Absence of anti-HIV activity in vaginal epithelial secretions. Conditioned media were recovered after 48 hrs of culture and analyzed for inhibitory activity against BaL (a, c) and IIIB (b, d), a CCR5 and CXCR4 viral strain, respectively. Conditioned media were diluted 1:8 in complete media and incubated with virus at an multiplicity of infection of 1, for 1 hr at 37°C prior to incubation with TZM-bl cells. Vaginal epithelial cells were treated for 48 hrs with 5 × 10−8 M estradiol (E2) (a, b), and a panel of selective estrogen response modulators including Y134, PHTTP, ICI and tamoxifen (Tx) at 1 × 10−7 M (c, d). Each symbol on the graph represents a single patient sample. *P < 0.05 with respect to virus alone (BaL or IIIB).