Cervicovaginal secretory antibodies to human immunodeficiency virus type 1(HIV-1) that block viral transcytosis through tight epithelial barriers inhighly exposed HIV-1-seronegative African women

Antibodies to human immunodeficiency virus (HIV) of the IgA, IgG, and IgM i sotypes and high levels of the HIV suppressive beta -chemokine RANTES (regu lated on activation, normally T cell expressed and secreted) were found in the cervicovaginal secretions (CVSs) of 7.5% of 342 multiply and repeatedly exposed African HIV-seronegative female sex workers. The antibodies are pa rt of a local compartmentalized secretory immune response to HIV, since the y are present in vaginal fluids that are free of contaminating semen. Cervi covaginal antibodies showed a reproducible pattern of reactivity restricted to gp160 and p24. Locally produced anti-env antibodies exhibit reactivity toward the neutralizing ELDKWA epitope of gp41. Study results show that ant ibodies purified from CVSs block the transcytosis of cell-associated HIV th rough a tight epithelial monolayer in vitro. These findings suggest that ge nital resistance to HIV may involve HIV-specific cervicovaginal antibody re sponses in a minority of highly exposed HIV-seronegative women in associati on with other protecting factors, such as local production of HIV-suppressi ve chemokines.