The present invention concerns C1 q for use for treating allergy and/or asthma. The invention also relates to a pharmaceutical composition comprising C1 q and at least one allergen and to products comprising C1 q and at least one allergen as a combined preparation for use for treating allergy and/or asthma.

The human complement component C1 q ("C1 q") is the recognition component of the classical pathway of complement activation. The best-known ligands for C1 q are the Fc regions of aggregated immunoglobulin (lg)G and IgM molecules in immune complexes. Such binding triggers activation of the classical pathway, one of the three mechanisms for the activation of complement system. The result of activation of the complement system is the generation of C3 and C5 convertases that generate pro-inflammatory C3a and C5a anaphylatoxins and catalyse formation of pore-like membrane attack complex that inserts into cells membranes and cause damages by lytic or sublytic mechanisms.

Besides its well-known role in complement activation, C1 q is implicated in the biology of antigen presenting cells such as monocytes, macrophages and dendritic cells (DCs) which express or secrete this molecule (Lu et al. Cell Mol Immunol 5, 9-21 , 2008). In vitro treatment of monocytes by C1 q regulates cell differentiation and confers a tolerogenic phenotype to monocyte-derived DCs (Castellano et al. Eur. J. Immunol. 37, 2803-281 1 , 2007; Fraser et al. J. Immunol. 183, 6175-6185 2009). In contrast, C1 q deficiency impairs the recognition and clearance of apoptotic cells which leads to the development of autoimmunity (e.g. Systemic lupus erythematosus (SLE), glomerulonephritis) (Botto et al. Nat. Genet. 19, 56-59, 1998; Nauta et al. Eur. Immunol. 32, 1726-1736, 2002).

Dendritic cells are specialized antigen presenting cells that integrate a variety of incoming signals to orchestrate adaptive immune responses.

These cells have peculiar and opposite abilities, and therefore can be distinguished in two major and differently specialized subpopulations: on the one hand the effector DCs (also called pro-inflammatory DCs) and on the other hand the tolerogenic DCs (also called regulatory or DCreg).

The effector DCs, when activated, are crucial for the presentation of peptides and proteins to T and B lymphocytes and are widely recognized as professional antigen- presenting cells (APC), thanks to their ability to prime na ^' ive T cells. This subpopulation is involved in responses against infectious pathogens and tumors. Depending on the type of pathogen or antigen encountered and the profile of co- stimulatory molecules engaged, effector DCs have the capacity to induce different polarizations of T helper lymphocytes, that is to drive the development of Th1 , Th2 or Th17 effector CD4+ T cells.

The effector DC subpopulation can be divided into at least three distinct cell subsets regarding the helper T cells they are able to prime: DC1 cell subset which drives the development of Th1 cells (cells producing type 1 cytokines IFN-γ and IL-2), DC2 cell subset which drives the development of Th2 cells (cells producing type 2 cytokines IL-4, IL-5 and IL-13), and DC17 cell subset which drives the development of Th17 cells (cells producing IL-17).

In contrast, tolerogenic DCs mediate the suppression of antigen (Ag)-specific immune responses via the induction of regulatory (also called suppressive) CD4+ T cells, T-cell anergy and clonal deletion of T-cells. Tolerogenic DCs are thus critically involved in promoting and maintaining clinical and/or immunological tolerance, as well as regulating excessive and undesired immune responses. Regulatory/tolerogenic DCs have been shown to suppress inflammatory response to inhaled allergens (Swiecki and Colonna, Eur. J. Immunol., 40:2094-2098, 2010; Kuipers, Vaccine, 23(37) :4577-4588, 2005; Lambrecht, Allergy, 60(3): 271 -282, 2005).

Therefore, bidirectional interactions between DCs and T cells initiate either effector or tolerogenic responses, which are crucial to establish appropriate defence mechanisms, while precluding uncontrolled inflammation and immune response.

The Applicant recently showed in a pollen chamber study that induction of C1 q expression in DCs correlates with clinical efficacy induced by allergenic immunotherapy (Zimmer et al. J. Allergy Clin. Immunol. 129, 1020-1030, 2012; international patent application WO 2013/034569).

Selective targeting of pro-allergic complement pathways (in particular C3a and/or C5a) has been suggested as an attractive therapeutic option in allergic asthma (Kohl et al. Curr Opin Pharmacol. 2007;7(3):283-9).

The Applicant has now demonstrated that C1 q promotes tolerance induction in vivo in a murine Th2-driven asthma model. Particularly, in ovalbumin (OVA) sensitized mice, the effect of C1 q was studied with a dose range experiment (i.e. 10 μg, 50 μg and 100 μg) by assessing airway hyper-responsiveness (AHR), inflammatory cell infiltration (i.e. eosinophils and type 2 innate lymphoid cells (ILC2)) in broncho-alveolar fluids, Th2 cytokine production by OVA-specific lung T cells and seric OVA-specific IgE production. Except for OVA-specific IgE levels, all the parameters tested were significantly decreased in a dose dependent manner following C1 q therapy.

The optimal (i.e. 50 μg) dose of C1 q, in its native and heat-denatured forms, was further compared with an effective regimen (i.e. 60 μg) of dexamethasone (DEX), the gold standard for treating various acute and chronic inflammatory diseases. Thereby, the applicant demonstrated that native C1 q, but not heat-denatured C1 q, was as efficient as DEX to treat allergic asthma using readouts as described above.

Taken together the results identify C1 q as a molecule for treating allergy and/or asthma.

These results were further confirmed by the applicant in a birch extract sensitised mice model. As expected, both C1 q (50μg) and DEX treatment, when compared to the PBS group, reduced airway hyper-responsiveness (AHR), inflammatory cell infiltration (eosinophils) in broncho-alveolar fluids and Th2 cytokine production by birch extract- specific lung T cells.

Definitions

"C1 q" denotes the first subcomponent of the C1 complex of the classical pathway of complement activation. Throughout the specification, the terms "C1 q" and "C1 Q" are used indistinctively.

