HIV ANTIGEN-REACTIVE T-CELLS DETECTED BY ANTIGEN-INDUCED INTERFERON-GAMMA SECRETION

The T cell repertoire to human immunodeficiency virus (HIV) was studie d in HIV-infected patients of different clinical stages by the detecti on and enumeration of cells that secreted interferon gamma(IFN-gamma) in short-term cultures of blood mononuclear cells after stimulation in vitro with the HIV recombinant antigens pB1, p121, p24-15, gp160(bac) , and the HIV V3 loop peptide. T cell reactivities to cytomegalovirus (CMV) and Mycobacterium tuberculosis-purified protein derivative (PPD) were examined in parallel. Among 29 patients with HIV infection, 48% had blood cells recognizing one or more of the five HIV antigens. The mean numbers of HIV antigen-reactive T cells varied between 1/similar to 6000 blood cells for pB1 and 1/similar to 20,000 cells for p24-15. None of the five HIV antigens studied was identified as an immunodomin ant T cell epitope in HIV infection. T cells from 20% of the patients responded to all five HIV antigens in parallel, but the antigen prefer entially recognized varied from patient to patient. Those with more ad vanced disease had a, tendency to lower numbers of HIV antigen-reactiv e T cells. Most HIV-infected patients had both CMV- and PPD-reactive T cells, but numbers were significantly lower in more advanced disease. It should be possible to adopt the present method to evaluate fine sp ecificities of the T cell repertoire to other antigens and to study th e involvement of other cytokines besides IFN-gamma, for example, the T (h)2 cell-related cytokine interleukin 4.