Transmission of HIV-1 by primary human uterine epithelial cells and stromal fibroblasts.

Women can become infected with human immunodeficiency virus type 1 (HIV-1) after the heterosexual transmission of virus from an infected male partner. To understand the events that result in transmission of HIV-1 across the female reproductive tract, we characterized the life-cycle events of HIV-1 in primary cultures of human uterine epithelial cells and stromal fibroblasts. Epithelial cells and stromal fibroblasts released virus particles after exposure to either X4- or R5-tropic strains of HIV-1. Virus released by these cells was able to infect CD4(+) T cells. When exposed to an X4-tropic strain of HIV-1, these cells supported HIV-1 reverse transcription, integration, and viral DNA transcription. When exposed to an R5-tropic strain, however, these cells released unmodified virus. These data suggest that uterine cells are targets for productive infection with X4-tropic strains and release unmodified R5-tropic viruses that would then be able to infect submucosal target cells, including T cells and macrophages.