In human, C1 q is composed of 18 polypeptide chains: six C1 qA chains

(UniProt/Swiss-Prot accession number C1 QA HUMAN, SEQ ID NO:1 or any polymorphic variant thereof; mature form of 223 amino acids spanning positions 23-245 of SEQ ID NO:1 ), six C1 qB chains (UniProt/Swiss-Prot accession number C1 QB HUMAN, SEQ ID NO:2 or any polymorphic variant thereof; mature form of 226 amino acids spanning positions 28-253 of SEQ ID NO:2), and six C1 qC chains (UniProt/Swiss-Prot accession number C1 QC_HUMAN, SEQ ID NO:3 or any polymorphic variant thereof, mature form of 217 amino acids spanning positions 29-245 of SEQ ID NO:3). The A, B and C chains associate as six hetero-trimers to form the mature functional C1 q complex. Each C1 q chain contains an N-terminal collagen-like domain and a C-terminal globular domain (gC1 q). The majority of C1 complex ligands bind to the globular "recognition" domains of C1 q. In particular, the globular domains of C1 q form the recognition binding sites that interact with the exposed CH2 domains in the Fc regions of aggregated IgG and IgM in immune complexes. However, C1 q does not bind to IgA, IgE or IgD immune complexes (Sontheimer et al., J. Invest. Dermatol. 125:14-23, 2005).

C1 qA, C1 qB and/or C1 qC chains may comprise post-translational modifications, as compared with the sequences shown in SEQ ID NO:1 -3, respectively. For instance, C1 qA (as shown in SEQ ID NO:1 ) may comprise one or more of the following amino acid modifications: 5-hydroxylysine at position(s) 33, 48, 67, 100 and/or 103, and/or 4-hydroxyproline at position(s) 39, 45, 54, 57, 73, 85, and/or 97, and/or O- linked (Gal) at position(s) 33, 38, 67, 100, and/or 103, and/or N-linked (GlcNAc) at position 146 of the pre-protein.

For instance, C1 qB (as shown in SEQ ID NO:2) may comprise the following amino acid modification: Pyrrolidone carboxylic acid at position 28 of the pre-protein.

For instance, C1 qC (as shown in SEQ ID NO:3) may comprise one or more of the following amino acid modifications: 4-hydroxyproline at position(s) 36, 39, 42, 45, 54, 63, 81 , 93, 96, 99, and/or 105, and/or 5-hydroxylysine at position(s) 57 and/or 75, and/or O- linked (Gal) at position 75 of the pre-protein.

C1 q may denote human or non-human mammalian C1 q, in particular rat, mouse, cat, dog or monkey C1 q.

As used in the instant application, the term "C1 q" denotes the soluble C1 q complex (i.e. C1 q complex in free form) as well as polymerised C1 q complex, or biologically active fragments thereof.

As used herein, "polymerised C1 q complex" denotes covalently or non-covalently bound C1 q complexes, C1 q complexes bound onto solid surfaces or C1 q multimers.

In the context of the invention, "biologically active" denotes the capacity to display, induce or stimulate one or more of (i) anti-inflammatory and/or immunosuppressant activity, (ii) reduction of inflammatory cell recruitment, in particular eosinophils and/or type 2 innate lymphoid cells, or (iii) decreased Th2 cytokine expression by T cells.

A "Th2 cytokine" denotes IL-4, IL-5 and/or IL-13. Other cytokines are usually designated as "Th1 cytokines" (e.g. IFN-γ and IL-2) or "Th17 cytokines" (e.g. IL17 and IL23).

"Type 2 innate lymphoid cells" or "ILC2s" denote side scatter (SSC) low, lineage negative cells expressing ICOS as well as the IL-33 receptor T1 /ST2, i.e. SSC ^|0W Lin ICOS ⁺ T1/ST2 ⁺ cells.

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

A "subject" denotes a human or non-human mammal, in particular a rodent, a feline, a canine or a primate. Preferably, a subject denotes a human, in particular a child, a woman, a man.

As used herein, the word "comprising" is to be interpreted as encompassing all the specifically mentioned features of the claim, as well optional, additional, unspecified ones; The word "comprising" also discloses the embodiment in which only those features as specified in the claim are present (i.e. "consisting of").

C1 q therapeutic indication

The Applicant showed in vivo, in an OVA-sensitized murine model of asthma, that

C1 q:

- decreased airway hyper-responsiveness upon aerosol challenge to OVA,

- decreased inflammatory cell infiltration in the broncho-alveolar fluids, in particular eosinophils and ILC2 infiltration,

- decreased pro-allergenic Th2 cytokine production by OVA-specific lung T cells and

- was as efficient as DEX to treat allergic asthma using the readouts as described above.

The observed effects of C1 q on the inflammatory response in this model of asthma, together with the fact that 01 q mimicked the activity of dexamethasone, one of the most potent anti-inflammatory and immunosuppressive molecules, identify 01 q as an antiinflammatory and/or immunosuppressant agent for the treatment of allergy and/or asthma.

At last, the Applicant also demonstrated the regulatory effect of 01 q in an in vitro model of human pDCs. In particular, human pDCs stimulated with CpGA, a known activator of inflammatory response, resulted in an increase in pDCs pro-inflammatory cytokines, whereas pDCs stimulated with CpGA in presence of 01 q showed a limited increase in pro-inflammatory cytokines. The reduction of the inflammatory response of immune cells was also demonstrated when incubating CpGA stimulated pDCs with naive T cells. There also, the incubation of CpGA stimulated pDCs with naive T cells resulted in an increase of pro-inflammatory cytokines specific of T cells. By contrast, naive T cells incubated with pDCs stimulated with CpGA and treated with C1 q resulted in a limited increase of these pro-inflammatory cytokines.

The role of pDCs in the therapeutic effect of C1 q was further evidenced by the Applicant in a pDCs depleted OVA sensitised mice model. It was demonstrated that treatment with 01 q followed by challenge with OVA had no effect, on airway hyper- responsiveness and inflammatory cell infiltration (eosinophils) in broncho-alveolar fluids, in OVA sensitised mice depleted in pDCs when compared with OVA sensitised mice that were not depleted in pDCs and similarly treated with C1 q.

The invention thus relates to 01 q for use for treating allergy and/or asthma. An "allergen" is a substance, usually a protein, which elicits the production of IgE antibodies in predisposed individuals. Allergens may include pollen allergens (such as tree, herb, weed and grass pollen allergens), insect allergens (such as inhalant, saliva and venom allergens, e.g. cockroach, midge and house dust mite allergens and hymenoptera venom allergens), animal hair and dander allergens (from e.g. dog, cat, horse, rat, mouse, rabbit) and food allergens.

