In vitro effect of transforming growth factor-beta on progression of HIV-1 infection in primary mononuclear phagocytes

In vitro-differentiated monocytes can be infected with the monocytotropic isolate of HIV-1/ADA. The infection is characterized by formation of giant cells and production of virus that can be found in cell supernatants or cell-associated. In this study, we demonstrate that the above described parameters of infection can be enhanced by a factor present in acidified M phi supernatants, suggesting that it might be transforming growth factor beta-1 (TGF-beta 1). When recombinant or purified TGF-beta were examined, similar activities were detected. This effect apparently is not because of changes in the cellular phenotype that could favor infection. The effect of TGF-beta is exerted on cells once infection is established or on cells with active virus production. The activity can be also demonstrated using U-937 cells.