INFECTION OF HUMAN MONOCYTES WITH MYCOBACTERIUM-TUBERCULOSIS ENHANCESHUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 REPLICATION AND TRANSMISSION TO T-CELLS

Mycobacterium tuberculosis and human immunodeficiency virus type 1 (HI V-1) are virulent intracellular pathogens that invade and multiply wit hin macrophages. The effect of M. tuberculosis on HIV-1 infection and replication was analyzed in vitro using human monocyte-derived macroph ages (MDM) isolated from peripheral blood mononuclear cells by counter current centrifugal elutriation. Preinfection of MDM with M. tuberculo sis followed by HIV-1 infection resulted in an increase in p24 release , reverse transcriptase activity, and infective virus production. In c ontrast, no increase in HIV-1 production was observed when MDM were in fected with Mycobacterium avium complex or heat-killed M. tuberculosis . Coinfected MDM were potent stimulators of T cell proliferation, whil e HIV-1-infected MDM failed to present exogenous tuberculin to T cells . Furthermore, coinfected MDM showed an increased capacity to transmit HIV-1 to activated T cells., These results suggest that M. tuberculos is infection can both up-regulate HIV-1 infection and replication with in MDM and increase the efficiency of virus transmission from infected MDM to T cells.