For instance, a protein allergen may be selected from the group consisting of a protein allergen of the genus Dermatophagoides; a protein allergen of the genus Felis; a protein allergen of the genus Ambrosia; a protein allergen of the genus Lolium; a protein allergen of the genus Cryptomeria; a protein allergen of the genus Alternaria; a protein allergen of the genus Alder, a protein allergen of the genus Betula; a protein allergen of the genus of Blomia; a protein allergen of the genus Quercus; a protein allergen of the genus Olea; a protein allergen of the genus Artemisia; a protein allergen of the genus Plantago; a protein allergen of the genus Parietaria; a protein allergen of the genus Canine; a protein allergen of the genus Blattella; a protein allergen of the genus Apis; a protein allergen of the genus Cupressus; a protein allergen of the genus Thuya; a protein allergen of the genus Chamaecyparis; a protein allergen of the genus Periplaneta; a protein allergen of the genus Agropyron; a protein allergen of the genus Secale; a protein allergen of the genus Triticum; a protein allergen of the genus Cynorhodon ; a protein allergen of the genus Juniperus ; a protein allergen of the genus Dactylis; a protein allergen of the genus Festuca; a protein allergen of the genus Poa; a protein allergen of the genus Lolium; a protein allergen of the genus Avena; a protein allergen of the genus Holcus; a protein allergen of the genus Anthoxanthum; a protein allergen of the genus Arrhenatherum; a protein allergen of the genus Agrostis; a protein allergen of the genus Phleum; a protein allergen of the genus Phalaris; a protein allergen of the genus Paspalum; and a protein allergen of the genus Sorghum.

Examples of various known protein allergens derived from some of the above- identified genus include : Betula (verrucosa) Bet v I ; Bet v II ; Blomia Bio 1 1 ; Bio t III; Bio t V; Bio t XII; Cynorhodon Cyn d I; Dermatophagoides (pteronyssinus or farinae) Der p I; Der p II; Der p III; Der p VII; Der f I; Der f II; Der f III; Der f VII; Felis (domesticus) Fel d I; Ambrosia (artemiisfolia) Amb a 1 .1 ; Amb a 1 .2; Amb a 1 .3; Amb a 1.4; Amb a II; Lollium (perenne) Lol p I; Lot p II; Lol p III; Lot p IV; Lol p IX (Lol p V or Lol p lb); Cryptomeria (japonica) Cry j I; Cry j II; Canis (familiaris) Can f I; Can f II; Juniperus (sabinoides or virginiana) Jun s I; Jun v I; Juniperus (ashei) Jun a I; Jun a II; Dactylis (glomerata) Dae g I; Dae g V; Poa (pratensis) Poa p I; Phi p I; Phi p V; Phi p VI and Sorghum (halepensis) Sor h I. "Allergy" is a condition characterized by production of allergen-specific IgE in response to a specific allergen, usually a protein. Allergy denotes in particular "immediate allergy" also called "type I hypersensitivity". In type 1 hypersensitivity, an allergen is presented to CD4+ Th2 cells specific to the allergen that stimulate B-cell production of IgE antibodies also specific to the allergen.

Clinical manifestations and symptoms of allergy may include nasal congestion, nasal pruritis, ocular pruritis, tearing, rhinorrhoea, sinusitis, rhinitis, sneezing, wheezing, asthma, conjunctivitis, systemic anaphylaxis, localized anaphylaxis (atopy), atopic dermatitis, eczema, and mastocytosis induced anaphylactic shock.

"Asthma" is a common chronic inflammatory disease of the airways characterized by variable and recurring symptoms, reversible airflow obstruction, and bronchospasm. Common symptoms include wheezing, coughing, chest tightness, and shortness of breath. In particular, in the method or use according to the invention, C1 q has antiinflammatory and/or immunosuppressant activity.

According to an embodiment, C1 q reduces inflammatory cell recruitment, in particular recruitment of eosinophils and/or type 2 innate lymphoid cells (ILC2s).

Type 2 innate lymphoid cells play a key role in type 2 immune responses by prompt production of type 2 cytokines (especially IL-5 and IL-13) in response to antigen-induced IL-25/33. Accumulating evidences tend to indicate that ILC2s are mediators of type 2 pathologies such as allergy and asthma.

Furthermore, C1 q decreases Th2 cytokine expression by allergen-specific T cells, in particular IL-5 and IL-13 expression.

Accordingly, C1 q preferably decreases Th2 cytokine expression by T cells specific for said allergen and/or reduces recruitment of type 2 innate lymphoid cells.

According to an embodiment, C1 q reduces airway hyper-responsiveness and/or bronchospasm when the disease is asthma. C1 q may be advantageously administered in combination (simultaneously, separately, or sequentially) with the allergen associated with the allergen-induced inflammatory response which is the hallmark of allergy and asthma. Without wishing to be bound by this theory, it is thought that C1 q, when administered in combination with the allergen, could act as an adjuvant and stimulate induction of tolerance to the allergen. Pharmaceutical compositions

C1 q is advantageously formulated in a pharmaceutical composition in order to be used in the medical indication or method of therapeutic treatment defined above.

The invention thus relates to a pharmaceutical composition comprising C1 q for use for treating allergy and/or asthma.

The invention further relates to a pharmaceutical composition comprising C1 q and at least one allergen.

The invention also relates to products comprising C1 q and at least one allergen as a combined preparation for simultaneous, separate or sequential use for treating allergy and/or asthma induced by said at least one allergen. Formulation of C1 q and said at least one allergen in separate products may indeed be appropriate in particular if a same route of administration in not adapted to administrate both C1 q and said at least one allergen.

Said pharmaceutical composition or products comprising C1 q and at least one allergen is(are) particularly intended for use for treating allergy and/or asthma induced by said at least one allergen, or to be administered to a subject suffering from allergy and/or asthma induced by said at least one allergen.

In an embodiment, C1 q and said at least one allergen are the sole active principles of the composition or products according to the invention.

According to an embodiment said pharmaceutical composition or products has(have) anti-inflammatory and/or immunosuppressant activity.

More specifically, said pharmaceutical composition or products:

- reduce(s) inflammatory cell recruitment, in particular recruitment of eosinophils and/or type 2 innate lymphoid cells (ILC2s), and/or

- decrease(s) Th2 cytokine expression by allergen-specific T cells, in particular IL- 5 and IL-13 expression, and/or

- reduce(s) airway hyper-responsiveness and/or bronchospasm when the disease is asthma.

Accordingly, the pharmaceutical composition or products preferably decrease(s) Th2 cytokine expression by T cells specific for said allergen and/or reduce(s) recruitment of type 2 innate lymphoid cells.

The pharmaceutical composition or products also reduce(s) airway hyper- responsiveness and/or bronchospasm when the disease is asthma.

