IFN-GAMMA RESTORES HIV-SPECIFIC AND NON-HIV-SPECIFIC CELL-MEDIATED IMMUNE-RESPONSE IN-VITRO AND ITS ACTIVITY IS NEUTRALIZED BY ANTIBODIES FROM PATIENTS WITH AIDS

The addition of IFN-gamma to cultures of peripheral blood mononuclear cells (PBMCs) obtained from asymptomatic HIV-infected patients increas ed cell proliferation in response to HIV envelope synthetic peptides ( Env), influenza A virus (VIRUS), and allogeneic lymphocytes (ALLO) but not to phytohaemagglutinin (PHA) stimulation. F(Ab)(2) fragments of I gG purified from the sera of HIV-seropositive patients specifically in terfered with IFN-gamma-induced cell proliferation in response to reca ll antigens. Neutralization of the lymphokine activity was found to be sustained by specific IFN-gamma antibodies. Data obtained demonstrate that IFN-gamma can restore the cell-mediated immunity of a number of asymptomatic HIV+ individuals in vitro, while IFN-gamma antibodies pre sent in sera of patients with AIDS interfere with the activity of the lymphokine.