Vertical transmission of HIV: Parameters which might affect infection of placental trophoblasts by HIV-1: A review

PROBLEM: To understand the mechanisms preventing and/or facilitating maternofetal transmission of human immunodeficiency virus (HIV)-1 across the placenta during pregnancy. METHODS OF STUDY: Current experimental data were reviewed. RESULTS AND CONCLUSIONS: The data about the production of cytokines by placental cells and explants, taken together with information indicating selective passage of certain HIV-1 variants across the placental trophoblast, suggest an intricate regulatory network operating at the fetomaternal interface. The data show a differential differentiation of early and late trophoblasts, as far as HIV entry routes are concerned. We believe this explains the relative predominance of the early infection window, as far as in utero infection is concerned. Whether such a differentiation state can be transiently induced on term placental trophoblasts by several differentiation agents, including cytokines, is being investigated. Whatever the results may be, it is obvious that infection of placental cells is an excellent model of passage infection by HIV of/through a mucosal barrier.