The pharmaceutical composition or products comprise(s) with a pharmaceutically acceptable excipient, in addition to C1 q and said at least one allergen. "Pharmaceutically acceptable" means it is, within the scope of sound medical judgment, suitable for use in contact with the cells of humans and lower animals without undue toxicity, irritation, allergic response and the like, and are commensurate with a reasonable benefit/risk ratio.

As used herein, the term "pharmaceutically acceptable excipient" includes solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents, mucoadhesive excipients, and the like, that do not produce an adverse or other untoward reaction when administered to an animal, or a human, as appropriate. Excipients may further include, but are not limited to disintegrants, binders, lubricants, flavoring, colorants, or preservatives.

Preferably, C1 q is intended for administration by parenteral route, i.e. C1 q is formulated in a composition suitable for parenteral administration.

Preferably, said at least one allergen is intended for administration by oromucosal route, still preferably by sublingual administration.

Where mucosal administration is contemplated, the pharmaceutically acceptable excipient may advantageously be a "mucoadhesive carrier". As intended herein, a "mucoadhesive carrier" enables close and prolonged contact with a mucosa, in particular a mucosa of the oral cavity, and more particularly the sublingual mucosa, thereby enhancing-antigen (allergen) specific tolerance induction. Preferred mucoadhesive carriers as defined herein notably comprise chitosan, polymers of maltodextrin or carboxymethylcellulose.

For parenteral administration in an aqueous solution, for example, the solution should be suitably buffered if necessary and the liquid diluent first rendered isotonic with sufficient saline or glucose. These particular aqueous solutions are especially suitable for intramuscular and subcutaneous administration. In this connection, sterile aqueous media which can be employed will be known to those of skill in the art in light of the present disclosure.

The pharmaceutical compositions or the products according to the invention can include any conventional adjuvant. For oromucosal administration, the adjuvants may preferably be a Bifidobacterium, a lactic acid bacterium (either in the form of a cell suspension, freeze-dried cells, a lysate, purified sub-components, or purified molecules), or a combination of a corticosteroid with vitamin D3 or any metabolite or analog of the latter. Preferably, the pharmaceutical composition, or the products is(are) to be administered by the mucosal route, more preferably by the oromucosal route, and most preferably by the sublingual route. The medicaments according to the invention can be administered in various forms, such as dispersed forms, e.g. in suspensions or gels, or as dry forms, e.g. in powders, tablets, capsules, delayed release capsules, lyoc, or forms suitable to be administered in a metered-dosing device. The use of liposomes and/or microparticles and/or nanoparticles is also possible. The use and formation of liposomes and/or microparticles and/or nanoparticles are known to those skilled in the art.

In the frame of methods for treating allergy or asthma with the pharmaceutical composition or the products according to the invention, the administration regimen may be maintained for instance for a period of less than 6 weeks to more than 3 years.

In particular, C1 q is present in a therapeutically effective amount in said pharmaceutical compositions or product of the combined preparation.

Mammalian C1 q, and in particular human C1 q, can be readily purified from plasma, for instance by a method as described in the international patent application WO 2010/094901 , to prepare such pharmaceutical compositions and products.

Some variation in dosage will necessarily occur depending on the condition of the subject being treated. Dosages to be administered depend on individual needs, on the desired effect and the chosen route of administration. It is understood that the dosage administered will be dependent upon the age, sex, health, and weight of the recipient, concurrent treatment, if any, frequency of treatment, and the nature of the effect desired. The total dose required for each treatment may be administered by multiple doses or in a single dose. The person responsible for administration will, in any event, determine the appropriate dose for the individual subject.

The invention will be further illustrated by the following figures and examples.

FIGURES

Figure 1 : A: 1 D-gel electrophoresis of human C1 q, under reduced, denaturing conditions. B: Representative mass spectrometry spectra of human C1 q.

Figure 2: Experimental design. BALB/c mice were sensitized by intra-peritoneal (i.p.) injections with OVA/Alum (days 0 and 14) followed by aerosol challenges (days 21 -24) with OVA. BALB/c mice were intraperitoneal^ treated one hour before each aerosol challenge with either PBS, C1 q (10-100 μg/dose), heat-denatured C1 q (50 μg/dose) or DEX (60 μg/dose). AHR measurements and immunomonitoring were performed at days 25 and 26, respectively.

Figures 3-4: C1 q therapy significantly decreased airway hyperresponsiveness in a dose dependent manner. Airway responsiveness was determined by measuring the Penh value in response to metacholine. Horizontal bars represent the mean response +/- SEM within each group with each dot representing the Penh value obtained in an invididual animal, n = 6 mice for PBS, C1 q (10-100 μg/dose), heat-denatured C1 q (50 μg/dose) or DEX (60 μg/dose) treated mice, n = 7 for healthy mice in figure 3 and n = 6 for healthy mice in figure 4. ns = non-significant, ^* p < 0.05 and ^** p < 0.01 compared with mice treated with PBS. Data were compared using the nonparametric Kruskal-wallis test.

Figure 5: C1 q treatment significantly reduced airway resistance. Bronchial resistance was measured using a FinePointe RC system 24 hrs after the last aerosol. Results are expressed as mean values ± SEM, within each group, n = 6 mice for PBS, C1 q (50 μg/dose), heat-denatured C1 q (50 μg/dose) or DEX (60 μg/dose) treated mice, ns = nonsignificant, ^* p < 0.05 and ^** p < 0.01 compared with mice treated with PBS. Data were compared using the nonparametric Kruskal-Wallis test.

Figures 6-7: C1 q therapy significantly inhibited the OVA-induced eosinophil infiltration in broncho-alveolar lavages (BAL) fluid. Eosinophils were counted in BALs from mice receiving the various treatments. Results are shown as (mean +/- SEM). n = 5-6 mice for PBS, C1 q (10-100 μg/dose), heat-denatured C1 q (50 μg/dose) or DEX (60 μg/dose) treated mice, ns = non-significant, ^* p < 0.05 and ^** p < 0.01 compared with mice treated with PBS. Data were compared using the nonparametric Kruskal-Wallis test.

Figure 8: C1 q therapy significantly decreased the OVA-induced ILC2s infiltrates in BALs. The percentage of ILC2 (SSC ^low Lin lCOS ⁺ T1/ST2 ⁺ ) was analyzed in BAL fluid from mice receiving the various treatments. Results are shown as (mean +/- SEM). n = 5-6 mice for PBS, C1 q (50 μg/dose), heat-denatured C1 q (50 μg/dose) or DEX (60 μg/dose) treated mice, ns = non-significant and ^* p < 0.05 compared with mice treated with PBS. Data were compared using the nonparametric Kruskal-Wallis test.

