DIFFERENT EFFECT OF 1,25-DIHYDROXYVITAMIN-D3 ON REPLICATION OF MYCOBACTERIUM-AVIUM IN MONOCYTE-DERIVED MACROPHAGES FROM HUMAN IMMUNODEFICIENCY VIRUS-INFECTED SUBJECTS AND HEALTHY CONTROLS

Mycobacterium avium complex (MAC) is the most common cause of dissemin ated bacterial infection in patients with acquired immune deficiency s yndrome (AIDS) and macrophage dysfunction is important both in the pat hogenesis of AIDS- and MAC-infection. 1,25-Dihydroxyvitamin D3 (1,25D) , the active metabolite of vitamin D, has a number of effects on cell types of the immune system including monocytes/macrophages. The presen t study was designed to investigate whether 1,25D supplementation in v itro could modulate MAC replication in macrophages from HIV-infected p atients. It was therefore of particular interest to examine whether th e effect of 1,25D differs between cells from HIV-infected patients and healthy control subjects. After 3 and 7 days of infection, 1,25D supp lementation increased numbers of bacteria in cells from control subjec ts. In contrast, there was no change or even a decrease in numbers of bacteria in cells from HIV-infected patients. These findings suggest t hat HIV infection may significantly modulate the macrophage response t o 1,25D stimulation, and that 1,25D may have inhibitory effects on MAC replication in macrophages from HIV-infected patients. (C) 1998 Elsev ier Science B.V. All rights reserved.