GROWTH-INHIBITION OF CANDIDA-ALBICANS HYPHAE BY CD8(+) LYMPHOCYTES

We have shown previously that IL-2-activated splenocytes can inhibit t he growth of Candida albicans hyphae in vitro. Herein we demonstrate t hat plastic nonadherent lymphocytes that are CD8(+) mediate the antifu ngal activity. Enrichment for CD8(+) cells markedly enhanced the antif ungal activity of the IL-2-activated lymphocyte population for C. albi cans and the cytotoxic activity of the lymphocytes for an NK-resistant cell line. Depletion of CD8(+) cells reduced the lymphocyte populatio n's antifungal activity and cytotoxic activity for the NK-resistant ce ll line. Enrichment for NK1.1(+) cells markedly reduced the antifungal activity of the lymphocyte population for C. albicans and increased t he cytotoxic activity of the lymphocytes for an NK-sensitive cell line . Depletion of NK1.1(+) cells increased the lymphocyte population's an tifungal activity and cytotoxic activity for the NK-resistant cell lin e. Generation of the antifungal lymphocytes in culture required IL-2 a nd was not replaced with IFN-gamma. These data show that IL-2-activate d CD8(+) T lymphocytes exert the greatest amount of antifungal effect against the hyphal form of C. albicans, whereas IL-2- or IFN-gamma-act ivated NK cells have little or no effect against the hyphae.