Figures 9-12: C1 q treatment significantly reduced Th2 responses in the lungs.

Levels of IL5 and IL13 were assessed in culture supernatants of OVA-stimulated lung T cells using a Mouse Cytokine Bead kit. Results are shown as (mean +/- SEM). n = 6 mice for PBS, C1 q (10-100 μg/dose), heat-denatured C1 q (50 μg/dose) or DEX (60 μg/dose) treated mice, ns = non-significant, ^* p < 0.05 and ^** p < 0.01 compared with mice treated with PBS. Data were compared using the nonparametric Kruskal-Wallis test.

Figure 13: Therapeutic administration of C1 q did not decrease OVA-specific IgE production. Mice were treated as described in methods. Levels of seric OVA -specific IgE were measured by ELISA as described in methods. Ns = non-significant compared with mice treated with PBS. Data were compared using the nonparametric Kruskal-Wallis test.

Figure 14: C1 q therapy reduced airway hyper-responsiveness, eosinophils in BALs as well as Th2 responses in the lungs, in birch allergic mice._a) Airway responsiveness was determined by measuring the Penh value in response to metacholine. Horizontal bars represent the mean response +/- SEM within each group, n = 6 mice, b) Eosinophils were counted in BALs from mice receiving the various treatments. Results are shown as (mean +/- SEM). n = 6 mice, c) Levels of IL5 and d) IL13 were assessed in culture supernatants of birch pollen-stimulated lung T cells using a Mouse Cytokine Bead kit. Results are shown as (mean +/- SEM). n = 6 mice, ns = non-significant, ^* p < 0.05 and ^** p < 0.01 compared with mice treated with PBS. Data were compared using the nonparametric Mann Whitney test.

Figure 15: C1 q impedes human pDCs activation and reduces Th cytokine produced by CD4 ⁺ T cell. Supernatants were tested for the presence of a) IL-6, b) IL-8 and c) TNF-a by Human Cytokine Bead kit. Results are expressed as the mean variation ± SEM. ns = non-significant, ^* p < 0.05 and ^** p < 0.01 compared with treatment with CpGA. Data were compared using the nonparametric Mann Whitney test.

Figure 16: C1 q impedes human pDCs activation and reduces Th cytokine produced by CD4 ⁺ T cell. Supernatants were expressed for the presence of a) IFN-γ, b) IL-4 and c) IL-13 by Human Cytokine Bead kit. Data were obtained from 4 healthy distinct donors.

Figure 17: Depletion of pDCs in OVA-sentitized mice impede the therapeutic effect of C1 q. a) Airway responsiveness was determined by measuring the Penh value in response to metacholine. Horizontal bars represent the mean response +/- SEM within each group, n = 6 mice, b) Eosinophils were counted in BALs from mice receiving the various treatments. Results are shown as (mean +/- SEM). n = 6 mice, ns = nonsignificant, ^* p < 0.05 and ^** p < 0.01 compared with mice depleted in pDC and treated with C1 q. Data were compared using the nonparametric Mann Whitney test. EXAMPLES

EXAMPLE 1 : Characterization of Cl q

Human C1 q, purified from serum, was obtained from Calbiochem (#204876). 1D-gel electrophoresis

Protein sample was fractionated by 1 D-gel electrophoresis (#204876 Complement

C1 q, Human, Calbiochem, 1 .1 μς/μΙ). NuPAGE® LDS sample buffer and NuPAGE® reducing agent were used to prepare protein samples for denaturing gel electrophoresis with the NuPAGE® gels (Life Technologies). Proteins were separated by NuPAGE® Bis- Tris gel 4-12% with MES running buffer (1 and 5 μg/lane) and stained with Sypro Ruby and Coomassie® G-250 StainSimplyBlue (Life Technologies), respectively. Novex® sharp unstained protein standard was used to estimate molecular masses over a large range. Representative gel images are shown in Figure 1 A. Protein bands were then excised from gels (automated Bio-Rad spot picker), processed by tryptic in-gel digestion and analyzed by nLC-MS/MS. nLC-MS/MS

Tryptic peptides samples (in gel or in solution digestions respectively) were separated by reverse-phase chromatography using an Ultimate 3000 RS nano LC system (Thermo scientific). The nanoHPLC was coupled to an ESI-Qq-TOF mass spectrometer (Maxis, Bruker Daltonics). Peptides were loaded for 10 min onto the Acclaim PepMap100 column (100 μι x 2 cm; C18, 5 μηι, 100 A, Thermo scientific) with a flow rate of 12 μΙ_Ληίη and buffer A (2% ACN, 0.15% FA). Separation was then performed using an Acclaim PepMap RSLC column (75 μηι x 15cm; C18, 2 μηι, 10θΑ, Thermo scientific) with a flow rate of 450 nL/min. For accurate mass measurements, the lock mass option was enabled in MS mode: m/z 299.2945 (methylstearate, Sigma and m/z 1221 .9906 (Chip cube high mass reference, Agilent) ions generated in the electrospray process from ambient air were used for internal recalibration. Internal recalibration was performed using Data Analysis software. NanoLC-MS/MS data were analyzed using an in-house Mascot server (Matrix Science, version 2.3) to search Uniprot/Swiss-Prot databases, assuming tryptic digestion. Precursor mass and fragment mass were searched with initial mass tolerance of 8 ppm and 0.05 Da, respectively. The search included fixed modification of carbamidomethyl cysteine. Minimal peptide length was set to 6 amino acids and a maximum of one miscleavage was allowed. Peptide identifications were accepted if they could be established at a greater than 95% probability as specified by Mascot software. MALDI-MS

Protein sample (#204876 Complement C1 q, Human, Calbiochem,1 .1 μ9/μΙ) was reduced with TCEP 25 mM (5 min, RT) and then loaded onto a StageTips C8 and desalted with 0.1 % TFA. Proteins were directly eluted from the StageTips on the MALDI plate using 2 μΙ_ of Sinapinic acid matrix at 12 mg/mL in 50 % acetonitrile, 0.1 % TFA. Protein analyses were carried out on a MALDI TOF/TOF Autoflex Speed mass spectrometer (Bruker Daltonics) equipped with the smartbeamTM-ll laser technology. Spectra were obtained in linear mode by accumulating an average of ~ 2500 shots at a 1 KHz repetition rate. The calibration was performed externally in positive mode using the protein calibration standard II mixture (Bruker Daltonics). Data were processed with FlexAnalysis 3.3 software (Bruker Daltonics). Representative MS spectra are shown in Figure 1 B. Results

1 D-gel/nl_C-MS/MS analysis revealed two protein bands corresponding to C1 QA/C1 QB and C1 QC, respectively (Figure 1 A). Trace amounts of other proteins were slightly detected with SYPRO Ruby dye. The MALDI-MS analysis of the reduced C1 Q revealed the expected A, B and C chains (Figure 1 B, Tissot et ai, Biochemistry 2005, 44, 2602-2609). Finally, sample was also digested in solution with trypsin, and only C1 QA/B/C subunits were successfully identified by mass spectrometry, showing a high level of purity (data not shown).

