adoptive transfer experiments and up to 72h for in vitro analysis.

Flow cytometry. Antibodies were from BD Biosciences, except anti-GzniB mAb (Invitrogen) and anti-Maf mAb (eBiosciences). Cells (10 ⁶ ) were analyzed on a LSR2 UV or a LSR2 561 cytometer (BD Biosciences). Data were analyzed using Flow Jo (Treestar Inc., CA) or Diva (BD Biosciences) software. For intracellular cytokine staining, CD8 T-cells were stimulated ex-vivo for 4h with ionomycin (400ng/ml) and PMA (40ng/ml) in the presence of Golgi stop (BD) and permeabilized using the Cytofix/Cytoperm kit (BD Biosciences). For intracellular labelling with anti-Maf mAb, FoxP3 permeabilization buffer (eBiosciences) was used according to the manufacturer's protocol. Cells were labelled using Cell Trace Violet (life technologies) according to manufacturer's protocol.

Bioluminescence. The infiltration of the luciferase-expressing TCRP1A T-cells was monitored by bioluminescence imaging. After i.p. luciferin (3 mg/mouse) injection, the mice were anesthetized in a chamber flushed with a mixture of isofluorane (4% in air) and placed in the NightOwl LB981 (Berthold Technologies) under continuous anaesthetization as previously described (Shanker et al, 2007).

Transcriptome analyses. Naive CD8 T cells from lymph nodes of TCR transgenic TCRP1A B10.D2 mice were sorted by flow cytometry (CD8+, CD3+, CD44-, Topro3-). For AdPlA samples, naive CD8 T cells from lymph nodes of TCR transgenic TCRP1A B10.D2 (Ly5.2) were transferred into Ly5.1 B10.D2 mice. One day after adoptive transfer, mice were infected intra-dermally with the adenovirus AdPlAt (coding for PI A, the antigen recognized by TCRP1A CD8 T cells). Four days after infection draining lymph nodes were recovered and activated TCRP1A CD 8 T cells were sorted by flow cytometry (CD8+, Ly5.2+, CD44+, Topro3-). For TILs samples, 2 to 3 melanoma tumors from TIRP mice were pooled. After centrifugation on Ficoll-Paque™ solution (Amersham Biosciences AB), CD8 T cells were sorted by flow cytometry (CD3+, CD8+, Topro3-). Triplicates were used for Na ^' ive and AdPlA (activated) T cells. For TILs, T cells coming from 4 independent sortings (with 2 to 3 pooled tumors each time) were used. SuperAmp R A amplification was performed according to Miltenyi Biotec's undisclosed procedure and amplified cDNA labeled with Cy3 were hybridized on Agilent Whole Mouse Genome Oligo Microarrays 8 x 60K. Microarray data have been submitted to NCBI GEO database and are accessible with the following link: (http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE42824) . All the data were normalized by quantiles. The statistical analysis for detecting differentially expressed genes was made using LIMMA (Linear Model for Microarray Data) based on an empirical Bayes model. Probes whose maximal gene expression value did not exceed 5 (log ₂ scale) were removed. The remaining list contained 24 562 probes used for GSEA analysis. Genes with logFC >1 (or <-l) and p-value <0.05 were selected as regulated. All these selected genes were constituted as gene set for the subsequent GSEA analysis. To find GO terms that were overrepresented in exhausted T cells we used GOrilla (http://cbl-gorilla.cs.technion.ac.il/). Gene Ontology terms were summarized and visualized by using REVIGO (http ://revi go .irb .hr/).

GSEA Analysis. Data from GSE30431 were extracted from GEO. "CD8 D30 chronic" and "naive" samples were selected. Data were normalized by RMA. 21 938 probes were taken into account. Fold changes between CD8 D30 chronic" and "naive" samples were calculated and probes were ranked according to these ratios. All these selected genes were constituted as gene sets for the subsequent GSEA analysis.

Quantitative RT-PCR. Total RNA was isolated using RNeasy kit (Quiagen). RNA from sorted cell populations was reverse-transcribed using High Capacity cDNA Reverse Transcription Kit (Applied Biosystems). Quantitative real-time PCR was done by nonspecific detection (Power SYBR®Green, Applied Biosystems) of cDNA. For each gene, primer pairs generated a single product and were amplified in a linear relationship with the housekeeping beta-2-microglobulin gene.

