Dexamethasone inhibits CD4 T cell deletion mediated by macrophages from human immunodeficiency virus-infected persons

Prednisolone slows the loss of CD4 T cells in individuals with human immuno deficiency virus (HIV) disease and inhibits antigen-induced apoptosis of re cently HIV-infected CD4 cells in vitro. This study investigated whether dex amethasone inhibits the ability of macrophages to delete CD4 T cells via an ti-CD4 antibody or immune-complexed HIV envelope protein gp120. Peripheral blood mononuclear cells from HIV-negative persons were incubated with CD4-r eactive ch412 monoclonal antibody or with gp120/IgG immune complexes and re sident macrophages, with and without dexamethasone. Dexamethasone inhibited CD4 cell deletion in a dose-dependent manner. The deletion of normal CD4 c ells by macrophages from HIV-infected patients also was inhibited by dexame thasone. Furthermore, up-regulation of CD95 expression on T cells exposed t o anti-CD4 and gp120/IgG, which predisposes T cells to CD95-mediated apopto sis, is inhibited by dexamethasone in a dose-dependent fashion. Dexamethaso ne inhibits the macrophage-mediated deletion of CD4 lymphocytes in HIV-infe cted persons.