ENHANCED SUSCEPTIBILITY OF BLOOD MONOCYTES FROM PATIENTS WITH PULMONARY TUBERCULOSIS TO PRODUCTIVE INFECTION WITH HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1

Blood monocytes from patients with active pulmonary tuberculosis and a ge-matched healthy purified protein derivative-reactive donors were in fected with human immunodeficiency virus type 1 (HIV-1)JR-FL in vitro to assess their susceptibility to productive infection by HIV-1. HIV-1 p24 levels (enzyme-linked immunosorbent assay) in supernatants of inf ected cells from patients with tuberculosis, albeit variable, were sig nificantly higher at days 10-20 of culture; the maximum levels of p24 antigen were greater in supernatants of HIV-1-infected monocytes from patients than maximum levels for controls (p <0.05). The maximum incre ment in p24 levels for patients. also exceeded that for controls (p <0 .05). Entry of HIV-1 and/or initiation of reverse transcription, measu red by polymerase chain reaction using HIV-1 R/U5 primer pairs, was va riable and low in infected monocytes from both patients and controls, and did not correlate with HIV-1 p24 levels. The frequency of infected cells as assessed by endpoint dilution viral cultures was similar for both groups. Therefore, blood monocytes from patients with active tub erculosis can develop a highly productive infection with HIV-I that do es not appear to be due to enhanced HIV entry or higher frequency of i nfected cells. The enhanced susceptibility may result directly from ac tivation of monocytes by exposure to Mycobacterium tuberculosis and it s products in situ.