Effect of Seminal Fluid on the Colon Wall; Implications for HIV Transmission

Design of effective rectal microbicides to prevent HIV infection requires an understanding of rectal HIV transmission and the location within the lower gastrointestinal (GI) tract (luminal and mucosal) of HIV (cell-free and cell-associated) following exposure to infected seminal fluid. These basic details of HIV transmission have yet to be determined in human subjects, yet they are essential to select microbicide candidates if they are to be rationally designed to achieve effective concentrations at sites of HIV transmission. Rational development of a rectal microbicide also requires an understanding of those factors that may contribute to colonic mucosal injury - potential confounders of microbicidal effect. Such factors include exposure to seminal fluid which has been shown in animal and in vitro studies to cause histologic and permeability changes that might facilitate HIV transmission.