Innate immune factors associated with HIV-1 transmission

Relatively little is known with regards to the mechanisms of HIV-1 transmission across a mucosal surface and more specifically what effects host factors have on influencing infection and early viral dissemination. The purpose of this review is to summarize which factors of the innate immune response can influence mucosal transmission of HIV-1. A large array of cell types reside at the mucosal surface ranging from Langerhans cells, dendritic cells, macrophages as well as CD4⁺ lymphocytes, all of which interact with the virus in a unique and different way and which can contribute to risk of HIV-1 transmission. Numerous factors present in bodily secretions as well as the carrier fluids of HIV-1 (breast milk, vaginal secretions, semen and intestinal mucus) can influence transmission and early virus replication. These range from cytokines, chemokines, small peptides, glycoproteins as well as an array of host intracellular molecules which can influence viral uncoating, reverse transcription as well as egress from the infected cell. Better understanding the cellular mechanisms of HIV-1 transmission and how different host factor can influence infection will aide in the future development of vaccines, microbicides, and therapies