Recombinant human gamma interferon enhances in vitro activation of lymphocytes isolated from patients with acquired immunodeficiency syndrome.

Decreased responses to antigens and lectins are a characteristic feature of peripheral blood lymphocytes isolated from patients with the acquired immunodeficiency syndrome (AIDS). The in vitro addition of recombinant gamma interferon (IFN-gamma) to cultures of peripheral blood lymphocytes obtained from patients with AIDS resulted in an augmented proliferative response [( 3H]thymidine uptake) to phytohemagglutinin (PHA) and an enrichment in CD4+ and CD8+ T lymphocytes. In AIDS cultures stimulated with PHA, IFN-gamma increased the release of T-cell growth factors and enhanced the expression of interleukin-2 receptors on activated lymphocytes. Responsiveness to PHA was augmented, albeit to a lesser extent, by IFN-gamma in cultures derived from normal donors. Proliferation to microbial antigens including herpes simplex virus, cytomegalo virus, and Candida albicans was increased by IFN-gamma in cultures established from a group of AIDS patients with Kaposi's sarcoma who had no history of opportunistic infection.