Naive CD8 T cells and Melan-A/MART-1 specific T cells were sorted and processed as in (Baitsch et al, 2011).

Statistical analysis. Sample means were compared using Student's t test (2 tailed comparison) or multiple T Test using Sidak-Bonferoni method when multiple time points were compared. P-value is represented as following: P < 0.05 (*) P<0.01 (**), P<0.001 (***), P<0.0001 (****). Error bars display standard deviation.

Example 1:

Molecular characterization of T infiltrated lymphocytes (TILs) from autochthonous melanomas

To explore the molecular bases of tumor-induced exhaustion, Applicants performed a transcriptomic analysis of CD8 T-cells sorted by flow cytometry from autochthonous melanomas of TiRP mice. Applicants compared their profile with the transcriptomic profile of sorted naive CD44 low CD8 T-cells and of activated T Cell Receptor (TCR) transgenic CD8 T-cells (TCRPIA) obtained 4 days after infection with an adenovirus expressing PI A, the antigen recognized by the TCRPIA. Using a cut-off of a two-fold change in comparison to na ^' ive CD8 T-cells with a statistically significant p-value (p<0.05), 2192 known genes were found upregulated in activated CD8 T-cells versus 629 in CD8 TILs (hereafter also called exhausted T-cells) and 1630 were down regulated in activated CD8 T-cells versus 656 in exhausted CD8 T-cells. More than half of the genes upregulated in CD8 TILs (330) were also upregulated at similar levels in activated CD8 T-cells while about a third of the genes down regulated in CD8 TILs were also down regulated in activated CD8 T-cells.

Exhaustion has been associated with high level expression of inhibitory receptors that are normally transiently upregulated on effector T-cells but are rapidly down regulated when the pathogen is cleared. In the present setting Applicants confirmed that exhausted CD8 T- cells inside the melanomas expressed high level of PD-1 (Pdcdl), LAG-3 (Lag3), Tim-3 (Havcr2), GP49b (Lilrb4), NKG2A (Klrcl) and CTLA-4 (Ctla4) transcripts compared to na ^' ive CD8 T-cells. These transcripts were expressed at a higher (CTLA-4, GP49b), a similar (PD-1, NKG2A) or a lower (TIM-3, LAG-3) level in exhausted compared to activated CD8 T-cells.

Applicants then looked at genes specifically up- or down-regulated in exhausted CD8 T-cells compared to both na ^' ive and activated CD8 T-cells (Figure la). Applicants studied the enrichment of Gene Ontology terms associated with the genes from these two lists. The most represented group of genes with an upregulated expression consisted in "negative regulation of biological/cellular processes", followed by "homeostatic process and regulation of gene expression". Among the genes falling into the category of negative regulation, Applicants found genes encoding phosphatases like Ptpre and Ptprj, whose products regulate MAPK phosphorylation, a gene (Tnfaip3) encoding an inhibitor of the NF-κΒ pathway (Giordano et al, 2014), as well as genes encoding transcription factors (Nr4a2, Nr4a3, Maf NfatS). CD101, a surface molecule which inhibits TCR/CD3 phosphorylation in humans and expressed on highly suppressive regulatory T cells (Tregs) in mice, was also specifically expressed on exhausted CD8 T-cells. Lilrb4, encoding for the inhibitory receptor GP49 (ILT3), was also overexpressed on CD8+ TILs.

In summary the transcriptional signature of exhausted CD8 T-cells showed a high level of inhibitory receptors, with the expression of numerous genes involved in negative regulation of biological processes and in regulation of transcription as well as a strong downregulation of genes involved in metabolic processes.