EXAMPLE 2: The secondary structure of Cl q is irreversibly abolished after heat-incubation

In order to compare biologically active and inactive forms of C1 q in a murine asthma model, C1 q thermal stability was first evaluated by performing a CD temperature- dependent study that measures secondary structure unfolding while temperature is increased.

Circular dichroism (CD) spectroscopy

C1 q was obtained from Cabiochem® (#204876 Complement C1 q, Human, Calbiochem).

The CD spectra were recorded with a six-cell Peltier temperature-controlled Jasco- 815 spectropolarimeter. C1 q concentration was 1 .14 mg/mL, and 40 μΙ_ of sample (approximately 46 μg of protein) were loaded in 0.1 mm path length cells. The buffer consisted of 10 mM HEPES, 300 mM NaCI and 40% glycerol v/v (pH 7.2). A CD measurement control was performed at wavelength ranging from 190 to 260 nm. The temperature-dependent circular dichroism was monitored at temperatures ranging from 30°C to 90°C at a wavelength 200 nm (2.5 ^< C/min). CD Spectrum was smoothed using noise reduction. Results

The secondary structure of C1 q was stable until 54 °C and completely denatured at

84 °C. The native secondary structure of C1 q was not recovered following heat denaturation at 90 °C, then cooling down at 20 ^, demonstrating that C1 q secondary structure was irreversibly altered.

Thus, in the experiments described below, C1 q was incubated at 84 °C for 10 min. resulting in an irreversible denaturation of the protein. EXAMPLE 3: The human complement component Cl q promotes tolerance in asthma and airway diseases

3.1 MATERIALS AND METHODS

Mice, reagents and antibodies

Six- to eight-weeks-old BALB/c female mice were obtained from Charles River (L'Arbesle, France). Phosphate-buffer saline (PBS) was purchased from Invitrogen (Carlsbad, CA). OVA grade V with low endotoxin content was purchased from Sigma (St. Louis, MO) and was further purified on an endotoxin removing gel (Pierce, Rockford, IL). Residual endotoxin concentrations determined by Endochrome-K assay (R1708K, Charles River, Wilmington, MA) were always less than 0.1 EU/ μg protein. Human purified C1 q was obtained from Calbiochem (#204876) (distributed by Merck (Darmstadt, Germany) and DEX was purchased from Sigma. Therapy model and measurements of airway inflammation in BALB/c mice

For sensitization, mice were immunized intraperitoneal^ (i.p.) on days 0 and 14 with ^ 0μg OVA adsorbed on 2 mg AI(OH)3 (Pierce), administered in 100 μΙ PBS. From day 21 to 24, a daily 20 min aerosol challenge was performed with 1 % w/v OVA using an aerosol delivery system (Buxco Europe Ltd, Winchester, UK). To test its potential tolerogenic activity, C1 q (10-100 μg/dose) or heat-denatured C1 q (50 μg/dose) was administered intraperitoneal^ one hour before each aerosol challenge. PBS and DEX (60 μg/dose) were administered as negative and positive controls, respectively. Measurements of AHR were performed by whole body plethysmography (Buxco) and results were expressed as enhanced pause (Penh). The Penh index, expressed as an increase relative to the baseline airway resistance, was obtained by dividing the Penh value measured after exposure to increased inhaled metacholine (from 0 to 50 mg) with the one measured after inhalation of nebulised PBS, as previously described (Razafindratsita et al., J Allergy Clin. Immunol. 120, 278-285 (2007)). We complemented those Penh measurements with invasive determination of resistance that directly measures pulmonary function. Briefly, mice anesthetized with ketamine/xylazine by i.p (100 mg/kg and 10 mg/kg, respectively, Centravet, Maisons-Alfort, France) were carefully intubated orotracheally. Animals were then placed in a plethysmograph and connected via the endotracheal cannula to a FinePointe RC system (Buxco). Inhalation exposure in orotracheally intubated animals was focused to the lungs, with no nasal nor oral intake. Bronchial resistance was measured using the FinePointe RC system after exposure to increasing doses (i.e. 1 .875, 3.75, 7.5, 15 mg/ml) of methacholine using a protocol adapted from Swedin and al. (Int. Arch. Allergy Immunol. 153, 249-258 (2010)) .

For analysis of inflammatory cells in broncho-alveolar lavages (BAL), mice were anesthetized with pentobarbital/xylazine by i.p (50 mg/kg and 10mg/kg, respectively, Centravet, Maisons-Alfort, France), and BAL performed with 3 x 400 μΙ PBS. BAL fluid was centrifuged at 800 g for 10 min at 4 ^< C. Cell pellets were resuspended in PBS, spun onto glass slides by cytocentrifugation, fixed and stained with May-Grijnwald Giemsa (Reactifs RAL, Martillac, France). Eosinophils and macrophages were counted under light microscopy using a 200-fold magnification.

Flow cytometry analysis (FACS) of type 2 innate lymphoid cells (ILC2) in BALs To analyse the presence of inflammatory ILC2s in BAL fluids, cells were stained, at 4 ^< C for 15 min, with monoclonal antibodies (mAbs) against CD4 (GK1 .5), CD3 (clone 1452CM), CD8 (clone 53-6.7), CD1 1 b (clone M1 /70), CD19 (clone 1 D3), CD1 1 c (clone N418), FceR1 (clone MAR-1 ), all conjugated to phycoerythrin (PE), T1/ST2 (clone DJ8) conjugated to fluorescein (FITC), ICOS (clone C398.4A) conjugated to allophycoerythrin. Corresponding isotype-matched mAbs were used as controls. All antibodies were purchased from e-Bioscience (San Diego, CA) except for mAbs against T1/ST2 from MD bioscience (St Paul, MN). The samples were acquired by using a FACSVerse (Becton Dickinson, Le pont de Claix, France) and analyzed with FlowJo software.

