Effect of interleukin (IL)-15 priming on IL-12 and interferon-gamma production by pathogen-stimulated peripheral blood mononuclear cells from human immunodeficiency virus-seropositive and -seronegative donors.

Hypoproduction of the cytokines interleukin (IL)-12 and interferon (IFN)-gamma is thought to contribute to the impaired immunity seen in human immunodeficiency virus (HIV)-infected persons. The effects of priming with IL-15 on the production of IL-12 and IFN-gamma by stimulated peripheral blood mononuclear cells (PBMC) from HIV-seronegative and -seropositive donors were studied. Stimuli included 3 pathogens that commonly infect HIV-positive persons-Cryptococcus neoformans, Candida albicans, and Mycobacterium tuberculosis-plus Staphylococcus aureus. Following IL-15 priming of HIV-negative PBMC, pathogen-stimulated IL-12 and IFN-gamma production increased 5-58-fold. However, for the HIV-positive PBMC, IL-15 priming did not lead to significant increases in pathogen-stimulated IL-12 production and caused only modest increases in IFN-gamma production. These data suggest that IL-15 alone may be insufficient to correct the defect in IL-12 and IFN-gamma production in HIV-positive persons.