Example 2: Nr4a2 and Maf are overexpressed in both mouse and human CD8 TILs

One aim of this study was to determine potential transcriptional regulators favoring exhaustion establishment in TILs. Applicants chose to focus studies on the two transcriptional regulators with the highest fold increase in exhausted CD8 T-cells compared to naive CD8 T- cells, Nr4a2 and Maf. Applicants validated the microarray data by measuring the level of expression of those two transcripts in CD8 and CD4 TILs obtained from TiRP melanomas and evaluated by flow cytometry the level of MAF in CD4 and CD8 T-cells in tumor free or TiRP mice. In the spleens of tumor free animals, Applicants found very few MAF+ CD8 T- cells (1.9%) and some MAF+ CD4 T-cells (around 10%; Figure la). In TiRP mice that had developed a tumor, the percentage of MAF+ CD4 T-cells was slightly increased in the spleen (17%) and was further raised in CD4 TILs (35.6%). MAF+ CD8 T-cells were only found among TILs, ranging from 6 to 42% of the CD8 TILs (average of 22%).

Applicants then determined whether the findings in a melanoma mouse model was applicable to humans. Therefore, Applicants used RNA from sorted na ^' ive T cells (CD8+, CD45RA+, CCR7+, CD27+, CD28+) from healthy donors and from Melan- A/MART- 1 specific CD8 T- cells isolated from the blood or from metastasized LNs of melanoma patients as previously described (Baitsch et al, 2011). Applicants measured the relative level of MAF and NR4A2 in those samples. For both genes, Applicants found a significant increase in tumor infiltrated CD8 T-cells compered to na ^' ive T-cells, with an average of a 25 and a 4 fold increase compared to the median value obtained in naive T-cells, for MAF and NR4A2 respectively (Figure lb). Blood derived Melan-A/MART-1 specific CD8 T-cells showed an intermediate level of expression for MAF (7 fold increase compared to Naive T-cells) and a level of NR4A2 expression that was similar to that of Naive T-cells.

These results validate the transcriptomic data for CD8 T-cells and show that there is convergence of gene expression in both CD4 and CD8 TILs in mouse and between human and mouse CD8 TILs, at least for the expression of Nr4a2 and Maf.

Example 3:

Overexpression of Maf dampens CD8 T-cell anti-tumor response

Applicants further focused our study on the effects of Nr4a2 and Maf expression in CD8 T- cells. To test whether forced expression of the transcription factors in CD8 T-cells would dampen their anti-tumor efficiency, Applicants needed to use a tumor model in which untransduced CD8 T-cells were able to induce tumor regression. This was not the case in the TiRP mouse model. Applicants therefore took advantage of a model using the P511 mastocytoma naturally expressing the PlA-encoded antigen. In this model as few as 10 ⁴ naive tumor specific CD8 T-cells were capable of inducing a strong but transient regression of the tumor burden. Applicants hypothesized that if their gene of interest played a role in the establishment/maintenance of a dysfunctional state in tumor infiltrating CD8 T-cells, their expression would dampen the anti-tumor response. Rag-/-B10.D2 mice were injected subcutaneously with P511 cells. One week later, pre-activated T-cells expressing a transgenic TCR recognizing the PlA-encoded Ag (TCRP1A T-cells) were adoptively transferred into the animals. Tumors reach their maximum size 7 days after the T-cell transfer and generally shrink and disappear 15 days after transfer (Figure 2d). Applicants used TCRP1A T-cells that are also transgenic for the luciferase encoding gene (TCRPlA-luc) to follow the accumulation of T-cells inside the tumor. TCRPlA-luc cells were activated in vitro and transduced with retroviruses encoding Maf and green fluorescent protein (gfp) (maf), Nr4a2 and gfp (nr4a2) or gfp alone (mock). After 3 days, T-cells were FACS sorted according to their expression of GFP. GFP ^hlgh TCRPlA-luc T-cells were transferred into tumor bearing mice. Applicants monitored by bioluminescence the infiltration of the tumors by the TCRPlA-luc T-cells (Figure 2a, b). Photon emission measured in the tumors showed no difference when TCRP1A T-cells were transduced with nr4a2 compared to mock (Figure 2a). However, Applicants detected a much lower signal for maf-transduced as compared to mock-transduced TCRPIA- luc T-cells (Figure 2b). This shows a strong decrease in intra-tumor accumulation of Maf- overexpressing CD8 T-cells. This was confirmed by determining the proportion of GFP+ maf-transduced TCRP1A T-cells at day 7, which was much lower in LN, spleen and tumor compared to their mock-transduced counterparts (Figure 2c). The overall tumor regression induced by adoptively transferred T-cells was also less pronounced for maf-transduced as compared to mock-transduced TCRP1A T-cells, whereas nr4a2 -transduced TCRP1A T-cells were as effective as their control counterparts (Figure 2d). Tumor shrinking was delayed for 5 days when maf-transduced as compared to mock-transduced T-cells were used in the adoptive transfer and the tumor never totally disappeared from the animal (Figure 2d).

