HIV Infection in Women: Novel Approaches for Prevention

Human immunodeficiency virus (HIV) infects and destroys lymphocytes, leading to acquired immunodeficiency syndrome. Homosexual men were impacted disproportionately in the early years of the pandemic, while women are now the majority of those infected, making development of anti-HIV treatments and preventatives effective in the female reproductive tract (FRT) imperative. Here, we investigated HIV prevention in women through 1) discovery of antivirals effective in the FRT; and 2) determining a mechanism by which bacterial vaginosis (BV), a disorder of the FRT in which protective Lactobacillus are replaced by BV-associated bacteria (BVAB), increases HIV transmission. We identified a small molecule active against HIV from an extensive compound library and used its structure for an in silico screening, identifying a novel class of HIV inhibitors, Avirulins. Three were active in the low micromolar range and exhibited HIV-1 reverse transcriptase inhibition. Avirulins were not cytotoxic to FRT epithelial cells and maintained activity in human cervicovaginal fluid (CVF). With continued development, Avirulins could serve as additions to antiretroviral therapies or preventatives for the FRT. Next, we hypothesized that BV increases HIV transmission though disruption of the FRT epithelium at the endocervical monolayer, as most FRT lymphocytes reside below the epithelium. We determined that matrix metalloproteinases (MMPs) were secreted by endocervical epithelium in response to BVAB and could depolarize endocervical cell layers. When HIV infected lymphocytes were cocultured with endocervical cell layers, treatment with conditioned media from endocervical cells cocultured with BVAB increased HIV transmigration. Treatment with MMP inhibitors reduced this effect. We demonstrated that CVF from women with BV had greater MMP activity, and presence of certain MMP isotypes in CVF correlated with increased HIV transmigration through the endocervical epithelium. These results propose endocervical disruption by MMPs as a mechanism for BV-induced HIV transmission and suggest the potential of MMP inhibitors as HIV preventatives