The effect of infection with human immunodeficiency virus on the anticryptococcal activity of lymphocytes and monocytes.

The effect of infection with human immunodeficiency virus (HIV) on the capacity of human lymphocytes and monocytes to inhibit and kill Cryptococcus neoformans in an 18-h assay was examined. In vitro infection of the Jurkat human T cell line with each of 3 HIV strains caused significant loss of anticryptococcal activity, which peaked 3-4 weeks after HIV infection. Lymphocytes from HIV-seropositive and -seronegative persons had similar activity, even if highly enriched for CD4 cells. The activity of lymphocytes from both seropositive and seronegative donors was increased by culture with interleukin-2 and phytohemagglutinin, but only activated lymphocytes from seronegative donors caused a reduction in C. neoformans colony-forming units. Both peripheral blood mononuclear cells and monocytes from HIV-positive persons had significantly reduced antifungal activity compared with cells from seronegative donors. Thus, under defined conditions, infection with HIV can impair the anticryptococcal activity of both lymphocytes and monocytes. Such qualitative defects may contribute, together with CD4 lymphocytopenia, to the particular susceptibility of HIV patients to cryptococcosis.