Altogether the results presented here illustrate that maf-expressing CD8 T-cells were unaltered in their homeostasis, at least up to 7 days post-transfer in non-tumor bearing hosts, but developed a defective tumor-induced secondary response as compared to control T-cells and failed to accumulate in tumor-bearing hosts.

Example 4:

Overexpression of maf polarizes CD8 T-cell differentiation toward an exhausted phenotype.

To determine how maf expression influences the T-cell anti-tumor response, Applicants analyzed by flow cytometry TCRP1A T-cells ex-vivo (from LN, spleen or TILs), 7 days after transfer into P511 bearing mice. Maf-transduced GFP+ CD8 T-cells expressed a higher level of PD-1 and a lower level of GzmB compared to mock-transduced T-cells (Figure 3a). To test if the functional capacities of these cells were further affected, Applicants stimulated the cells from the tumor draining LN with PMA/Ionomycine ex-vivo. Clearly fewer maf-transduced than mock-transduced CD8 T-cells produced IFNy (9.7 compared to 23.7%) and IL-2 (0.83 compared to 4.1%) (Figure 3b).

Example 5: TG ? and IL-6 induce Maf expression in CD8 T-cells

In CD4 T-cells Maf expression has been associated to Th2, Thl7, Trl and follicular helper T-cells (Tfh) differentiation in response to TCR signaling plus various stimuli including the presence of cytokines like IL-4, IL-6, TGFP or IL-27 among others. However, scant information exists on the control of Maf expression in CD8 T-cells. In the TiRP model, the tumor itself produces high level of TGFp, IL-6 and IL-10(Soudja et al, 2010; Wehbe et al, 2012). Applicants tested if one of these cytokines could induce Maf expression during CD8 T- cell in vitro activation. We never detected MAF by flow cytometry or at the R A level after stimulation of TCR transgenic T cells without additional cytokines (Figure 4a). At day 3 post- activation, Applicants observed a strong increase in MAF+ population in the presence of TGFb, IL-6 or a combination of both (from 5 to 20% of the CD8 T-cells depending on the cytokine - Figure 4a). Altogether these data show that TGFP and IL-6 in the tumor microenvironment contribute to the induction of Maf expression in exhausted CD8 T-cells.

Example 6:

Maf deletion in CD8 T-cells dampens the effects of TG ? and IL-6 on their activation program- To further characterize the importance of MAF expression during the response of CD8 T-cells to antigenic stimulation, Applicants generated TCR transgenic P14 mice (TCR specific for the LCMV gp33 peptide and H-2D ^b ) with selective deletion of maf ^' in mature T cells by crossing maf floxed/floxed mice with P14 maT-Cre mice (Giordano et al, 2014) (PI 4 maT-Cre-maf ^fl/fl mice). Applicants evaluated the capacity of maf deficient CD8 T-cells to respond to stimulation with GP33 peptide in vitro in the presence of TGFb or/and IL-6. Stimulation with the cognate peptide recognized by the transgenic TCR can be replaced with stimulation with anti-CD3 and anti-CD28 with similar results. When stimulated with peptide alone, Applicants did not detect noticeable differences between Wild Type (WT) and maf deficient CD8 T-cells 3 days post-stimulation with regard to cell number or AnnexinV labeling (Fig.4 b, c). Maf deficient T-cells were however producing more IL-2 and ifng than their WT counterparts. Presence of 10 ng/ml TGFP in the culture medium dampened CD8 T-cell stimulation, affecting cell number but not their survival (Figure 5b, c). All of the effector functions were dampened in this condition: production of IL-2, expression of ifng and gzmb (Figure 4d). On the opposite Applicants detected a significant increase in MO and bcl6 expression (Figure 4d). In the maf deficient CD8 T-cells the proliferation was partially rescued as well as IL-2 production. The increased expression of bcl6 and MO in WT P14 T-cells in the presence of either TGFb or IL-6 was not detectable in the maf-deleted CD8 T-cells (Figure 4d). The presence of 10 ng/ml IL-6 did not affect cell proliferation in either WT or maf-deficient CD8 T-cells. The number of recovered cells was however increased by twofold for the maf- deficient CD8 T-cells (Figure 4b). This correlates with a decreased labeling with AnnexinV, suggesting a better survival of the maf-deficient cells in the presence of IL-6 (Figure 4c). IL-6 induced the expression of bcl-6, but not il-10, abrogated the expression of ifng and partially decreased the expression of gzmb in WT cells (Figure 4d). In maf-deficient CD8 T-cells IL-6 failed to induce expression of bcl6 and gzmb expression was partially restored. When IL-6 and TGFP were combined, their effects on WT T cells were more dramatic with decreased proliferation, increased apoptosis, high level of bcl6, MO and decreased level of ifng and IL-2 production (Figure 4b, c, d). Maf deletion strongly restored IL-2 production, cell survival and proliferation (Figure 4c), decreased bcl6 and MO expression but failed to restore significant levels of ifng or gzmb (Figure 4d). Altogether these data show that the effects of TGFP and IL-6 on CD8 T-cell activation are partially regulated by their induction of MAF in CD8 T- cells. Example 7:

