Outline

1. Contribution of the immune system to HIV persistenceSharon R LewinDirector, Infectious Disease Unit, Alfred HospitalProfessor, Department of Medicine, Monash UniversityCo-head, Centre for Virology, Burnet Institute, Melbourne, AustraliaTowards an HIV Cure, 5th IAS Conference, Rome, 2011

2. Outline • Establishing HIV latency • Where and how are resting T-cells infected? • Chemokines • Dendritic cells • Maintaining HIV latency • Homeostatic proliferation • Inflammation • Role of the adaptive immune response • Relevance to strategies for cure

3. establishing HIV latency

4. Latent infection can be established in many T cells Latent reservoir Bone marrow Thymus Peripheral circulation Ag M M M M Central memory Effector/ transitional Naive Multipotent progenitor cells Naïve T cells Transitional memory Central memory Chun et al., Nature 1997; 387:183; Finzi et al., Science 1997; 278:1295; Brooks et al., Nat Med 2001; 7:459 ; Chomont et al., Nat Med 2009; 15: 893; Dai et al., J Virol 2009: 83(9):4528-37; Carter et al., Nat Med 2010; 16: 446; Wightman et al., J Infect Dis 2010; 202(11):1738-48

5. 100 80 Contribution (%) to the HIV reservoir size 60 40 20 0 TN TCM TTM TEM TTD CD45RA CCR7 CD27 + + + - + + - - + - - - + - - The main reservoir is central and transitional memory T-cells Chomont et al., Nature Med 2009;15: 893

6. GI tract is enriched for latently infected cells HIV DNA Copies per million cells N=8, time on HAART with undetectable HIV RNA 2.8 – 12 years Chun et al., J Infect Dis 2008; 197:714; Yukl et al., J Infect Dis 2010; 202(10):1553-6

7. Most latently infected and productively infected cells are in lymphoid tissue RT-SHIV infection HAART =Tenofovir/emtricitabine/efavirenz North et al., J Virol 2010; 84(6):2913-22

8. Size of HIV Reservoir correlates with activated CD8+ T cells (in Sigmoid Colon) Seth et al., Mucosal Immunology 2008:1:382-388

9. What is unique about these tissue sites? • Ongoing replication due to • Poor penetration of drugs? • Localised sites of inflammation? • Unique long-lived cells such as macrophages or DCs allowing for cell-cell transmission? • Infection of resting cells?

10. Ex vivo tissue blocks Resting CD4+ T-cell In vitro chemokines Eckstein et al, Immunity 2001; 15: 671; Kreisberg et al., J Exp Med 2006; 203:865; Saleh et al., Blood 2007; 110:416; Cameron et al., Proc Natl Acad Sci 2010 epub Sept 18 Infection of resting T-cells in vitro Unactivated resting cells

11. Multiple chemokines can induce latent HIV infection in resting CD4+ T cells. Cameron et al., Proc Natl Acad Sci 2010; 107(39):16934-9

12. CCR7 + CCL19 Chemokine receptor ligation activates cofilin and actin polymerisation CXCR4 + gp120 Yoder et al Cell 2008 Cameron et al PNAS 2010

13. Chemokine signalling pathways PI3K PI3K

14. Inhibition of Erk1/2, Jnk and NF-kB eliminates integration (ALu-LTR) P38 NFB ERK JNK NFB SP600125 SC-514 Bay 11-7082 CCL19+DMSO PD980509 SB203580 Saleh et al., 5th IAS Conference, Rome, 2011

15. Ex vivo tissue blocks Resting CD4+ T-cell In vitro chemokines Eckstein et al, Immunity 2001; 15: 671; Kreisberg et al., J Exp Med 2006; 203:865; Saleh et al., Blood 2007; 110:416; Cameron et al., Proc Natl Acad Sci 2010 epub Sept 18 Infection of resting T-cells in vitro Unactivated resting cells Dendritic cells

16. Dendritic cells facilitate latent HIV infection Evans et al., unpublished

17. maintenance of HIV latency

18. Negative regulators activation EM differentiation Homeostatic proliferation What is the fate of a latently infected cell?

19. Number of latently infected cells is correlated with proliferation: role of IL-7 Chomont et al., Nat Med 2009

20. p=0.03 Int HIV DNA per mL of blood Int HIV DNA per 106 CD4 T cells 800 2000 600 1500 400 1000 200 500 0 Day 0 Day 28 0 Day 0 Day 28 IL-7 increases proliferation leading to expansion of HIV DNA in vivo HIV infected subjects under suppressive HAART received IL-7 injections (ACTG5214, blind study). Vandergreeten 6th IAS conference on HIV Pathogenesis, Treatment and Prevention, Rome, 2011

21. Negative regulators activation EM differentiation Homeostatic proliferation What is the fate of a latently infected cell?

22. 600 400 Mock p24 (pg/mL) a-PD-1 blocking Ab 200 Isotype control 0 Donor A Donor B Donor C Da Fonesca et al., HIV Reservoir Workshop, Vienna, July 2010 PD-1 hi cells are enriched for latentlly infected cells Chomont et al., Nature Med 2009;15: 893

23. Negative regulators activation EM differentiation Homeostatic proliferation What is the fate of a latently infected cell? IL-15

24. role of the adaptive immune response

25. Inverse relationship between HIV-specific CD4+ T-cells and HIV DNA N=66; long term non progressors, no ARV Martinez et al., J Infect Dis 2001; 191:2053–63

26. HLA type influences size and distribution of latently infected cells Descours; Avettand-Fenoel Submitted

27. Summary • Latency can be established in multiple T-cell subsets • High concentration of latently infected cells in tissue including GI tract and lymphoid tissue • Chemokines and dendritic cells play a key role in establishing latency in resting T-cells • Maintenance of latency can occur by • Homeostatic proliferation (IL-7) • Negative regulators of T-cell activation (PD1) • Adaptive immune response likely important

28. Negative regulators Anti-PD-1 minocycline activation vaccination EM Chemokine antagonists differentiation Auranofin IL-15 Homeostatic proliferation Anti-IL7 What is the fate of a latently infected cell?

29. Department of Medicine, Monash University, Melbourne Paul Cameron Suha Saleh Vanessa Evans Nitasha Kumar Ajantha Solomon Georgina Sallman Fiona Wightman Westmead Millenium Research Institute, Sydney Tony Cunningham Andrew Harman VGTI Florida, Port St Lucie, FL Rafick Sekaly Elias Haddad Genevieve Boucher Nicolas Chomont Hopital Pitie Salpatriere, Paris Brigitte Autran Benjamin Descours Acknowledgements