Analysis of allergen-specific T cell responses in the lungs

To recover cells from lung tissues, one lobe was incubated for 1 h in RPMI supplemented with digest reagent (collagenase 75 U/mL; Roche, Basel, Switzerland). Isolated cells were filtered through a 70-μηι sieve and washed twice before resuspension in culture medium. Lung cells were plated at 10 ⁶ cells per well and stimulated with OVA (100 μο/ηιΙ) or medium alone. After 72 hours at 37°C in 5% C02 / 95% air, IL5 and IL13 were measured in culture supernatants using a Mouse Cytokine Bead kit (Merck Millipore, Darmstadt, Germany) and a Magpix system (Luminex, Austin, TX). Analyses were performed according to manufacturer's instruction.

Measurement of allergen-specific IgE antibody responses

Sera were obtained after centrifugation of blood samples at 10 000 rpm for 10 min. For detection of OVA-specific IgE antibodies, were assessed in sera (at a 1 /50 dilution) using the mouse ovalbumin specific IgE ELISA assay kit (AbD serotec, Dusseldorf, Germany) according to manufacturer's instructions. Optical densities were measured using an ELISA plate reader at 405 nm.

Statistical analysis

Statistical differences between groups were assessed using a nonparametric test

(Kruskal-Wallis). Results were considered statistically significant for a p-value below 0.05. Statistical and graphical analyses were performed using the Prism 5 software (GraphPad, La Jolla, OA). 3.2 RESULTS

Design of immunotherapy in an OVA asthma mouse model

As described elsewhere (Razafindratsita et al. J Allergy Clin. Immunol. 120, 278-285 (2007)), mice sensitized with OVA using the protocol summarized in figure 1 , develop AHR associated with elevated Penh values detectable by whole body plethysmography, as well as signs of lung inflammation with cellular infiltrates. The therapeutic effect of the human complement component C1 q was tested in this in vivo murine model of established asthma as described in figure 2.

C1q reduced airway hyperresponsiveness as well as lung inflammation in an OVA asthma mouse model

As expected, healthy (i.e. nonsensitized) mice exhibited low Penh values, whereas OVA-sensitized animals treated intraperitoneal^ with PBS displayed a high AHR (Figures 3 and 4). Intraperitoneal C1 q treatment induced a dose dependent significant (p < 0.01 ) reduction of AHR when compared to PBS treated mice (Figures 3). Interestingly, administration of heat-denatured C1 q had no impact on AHR (Figure 4). Also, OVA- sensitized mice intraperitoneal^ treated with DEX exhibited low Penh values (p < 0.01 ) as shown in figure 4.

Invasive monitoring of lung function in those animals confirmed as well a significant decrease in pulmonary resistance in groups receiving either C1 q or DEX when compared to the PBS group (Figure 5; p < 0.05 and p < 0.01 , respectively). Administration of heat- denatured C1 q had no impact on pulmonary resistance when compared to PBS treated mice (Figure 5).

The decrease of AHR observed in C1 q treated mice was associated with a significant dose dependent decrease (p < 0.01 ) in eosinophil counts in BALs when compared to the PBS group (Figure 6). A similar decrease was showed after DEX treatment (Figure 7; p < 0.01 ). As expected, administration of heat-denatured C1 q had no effect on eosinophily (Figure 7).

Inflammatory ILC2s are also a part of lung infiltrating cells and dramatically increase in BAL fluid from OVA-sensitized mice (Barlow et al. J. Allergy Clin. Immunol. 129, 191 - 198 (2012)). ILC2s from BAL fluid are defined in flow cytometry as side scatter (SSC) low lineage negative cells expressing ICOS as well as the IL-33 receptor T1/ST2 (SSC ^|0W Lin ICOS ⁺ T1/ST2 ⁺ ) (Barlow et al. J. Allergy Clin. Immunol. 129, 191 -198 (2012)). A significant (p < 0.05) decrease in ILC2s was observed in both DEX and C1 q treated mice when compared to PBS treated mice (Figure 8) whereas the percentage of ILC2s in BAL fluid from heat-denatured C1 q treated mice was comparable to the one observed in the PBS group (Figure 8).

C1q therapy significantly decreased Th2 responses in the lungs.

We further investigated whether administration of C1 q altered cytokines produced in lungs by OVA-specific T cells re-stimulated by OVA in vitro. A significant (p < 0.01 ) decrease in IL-5 and IL-13 secretion by lung T cells was observed in both DEX and C1 q treated mice when compared to PBS treated mice (Figures 9-12). Conversely, lung T cells from heat-denatured C1 q treated mice secreted similar levels of IL-5 and IL-13 when compared to the PBS group (Figures 10 and 12). Interestingly, similar results were obtained in the spleen (data not shown).

C1q therapy did not induce down-regulation of OVA-specific IgE antibodies

As expected, OVA-sensitized mice treated with PBS increased OVA-specific IgE antibodies. However, C1 q had no significant impact on OVA-specific seric IgE antibodies

(Figure 13).

CONCLUSION

Based on data obtained in 3 independent experiments, C1 q acted similarly to dexamethasone, the gold standard of glucocorticoids, in counteracting OVA-induced airway hyperresponsiveness and recruitment of pro-inflammatory cells (i.e. eosinophils and type 2 innate lymphoid cells) in the lung. In addition, both C1 q and DEX inhibited Th2 cytokine production in the lung. In conclusion, we clearly showed the anti-inflammatory effect of C1 q in a Th2-driven asthma model, suggesting a potential therapeutic benefit of this molecule in humans.

Example 3.3 - Complementary results in a Birch asthma mouse model Protocols:

The same protocol was reproduced in which OVA was replaced with a birch pollen extract. The birch pollen extract was produced by Stallergenes.

For sensitization on days 0 and 14, birch pollen extract containing a dose equivalent to 10 μg Bet v 1 adsorbed on 2 mg AI(OH) ₃ in 100 μΙ PBS was administered.

A daily 20 min aerosol challenge was also performed from day 21 to 24, a daily 20 min challenge with birch pollen extracts equivalent to 1 mg Bet v 1 using an aerosol delivery system (Buxco Europe Ltd, Winchester, UK)

For the analysis of allergen-specific T cell responses in the lungs, cells from lung tissue were isolated according to the protocol defined previously and then stimulated with birch pollen extract, equivalent to 10 μg Bet v 1 , or medium alone.