CD8 T cells from multiple tumor types express high level of maf

As shown in Figure 6, C57B1/6 mice were injected s.c with 0.5xl0 ⁵ B16 melanoma cells, EL4 lymphoma cells or MC38 carcinoma cells. Two week after injection tumor were removed, cut in small pieces, digested with DNasel and collagenase for 30 minutes, mechanically disrupted and filtered to obtain a cell suspension. Cell suspensions were labelled with antibodies targeting CD3, CD8, CD45 and with topro-3 to label dead cells. Similar process was used to isolated CD8 T cells from the draining LN of these mice. CD45+ CD3+ CD8+ Topro-3- cells were sorted using flow cytometry. RNA isolated from those cells was used to perform quantitative PCR after reverse transcription to measure the level of the RNA encoding for maf relative to the expression of beta-2-microglobulin. Average of the level of maf in CD8 T cells isolated from mice transplanted with the 3 types of tumor is shown (LN; n=8). Level of maf in TILs for each individual cell line (Tils B16 (n=3), Tils EL4 (n=3) and Tils MC38 (n=2)) is shown.

Applicants have shown that the presence of either TGF-beta or IL-6 could induce the expression of maf in T cells. TGF-beta is produced in most human tumor type and blocking of its signaling show positive effect on the immune system in melanoma, lung cancer, breast cancer, pancreatic cancer, hepatocellular carcinoma, head and neck cancer, ovary cancer, glioblastoma and glioma (Pickup et al 2013; Prat J et al 2014 Curry JM et al 2014). Similarly 11-6 is produced in a wide variety of solid cancers (prostate cancer, hepatic carcinoma, melanoma, myeloma, colon cancer, pancreatic cancer, lung cancer, bladder cancer, glioblastoma and glioma) and has deleterious effect on the immune system (Bharti et al 2016) (yeh et al 2015). Therefore maf level should also be increased in CD8 T cells infiltrated in other types of solid cancers than melanoma. To test this hypothesis applicants injected cells from 3 different cell lines (B16 melanoma, EL4 lymphoma, MC38 colon adenocarcinoma) in C57B1/6 mice. After 2 weeks tumor were removed, cut in small pieces, digested with a cocktail of collagenase I and DNase I and mononuclear cells were enriched on a ficoll gradient. The cell suspension was labelled with antibodies for CD3, CD8 and a viability die. CD8 T cells were sorted by flow cytometry. A similar process was applied to CD8 T cells from the draining lymph node. R A from those cells were extracted and used to achieve quantitative RT-PCR to determine the level of maf in each cell type. Level of maf were two to three times higher in tumor infiltrated CD 8 T cells compared to the level determine in the LN. This shows that maf overexpression in tumor infiltrated T cells is not only a feature observed in melanoma but is also observed in other solid cancer models.

