1. Washington D.C., USA, 22-27 July 2012www.aids2012.org Induction and Maintenance of HIV-1-Specific Immune Responses in Exposed Sero-negative (ESN) Women of Sero-discordant Couples from Southern India Suniti Solomon 1, K.G. Murugavel 1, R.Vignesh 1, D. Bella 1, R. Shoba 1, S. Poongulali 1, N. Kumarasamy 1, A. Landay 2, L. Baum 2, Sunil S. Solomon 1,3, C.R. Swathirajan 1, P. Balakrishnan 1, Susan Cu-Uvin 4, K.H. Mayer 5, B.L. Shacklett 6 1 YRG CARE, Chennai, India; 2 Rush University, Chicago, IL, USA; 3 Johns Hopkins School of Medicine, MD, USA; 4 Brown University, Providence, RI, USA; 6 Beth Israel Deaconess Hospital, MA, USA; 6 UC Davis, Davis, CA, USA.

2. Washington D.C., USA, 22-27 July 2012www.aids2012.org Objective o To determine the breadth and persistence of HIV-1 specific cytotoxic T lymphocyte (CTL) responses in blood and cervical mucosa of ESN women. Study Population o 30 ESN women provided samples at baseline and at least one follow up visit (3 rd,6 th month). o Sero-concordant couples (n=17) and low-risk seronegative women (n=30) provided samples only at baseline and were included as controls. Methods o Peripheral blood mononuclear cells (PBMC) and mucosal mononuclear cells (MMC) were stimulated with HIV-1 Gag and Env (Clade C) and IFN-g production was measured by Intracellular cytokine staining (ICS) assay. o The flow data were analyzed using FlowJo software.

3. Washington D.C., USA, 22-27 July 2012www.aids2012.org Results BaselineFollow-up Study cohortPBMCMMCPBMCMMC ESN women 2 /30 (7%) Env responses 3/17 (18%) Env / Env+ Gag 3/17 (18%) Env responses 1/7 (14%) Env and Gag HIV-1 concordant women 8/17 (47%) Gag responses 2/5 (40%) Env responses --- Low risk women0/300/25--- Conclusion o These findings confirm that HIV-specific T-cell responses can be detected in PBMC and MMC from ESN women. o In ESN women, the PBMC responses were exclusively directed against Env. o One out of 4 ESN women continued to show positive responses upon longitudinal follow-up.