Stoddard E, Ni H, Cannon G et al. J Virol 2009;83:8596–603.
In this report focusing on the sexual transmission of HIV-1, Stoddard and colleagues characterized a significant role for a receptor present on human vaginal and cervical tissue – the human scavenger receptor gp340.
Reproductive tract cells including the mucosal columnar epithelia of the endocervix and uterus, and the stratified squamous epithelia of the vagina and ectocervix, together form a cellular barrier that segregates the site of semen deposition from the first immune cells infected by simian immunodeficiency virus (SIV) and HIV – the Langerhans cells, submucosal CD4+ T cells, and dendritic cells. Previous studies have shown that syndecans including heparin sulfate proteoglycan (HSPG) moieties expressed on the luminal membranes contribute to the transport of virus through these barriers via a mechanism known as direct transcytosis (for example, [1,2]). These studies have shown that gp340 binds HIV-1 expressed by the genital tract and promotes infection of macrophages. After ligand binding, gp340 transits between the extracellular membrane and intracellular endosome.