1. HIV-1 TRANSMISSION FROM SEMEN TO CERVICO-VAGINAL TISSUE EX VIVO Andrea Introini 1, Christophe Vanpouille 1, Andrea Lisco 1, Jean-Charles Grivel, Arshi Munawwar 2, Sarman Singh 2, and Leonid Margolis 1 1 National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States, 2 All India Institute of Medical Sciences, New Delhi, India

2. Vaginal intercourse is the main route of HIV-1 sexual transmission

3. HIV- infection of human cervico-vaginal tissue ex vivo rectosigmoid tonsillar exocervical HIV-1 in seminal fluid

4. Semen and blood from 50 HIV-1- infected and 33 HIV-uninfected men

5. SEMEN AND BLOOD ARE SEPARATE IMMUNOLOGICAL COMPARTMENTS IL-1α IL-1β IL-6IL-7IL-8 IL-15 IL-2 Eotaxin IFN-γ IL-16MIG IP-10 MCP-1 MIP-1α MIP-3α MIP-1β SDF-1βTNF-α TGF-β GM-CSF SemenBlood Semen: Blood plasma ratio (S:B ratio) HIV-1-UNINFECTED INDIVIDUALS

6. ( HIV-1-uninfected ) seminal plasma blood plasma The 2-way hierarchical cluster analysis confirms that blood and semen have 2 distinct cytokine profiles Cytokine levels: high; low IL  IL1-  IL-7 MCP-1 IP-10 IL-8 MIG MIP-3  SDF-1  IL-6 TGF-  IL-15 IL-1  MIP-1  GM-CSF IL-2 IGN-  IL-16 Eotaxin MIP-1  TNF- 

7. 20 correlations Correlations between cytokine levels in seminal plasma HIV - HIV + -0.25 ≤  ≤ -0.5 +0.5 ≤  ≤ +0.7  ≥ +0.7 +0.25 ≤  ≤ +0.5 No correlation -0.5 ≤  ≤ -0.7  ≥ -0.7 HIV¯ 71 correlations

8. HERPESVIRUSES REACTIVATION IN SEMINAL PLASMA HIV-1-infected % of positive samples 40 20 0 60 80

9. 1 2 3 4 5 6 7 8 9 CMV 1 2 3 4 5 6 EBV Viral load [log 10 copies/mL] bloodsemenbloodsemen CMV and EBV seminal shedding occurs in absence of plasma viremia in 75 and 54% of the patients, respectively EBV and CMV reactivation is compartmentalized

10. IL-7 is increased in semen of chronically HIV-1-infected individuals IL-7 (pg/ml) BloodSemen

11. IL-7 IL-7 role in HIV-1 transmission to cervico-vaginal tissue ? IL-7 Thymus Naïve T-cell Memory T-cell Stromal cell  Survival  Proliferation

12. HIV-1 infection of human tissue ex vivo HIV-1 IL-7 Collagen raft

13. IL-7 enhances HIV-1 replication in cervico-vaginal tissue ex vivo HIV-1 p24 gag (ng/ml) HIV-1 BaL HIV-1 BaL + IL-7 [BaL+IL-7] [BaL]

14. HIV-1 BaL HIV-1 BaL + IL-7 CD4 HIV-1 p24gag Day 6 IL-7 increases the number of HIV-1-infected CD4 T-cells

15. IL-7 decreases HIV-1-induced CD4 T-cells depletion Day 9 - + IL-7 HIV-1 LAI.04

16. IL-7 decreases apoptosis of HIV-1-infected CD4 T-cells IL-7 - + Day 6p=0.0049 HIV-1 LAI.04 p24 gag + APO2.7 + (% of CD4 + )

17. IL-7 decreases apoptosis of HIV-1-infected CD4 T-cells Day 9 Bcl-2 HIV-1 LAI.04 HIV-1 LAI.04 + IL-7 Cumulative distribution function

18. Conclusions Semen and blood are immunologically separate compartment which differ in their cytokine spectra. HIV-1 infection enhances this difference changing the entire pattern of cytokine networks. IL-7 is one of the seminal cytokines greatly upregulated in HIV-1 infected men Upon deposition on cervico-vaginal tissue IL-7 enhances HIV-1 transmission Enhancement of HIV-1 infection is associated with IL-7-mediated prevention of death of HIV-1- infected CD4 T-cells, due to suppression of apoptosis

19. Cervico-vaginal tissue contains much less CD4 T cells than lymph nodes or other lymphoid organs, which may be one of the reasons for a relatively low probability of male-to-female HIV-1 sexual transmission. By preventing the death of the small initial pool of infected cells, IL-7 gives HIV more time to find and infect target cells in cervix/vagina and to start dissemination Concentration of IL-7 in the semen of an HIV-1 infected man may be a determinant of infectiousness for his uninfected female partner. Speculations