Expanded memory CD4+ T Cells in the fetal and the infant Gut; a mucosal route for mother-to-child transmission of HIV-1

Background Cord blood-derived CD4+ T cells have a naive phenotype and do not express CCR5, the mandatory co-receptor for transmitted HIV-1 R5 strains in infants. This leaves the question unanswered: what are the target cells for MTCT of HIV-1 and where do they reside? We hypothesized that in infant mucosal tissues, CD4+CCR5 + T cells may be present to facilitate mucosal transmission of HIV-1.