Towards an HIV Cure Pre-Conference Symposium 20 & 21 July 2012

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1 Towards an HIV Cure Pre-Conference Symposium 20 & 21 July 2012 Your logo Natural control of HIV infection is associated with an isotype switched IgG antibody response to HIV Gag antigens in patients with 'non-protective' HLA-B alleles Martyn A French 1, Rob J Center 2, Kim M Wilson 3, Ibrahim Fleyfel 1, Sonia Fernandez 1, Anna Schorcht 2, Ivan Stratov 2, Marit Kramski 2, Stephen J Kent 2, Anthony D Kelleher 4 1. University of Western Australia, Perth, Australia 2. University of Melbourne, Melbourne, Australia 3. NRL, Melbourne, Australia 4. University of New South Wales, Sydney, Australia

2 Immune control of HIV infection CD8 + T cells and protective HLA-B molecules (HLA-B*5701, -B2705, -B*14+Cw0802, -B*52) NK cells (KIR and HLA-Bw4 or HLA-C) Plasmacytoid dendritic cells Antibodies - Antibody-dependant cell-mediated cytotoxicity? - Antibodies to Gag proteins? - IgG2 antibodies?

3 Diversification of antibody responses through immunoglobulin isotype switching T FH IFN-γ IL-4 APRIL, BAFF, TGF-β, IL-10 IL-21 IgM IgG Subclasses IgE IgA IgG3 IgG1 IgG2 IgG4 Abbas et al. 2007

4 Functional characteristics of IgG2 antibodies Polysaccharide antigens induce a predominantly IgG2 antibody response Preferential binding to FcγRIIa Deglycosylation of Fc region does not decrease binding to FcγRIIa Covalent dimerisation Dominant IgG subclass in plasma immune complexes

5 Patients and Methods HIV Patients 32 HIV controllers, including 14 elite controllers 21 non-controllers with RNA >10,000 cps/ml and CD4 + T cell count <100/µL Methods IgG1 and IgG2 Abs to HIV proteins by WB assay IgG1 and IgG2 Abs to gp140 Env protein and rp55 by ELISA NK cell-mediated ADCC activity to gp140 Env protein and Env and Gag peptides Sequenced-based HLA typing on genomic DNA

6 IgG1 antibodies to all HIV proteins, except gp41, are higher in HIV controllers IgG 1 Response 5 4 P = P < P = P < P < P = P = Band Intensity Controllers gp120 Non-controllers gp120 Controllers gp41 Non-controllers gp41 Controllers p66 Non-controllers p66 Controllers p51 Non-controllers p51 Controllers p32 Non-controllers p32 Controllers p24 Non-controllers p24 Controllers p18 Non-controllers p18

7 Gag antigens dominate in the IgG2 antibody response against HIV IgG 2 Response 5 P = P = P = Band Intensity Controllers gp41 Non-controllers gp41 Controllers p24 Non-controllers p24 Controllers p18 Non-controllers p18

8 IgG2 antibodies to rp55 were only detected in HIV controllers IgG1 anti-rp55 IgG2 anti-rp OD IgG1 P=0.09 OD IgG2 P= controllers non neg controllers controllers non controllers neg

9 IgG1 and IgG2 antibodies to gp140 Env protein did not differentiate controllers and non-controllers IgG1 anti-gp140 Env protein IgG2 anti-gp140 Env protein P = 0.12 P = 0.34 Endpoint titer (log10) Endpoint titer (log10) non-controllers controllers non-controllers controllers non-controllers

10 HIV controllers exhibit higher ADCC activity to gp140 Env protein ADCC activity against gp140 Env protein was significantly higher in elite controllers than non-controllers (p=0.03)

11 Antibody responses to HIV proteins in controllers without or with protective HLA-B alleles Antibody response HIV Controllers without protective HLA-B alleles # (median, IQR) HIV Controllers with protective HLA-B # alleles (median, IQR) P value IgG1 anti-p18 4 (3-4) 3 (2-4) 0.11 IgG1 anti-p24 4(3-4) 4 (2-4) 0.65 IgG1 anti-p (2.25-4) 2 (2-3) 0.04 IgG1 anti-p51 4 (2.25-4) 4 (2.25-4) 0.65 IgG1 anti-p66 4 (4-4) 4 (3.25-4) 0.42 IgG1 anti-gp41 4 (4-4) 4 (4-4) 1.0 IgG1 anti-gp (2-4) 3 (2.25-4) 0.95 IgG2 anti-p (1-3) 1 (1-2) 0.10 IgG2 anti-p (0-3.75) 0 (0-2) 0.16 IgG2 anti-gp41 1 (1-2) 1 (1-2) 0.91 ADCC antibodies to gp140 Env protein ( ) ( ) 0.51 # = HLA-B*57, -B*27, -B*52, B*14+Cw0802

12 IgG2 antibodies to p24 are higher in HIV controllers who do not carry HLA-B*57 IgG1 anti-p18 IgG1 anti-p32 IgG2 anti-p18 IgG2 anti-p24

13 High-level IgG2 antibodies to one or more Gag protein (p18, p24, rp55) are most common in HIV controllers not carrying protective HLA-B alleles IgG2 anti-gag HLA-B*57 or B*52 HLA-B*27 or B*14 No protective HLA-B allele Yes No p=0.016 and for trend

14 Summary and Conclusions IgG2 antibodies to HIV Gag proteins may contribute to control of HIV infection Preferential binding to FcγRIIa (major FcγR on pdcs) Deglycosylation of Fc does not decrease binding to FcγRIIa Phagocytosis-enhancing antibodies (bacteria,?viruses) Such antibodies might enhance innate responses to HIV and/or adaptive immune responses to Gag Strategies for vaccination with HIV Gag proteins might include enhancement of IgG isotype switching

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16 Induction of innate responses to HIV and/or adaptive responses to Gag by pdc and isotypeswitched IgG antibodies: a hypothesis IFN-α and IFN-λ Interferon-stimulated genes IgG1 IgG2 Gag + RNA IgG3 FcγRIIa CD70 TLR7 MHC I X MHC II IRF-7 NFκB pdc-dependant NK cell activation Pro-inflammatory cytokines CD8 + T cell B cell CD4 + T cell = Endosomes

17 VIR 201 study: control of HIV replication was better in patients possessing high affinity FcγRIIa genotypes who produced IgG2 anti-p24 after vaccination with rfpv P=0.002 for FC recipients (o) P= for all patients French MA et al. AIDS 2010;24:

18 IgG1 and IgG2 antibodies to bacteria increase production of Th17 promoting cytokines from cultures of modc and CD4 + T cells den Dunnen J et al. Blood 2012;120:112-21

19 Human IgG subclasses: proportion of serum IgG and order of isotype switching Median proportion of serum IgG (%) Order of isotype switching

20 B cell immunoglobulin isotype switching increases functional diversity of IgG antibodies Complement activation Binding to FcγRI Binding to FcγRIIa Binding to FcγRIIIa Covalent dimerisation Deglycosylation of Fc does not decrease binding to FcγRIIa IgG3 IgG1 IgG2 IgG4

21 Deglycosylation of the Fc region of IgG2 by EndoS does not decrease binding to FcγRII Allhorn M et al. PLoS One. 2008;3:e1413