Example 8: Maf deletion in tumor specific CD8 T-cells increases their capacity to eliminate melanoma cells in vivo

Applicants next evaluated the capacity of adoptively transferred maf-deficient tumor specific CD8 T-cells to induce melanoma regression. Because of the C57BL/6 background of P14 maT-Cre maf* ¹⁷ * ¹ mice, Applicants had to use a different melanoma model. C57BL/6 (CD45.1) mice were injected s.c with B16F10 melanoma cells expressing the LCMV GP33 epitope (B16-GP33). One week later, WT or maf-deficient in vitro pre-activated P14 T-cells (on a C57BL/6 (CD45.2) background) were adoptively transferred into the mice. The presence of WT P14 T-cells only moderately affected tumor growth in this model. However maf-deficient P14 T-cells induced a strong regression of the tumor burden (Figure 5 a). One week post- transfer Applicants analyzed the endogenous CD45.1 CD8 T-cells and the transferred CD45.2 P14 T-cells from either P14 maT-Cre+ maf ^fi mice (maf-KO P14 CD8 T-cells) or from P14 maT-Cre- ma littermates (WT P14 CD8 T-cells). There was a slight increase of maf- deficient P14 T-cells among total CD8 T-cells compared to WT P14 T-cells in the tumor- draining LN. In TILs Applicants detected a much higher percentage of maf-deficient P14 T- cells, increasing the ratio of P14 CD8 T-cell/endogenous CD8 T-cells from 1 to 1 for WT P14 to 4 to 1 for maf-deficient P14 T-cells (Figure 5b). When tested for their capacity to produce cytokines upon gp33 peptide restimulation, maf-KO P14 T-cells from the tumor-draining LN showed a higher capacity to produce IFNy, IL-2 or TNFa compared to WT P14 T-cells (Figure 5b). In P14 T-cells from TILs, Applicants detected similar levels of Granzyme B, IL-2 or TNFa but higher capacity to produce IFNy in maf-deficient cells (Figure 5b). At the cell surface from TILs, similar levels of CD44 but lower expression of the inhibitory receptors PD-1 and LAG-3 were detected for maf-deficient compared to WT P14 T-cells.

In summary the higher capacity of maf-deficient tumor specific CD8 T-cells to accumulate inside the tumor and their higher potential for IFNy production with lower surface expression of PD-1 correlate with increased capacity to eliminate tumor burden in vivo.

Example 9:

ShRNA targeting maf efficiently decreases maf expression

Maf inactivation in mouse anti-tumor CD8 T cells led to an increased tumor control by tumor specific CD8 T cells. A translational application of those results is to alter maf expression in anti-tumor CD8 T cells from patients to increase the efficiency of adoptive anti-tumor T cell therapy. To achieve this goal several techniques can be used, including the use of shRNA or CRISPR/Cas9 specific for the maf gene/transcript, or the use of a dominant negative form of maf preventing its binding on DNA and so its effect on transcriptional targets.

As illustrated in Figure 7, P815 mastocytoma was stably transduced with a shRNA targeting maf or luciferase as control. Once established, the stable cell lines were assessed for their expression of maf by quantitative RT-PCR.

Namely, to test whether maf expression can be efficiently dampened, applicant tested a shRNA construct targeting maf. The shRNA was inserted in a retroviral vector encoding for the green fluorescent protein (pSIREN-ZsGreen). Retroviral particles were produced and used to transduce the p815 mastocytoma cell line with the shRNA targeting maf or a control shRNA targeting the firefly luciferase gene. After 48 hours, GFP expressing p815 cells were sorted by flow cytometry. GFP expressing p815 cells were cultured and after expansion applicant assessed the expression of maf in cells transduced with either maf targeting shRNA or control shRNA. There was a threefold decrease in maf level between the cells transduced with the maf targeting shRNA compared to the control transduced cells, reaching the background level detected in the no RT sample. So it is possible to efficiently decrease maf expression by using shRNA targeting maf. Additional methods can successfully lead to the inactivation of maf, either by inhibiting its functionlike the transduction of cells with a dominant negative form of maf ( Hurt et a I 2004) or inactivation of the gene using genome editing technology (Labott et al 2016).

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