A human immunodeficiency virus (HIV)-inducing factor from the female genital tract activates HIV-1 gene expression through the KB enhancer

Virus-enhancing factors present in the female genital tract may influence the transmission of human immunodeficiency virus type 1 (HIV-1). Previously, the presence of a heat-stable soluble factor in the cervicovaginal lavage (CVL) fluid of both HIV-infected and -uninfected women that induces HIV-1 expression in T cells and monocytes was reported. Now this CVL factor was shown to increase HIV-1 gene expression through the activation of the kappa B enhancer in the viral long terminal repeat (LTR). DNA binding studies, together with functional studies using mutant LTR reporter constructs, indicate the requirement for an NF-kappa B-dependent pathway in the CVL-mediated activation of HIV-1 expression. CVL samples that activated HIV-1 expression also stimulated AP-l-dependent transcription These data demonstrate that an HIV-inducing factor, distinct from heat-labile cytokines, present in the female genital mucosa can activate AP-1 and NF-kappa B and increase HIV-I gene expression through the KB enhancer, possibly contributing to HIV-1 transmission.