HIV-1 down-modulates γ signaling chain of FcγR in human macrophages: A possible mechanism for inhibition of phagocytosis

Abstract

HIV-1 infection impairs a number of macrophage effector functions, thereby contributing to development of opportunistic infections and the pathogenesis of AIDS. FcγR-mediated phagocytosis by human monocyte-derived macrophages (MDM) is inhibited by HIV-1 infection in vitro, and the underlying mechanism was investigated in this study. Inhibition of phagocytosis directly correlated with the multiplicity of HIV-1 infection. Expression of surface FcγRs was unaffected by HIV-1 infection, suggesting that inhibition of phagocytosis occurred during or after receptor binding. HIV-1 infection of MDM markedly inhibited tyrosine phosphorylation of the cellular proteins, which occurs following engagement ..