HIV-specific T helper responses and frequency of exposure among HIV-exposed seronegative female sex workers in Abidjan, Cote d'Ivoire

Background. The characteristics of human immunodeficiency virus (HIV) exposure that determine the in-duction of HIV-specific T cells and, in particular, T helper cells are not well understood. Methods. HIV-1 Gag- and Env-specific T helper cells were analyzed by use of an interferon (IFN)–g enzyme-linked immunosorbent spot (ELISPOT) assay and by use of IFN-g secretion flow cytometry. Responses among HIV-exposed seronegative (ESN) female sex workers (FSWs) were compared with responses among HIV-sero-positive FSWs and HIV-seronegative female blood donors from Abidjan, Côte d’Ivoire. Results. Low-level ELISPOT responses were detected in 8 (20%) of 40 ESN FSWs. All of 25 HIV-seropositive FSWs had high-level ELISPOT responses. HIV-specific CD4+ T cells and, occasionally, CD8+ T cells were detecte