Dendritic Cell Amplification of HIV Type 1-Specific CD8+ T Cell Responses in Exposed, Seronegative Heterosexual Women

In the Heterosexual AIDS Transmission Study (HATS), the frequency of high-risk sexual activity and viral load in the seropositive partner were shown to correlate with HIV-1 transmission. However, these parameters could not account for the status of some exposed, seronegative (ESN) individuals who remained uninfected despite years of exposure. To test the hypothesis that antiviral immune responses are a correlate of nontransmission in this cohort, we developed two sensitive methods for assessing HIV-1-specific humoral and cell-mediated responses. To quantify T cell responses, autologous mature dendritic cells (DCs) were used as antigen-presenting cells to elicit HIV-1-specific IFN-γ production by ELISPOT. Antibody responses to HIV-1 gp120 were assessed by combination immunoprecipitation-Western blot (IP-WB). Previous studies of this cohort, using limiting dilution analysis, did not reveal HIV-1-specific cytotoxic T lymphocyte activity. However, when autologous DCs were used to present HIV-1 antigens, T cel...