1. Professeur Patrice DEBRE Laboratoire d’Immunologie Cellulaire et Tissulaire INSERM U945 Hôpital Pitié-Salpêtrière; Paris "Vers un vaccin contre le SIDA : rôle des cellules NK"

2. Pathogen Pathogenicity Measles Hépatitis Polio Rabies Diphtéria Tétanos Cholera Vaccines

3. Vaccine INFECTION virus CD4 infected cells PATHOGENESIS CD4 non infected cells NK cells    PATHOGENESIS NK cells CD4 non infected cells

4. Kill NK CD4 + - NKp44 MHC-I NKp44L NKp44L expression by CD4 + T cells from HIV-infected patients % NKp44L 0 10 20 30 40 3-3- 3-3- 4+4+ 4+4+ 8+8+ 8+8+ Control PBMC HIV + PBMC CD4 / mm 3 0 250500 750 1000 0 1010 2020 3030 4040 p=0.002 % NKp44L E/T ratio 0 10 20 30 40 100/150/125/112.5/1 44L + 44L - % NK Lysis Vieillard et al Proc Natl Acad Sci USA (2005) 0.1 1 10100 1000 viral load(x 1000) 0 10 20 30 40 % NKp44L p=0.005

5. NKp44L expression is induced by a specific gp41 motif HR1HR2 NH 2 Fusion Peptide TM 517 532 558 595 643 678 3S motif HIV-1 gp41 Env 3S : very conserved motif & spécific to HIV-1 0 10 20 30 50/125/112/16/1 E/T ratio +3S 0 10 20 30 40 +3S 11020 anti-3S (  g/ml) % NK lysis Vieillard et al Proc Natl Acad Sci USA (2005) Vieillard et al AIDS (2006) NKp44L 2.7% 17.4% 3S UT CD4

6. Anti-3S Ab : a predictive value for the evolution of the disease ? Multivariate study between 40 patients (first quartile) with a slope CD4>2.7/month and 40 patients (last quartile) with slope CD4<-6.9/month Variable Odds-ratio IC 95 p Sexe 0.372 M 1 W 1.83 0.49-6.87 Age (x10y) 1.30 0.76-2.23 0.334 CD4 (x100) 0.58 0.42-0.81 0.001 Log VL 1.17 0.55-2.51 0.682 Anti-3S Ab 2.89 1.6-5.17 <0.001 (x100) Vieillard et al AIDS (2006) Unpublished data

7. 1.3: Anti-3S Ab : a predictive value for the evolution of the disease ?

8. Anti-3SHIV-1 NKp44L CD4 NKLysis Summary-1

9. Conclusion-1 - NKp44L is specifically expressed on CD4+ T cells from HIV-1 patients; - NKp44L is induced par a specific peptide from the gp41 HIV-1 protein; - Anti-3S antibodies are predictive of the evolution of the disease evolution.

10. No expression of NKp44L in CD4 + T cells infected by HIV-1 : A new escape mechanism mediated by Nef Fausther Bovendo et al (In press) NKp44L HIV-p24 HIV viruses Relative p24 + NKp44L + NKp44L expression 10 0 10 1 10 2 10 3 10 4 0 100 150 200 50 52.1% UI 10 0 10 1 10 2 10 3 10 4 WT 71.3% 10 0 10 1 10 2 10 3 10 4 GAG 68.1% 10 0 10 1 10 2 10 3 10 4 0 100 150 200 50 67.2% POL 10 0 10 1 10 2 10 3 10 4 73.6% gp120 10 0 10 1 10 2 10 3 10 4 gp41 90.4% 10 4 10 1 10 2 10 3 10 4 10 0 10 1 10 2 10 3 11.7% NEF 60.2% VIF 10 0 10 1 10 2 10 3 0 100 150 200 50 TAT 72.4% Recombinant vaccinia viruses 0 5 10 15 20 WT  nef *

11. p24 + NKp44L + (flod increased) WT  nef G2A P76/79A L168/169A HIV Nef variants 0 5 10 15 20 * * Effect of Nef mutants on NKp44L expression

12. 0 10 20 30 40 50 60 70 100/150/125/112.5/1 E/T ratio % NK lysis Effect of Nef mutants on NK cytotoxicity

13. Conclusion-2 - NKp44L is non-expressed on HIV-infected CD4+ T cells; - Retention of NKp44L by Nef HIV protein; However, - The mechanism of Nef inhibition remains unknown.

14. 3- Vaccine strategies : Macaque model « proof of concept » 3.1 : Macaque model of SHIV infection 3.2 : Preventive vaccination

15. SHIV 162P3 -infected macaques model : Relationship between CD4 cell decreases, NKp44L expression and anti-3S Ab. Days post-infection Vieillard et al AIDS (2008)

16. Proofs of concept : Immunization of macaques by the 3S peptide KLH KLH-3S CD4 / mm 3 Viral load Vieillard et al Proc Natl Acad Sci USA (2008) Days post-infection

17. Effect of 3S vaccination on CD4 apoptosis, NK activity et T cell-activation % CD4 + AnnexinV + Days post-infection 0 10 20 30 40 50 UI142142LN * ** * % NK lysis Days post-infection 0 25 50 75 100 0142142LN ** * Vieillard et al Proc Natl Acad Sci USA (2008)

18. Conclusions 1- Pathophysiology : role of NKp44L - Depletion of non-infected CD4 + cells - In infected cells: Escape mechanism by Nef 2- Immunotherapic interventions - Preventive vaccine : in macaque model, we have observed : - high production of anti-3S Ab; - low expression of NKp44L on CD4 cells. Stable level of the CD4 cells in absence of effect on the viral load !

19. Pitié-Salpêtrière Hospital, Paris France Laboratory of Cellular and Tissular Immunology Hugues Fausther Bovendo Vincent Vieilllard Patrice Debré Clinical Epidemiology Dominique Costagliola Department of virology Henry Agut Daniel Candotti Acknowlegments CEA, Fontenay-aux-roses, France Laboratory of Immuno-Virology Roger Le Grand Nathalie Bosquet Pasteur Institute, Paris, France Department of virology Nathalie Sole-Foulon Olivier Schwartz Harvard University, Cambridge, MA Jack Strominger