Polyclonal expansion of cervical cytobrush-derived T cells to investigate HIV-specific responses in the female genital tract.

Human immunodeficiency virus (HIV) -specific T-cell responses are detectable in the female genital tract of HIV-infected women but little is known about their frequency or the factors that influence their detection. We investigated the feasibility of polyclonal in vitro expansion of cervical cytobrush-derived T cells to investigate HIV-specific responses in the female genital tract in HIV-infected women. Cytobrush-derived cervical cells were isolated from 22 HIV-infected women and expanded with anti-CD3 and recombinant interleukin-2. Cervical T-cell lines were investigated for Gag-specific responses by interferon-gamma ELISPOT and compared with those detected in matched blood samples. Cervical T-cell lines were established from 16/22 (72.7%) participants. Although the absolute number of CD3(+/-) cells recovered after expansion was positively associated with the number of cells isolated ex vivo (P = 0.01; R = 0.62), we observed a significant negative correlation between fold expansion and ex vivo cell number (P = 0.004; R = -0.68). We show that both the magnitude (P = 0.002; R = 0.7) and specific Gag regions targeted by cervical T-cell lines (P < 0.0001; R = 0.5) correlated significantly with those detected in blood. With one exception, cervical interferon-gamma T-cell responses to Gag were detected only in HIV-infected women with blood Gag-specific response > 1000 spot-forming units/10(6) cells. We conclude that cervical Gag-specific T-cell responses in expanded lines are most easily detectable in women who have corresponding high-magnitude Gag-specific T-cell responses in blood.