Target Cells for HIV-1/SIV Infection in Mucosal Tissue

The mucosal surfaces of the genital and gastrointestinal tracts are the routes by which HIV-1 is acquired, excluding persons infected parenterally. Identification of the mucosal target cells and the receptors by which HIV-1 enters these cells is fundamental to elucidating the biology of HIV-1 transmission. The mucosal target cells include epithelial cells, dendritic cells, Langerhans cells, CD4+ T-cells, macrophages and even mast cells, but the contribution of each cell type is highly dependent on the mucosal surface - genital versus gastrointestinal. Importantly, mucosal target cells may also play key roles in the immunobiology and latency of HIV-1 infection. Given the pivotal role of mucosal cells in HIV-1 transmission and pathogenesis, an effective vaccine to bring the HIV-1 pandemic under control must be effective at the level of the key target cells in both the genital and gastrointestinal mucosae.