INTERACTION WITH HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 MODULATES INNATEEFFECTOR FUNCTIONS OF HUMAN MONOCYTES

The effect of human immunodeficiency virus (HIV) type 1 on human monon uclear phagocyte effector functions in response to infection with bact eria of the Mycobacterium avium-intracellulare complex (MAC) was inves tigated. The results showed that interaction of HIV-1 or its constitue nts with CD4 expressed in the monocyte membrane led to substantial imp airment of monocyte capacity to restrict the intracellular growth of M AC. This was accompanied by substantially decreased production of tumo r necrosis factor-alpha by HIV-1-exposed and MAC-infected monocytes. H owever, productive HIV-1 infection of monocytes was not required to in duce the observed effects. These studies suggest that HIV-1 may interf ere with innate mononuclear phagocyte function. This may be of physiol ogic importance in the late stages of AIDS, when an impaired T cell im munity can no longer provide proper immune-activating signals, and may help to explain the undue susceptibility to MAC infections in these p atients.