Objective: To examine the effects of soluble factors secretedby human papillomavirus (HPV)-associated cells on humanimmunodeficiency virus (HIV) expression.Methods: Supernatants collected from cultured cervicalbiopsies and cervical cancer cell lines, and HPV-immortalized and normal keratinocytes were tested for theability to induce HIV p24 production in two cell lines thatcontained latent HIV (the U1 monocytic line and the ACH-2T cell line). Levels of HIV p24 were measured by enzyme-linked immunosorbent assay (ELISA). Culture supernatantswere also assayed for the inflammatory cytokines interleu-kin 6, tumor necrosis factor, and interleukin 1bby ELISA.Results: Supernatants from all epithelial cells tested up-regulated HIV p24 expression in the U1 line but not in theACH-2 cells. Only differentiated normal keratinocytes in-duced p24 production by ACH-2 cells. Neutralization of thecytokines, particularly interleukin 6, partially reduced thelevel of HIV-inducing activity in the culture supernatants.Additionally, cervical biopsies from HIV-infected womencultured in vitro also were able to induce HIV in U1 cells butnot ACH-2 cells.Conclusions: Our results suggest that HPV infection of thecervix might influence HIV pathogenesis by inducing theproduction of immune and inflammatory factors that en-hance HIV expression.