Results:

Similar to the OVA asthma mouse model, the effect of C1 q (50μg) and DEX in the birch pollen asthma mouse model reduced AHR (Figure 14(a)), eosinophils in BALs (Figure 14(b)) and Th2 cykokines (i.e. IL5 and IL13, Figures 14(c) and (d) respectively) in lungs when compared to the PBS group.

EXAMPLE 4: Cl q prevents human pDCs activation and decreases Th cytokine produced by CD4+ T cell

Protocols:

The effect of C1 q on human pDCs activation under serum free condition was assessed.

Plasmacytoid DCs (pDCs) were isolated from PBMCs by negative selection using the MACS Plasmacytoid Dendritic Cell Isolation Kit (Miltenyi Biotec), respectively, and an autoMACS Pro Separator, according to the manufacturer's instructions. Such DCs were confirmed to express CD123 and CD303 markers for pDCs, by using flow cytometry using a FACSVerse cytometer (BD Biosciences, Le Pont de Claix, France) and the FlowJo analysis software (Treestar).

In a first experiment, pDCs were obtained from PBMCs of healthy donors (n=6). pDCs were plated in a 96-well plate at 1 .10 ⁵ /well at 37 ^< C in humidified air containing 5% C0 ₂ , in CellGro ^® GMP Serum-free Dendritic Cell Medium (CellGenix, Freiburg, Germany) supplemented with 10 μg/ml Gentamicin and were stimulated with CpGA (2 μg/ml, Invivogen) in presence or absence of soluble or immobilized C1 Q (^g/ml or 50μg/ml, respectively) for 24 h at 37°C and 5% C02. Non-treated pDCs (NT) served as a negative control (Cells incubated with medium alone). Cytokine measurement was performed in supernatants collected 24 h after treatment of pDCs or in supernatants from pDCs/T-cells co-cultures using the multiplex cytokine quantification assays. Cytokines IL-6, IL-8 and TNF-a were measured using the Milliplex MAP human kit Cytokine/Chemokine Magnetic Bead Panel (Millipore, Le Pont de Claix, France) and analyzed using an MagPix Luminex xMAP technology (Millipore).

In a second experiment, the polarization of nal ^' ve allogeneic CD4 ⁺ T cells after co- culture with treated pDCs under serum free conditions was analyzed. Treated pDCs were washed once with PBS and once with serum free medium and cultured in a 48-well plate in serum-free medium with allogeneic CD4 ⁺ naive T cells at a 1 :10 pDCs/T cells ratio for 5 days. Naive CD4 ⁺ T cells were isolated from PBMCs by negative selection using the MACS naive CD4 isolation kit II (Miltenyi Biotec), according to the manufacturer's instructions. Such naive T cells were confirmed to have purity greater than 95% based on CD4 and CD45RA expression evaluated by flow cytometry. Supernatants were analyzed for cytokine release. To this aim, pDCs were either non treated (NT) or incubated in solution for 24 h with either C1 q, CpGA or CpGA + C1 q, then washed and co-cultured with purified allogeneic na ^' ive CD4 ⁺ T cells. T cell polarization was monitored after 5 days by measuring cytokines - IFN-γ, IL-4 and IL-13. Cytokine measurement was performed in supernatants from pDCs/T-cells co-cultures using the multiplex cytokine quantification assays. Cytokines IFN-γ, IL-4, and IL-13 were measured using the Milliplex MAP human kit Cytokine/Chemokine Magnetic Bead Panel (Millipore, Le Pont de Claix, France) and analyzed using an MagPix Luminex xMAP technology (Millipore)

Results:

As regards the first experiment and as illustrated in Figures 15(a), (b) and (c), non- treated or C1 q (in solution or immobilized) treated pDCs did not increase pro-inflamatory cytokines. In contrasts, CpGA activated pDCs increased both IL-6, IL-8 and TNF-a. Markedly, CpGA-C1 q treated pDCs secreted significantly less of these cytokines demonstrating that C1 q (in solution or immobilized) counteract pDCs activation.

Considering the second experiment and as illustrated in Figures 16(a), (b) and (c),

CpGA-pDCs induced IFN-γ, IL4 and IL-13 production by T cells, respectively. In contrast, C1 q or CpGA-C1 q pDCs markedly decreased the secretion of most cytokines tested, i.e. IFN- Y, IL4 and IL-13, when compared with non-treated pDCs. EXAMPLE 5: Depletion of pDCs in OVA-sentitized mice impede the therapeutic effect of C1 Q Protocols:

To assess C1 q ability to modulate immune responses through pDCs, pDC depleted mice were treated or not with C1 Q. pDC depleting 120G8 antibodies were injected in OVA sensitized mice 2 hours before OVA challenge (see 3.1 Materials and Methods under Example 3), thus inducing the loss of pDCs in those mice. As described in Razafindratsita A et al. ("Improvement of sublingual immunotherapy efficacy with a mucoadhesive allergen formulation", J Allergy Clin Immunol 120, 278-285, 2007), mice sensitized with OVA develop airway hyper-responsiveness (AHR) associated with elevated Penh values detectable by whole body plethysmography, as well as signs of lung inflammation with cellular infiltrates.

Results:

As expected and illustrated in Figure 17, healthy (i.e. non sensitized) mice exhibited low Penh values, whereas OVA-sensitized animals treated intraperitoneal^ with PBS displayed a high AHR and eosinophils in BALs. pDCs depleted mice sensitized to OVA also exhibited high AHR and eosinophils in BALs (Figure 17), suggesting that the loss of pDCs did not alter sensitization. As a positive control, OVA-sensitized mice intraperitoneal^ treated with DEX exhibited low Penh values (Figure 17(a)) as well as a decrease percentage of eosinophils in BALs (Figure 17(b)). Markedly, intraperitoneal C1 q treatment induced a significant (p < 0.01 ) reduction of AHR when compared to pDC depleted/C1 q treated mice (Figure 17(a)). This decrease of AHR observed in C1 q treated mice was also associated with a significant decrease (p<0.01 ) in eosinophil counts in BALs (Figure 17(b)). Strikingly, intraperitoneal C1 q treatment did not reduce AHR and eosinophils in BALs in pDC depleted OVA sensitized mice, suggesting that C1 q acts via pDCs to prevent asthma.