PRODUCTIVE AND PERSISTENT INFECTION OF HUMAN THYMIC EPITHELIAL-CELLS IN-VITRO WITH HIV-1

Infection with HIV-1 results in a disruption of the thymic microenviro nment and the presence of HIV-1 in thymic epithelial cells has been de monstrated in vivo. In the present study, we examined the susceptibili ty of a highly enriched culture of thymic epithelial cells (TEC) to in fection in vitro by HIV-1 laboratory strains and primary isolates. Rep lication in TEC is shown to depend on the virus and on the expression of CD4 molecules that are found to be expressed at a low density on th e plasma membrane. Our results are consistent with infection of TEC co ntrolled by the efficiency of the interactions between the envelope gl ycoprotein of the virus and the cell surface molecules. As a consequen ce, certain HIV-1 viruses induce a productive and persistent infection in TEC without damaging the cells. Altogether these results support t he idea that TEC may act as a reservoir for HIV-1 in the thymus but ar e probably destroyed by an indirect mechanism involving infection of t hymocytes. (C) 1996 Academic Press, Inc.