Anti-fungal and cytokine producing activities of CD8 + T lymphocytes from HIV-1 infected individuals

Lymphokine activated killer (LAK) cells are capable of killing not only malignant cells but also hyphal form of Candida albicans in vitro. When peripheral blood mononuclear cells (PBMC) from normal healthy donors were cultured for 72-96 hrs with 1,500 international unit (IU)/ml interleukin-2 (IL-2), marked LAK activity was induced. However, even prior to IL-2 activation, PBMC isolated from some normal subjects and those from almost all individuals who are infected by human immunodeficiency virus type 1 (HIV-1) exhibited significant levels of anti-fungal activity. Such pre-activation ("in situ") antifungal activity of PBMC decreased during the initial 48 hrs of IL-2 activation. PBMC from HIV-1 seropositive subjects showed higher levels of "in situ" anti-fungal activity than normal PBMC did. After a decline of "in situ" activity during the initial 48 hours, LAK activity gradually increased and reached near maximal levels by day 4 and remained more or less constant until day 6. No significant difference was observed between the LAK activity of normal and HIV-1(+) PBMCs on days 4-6. In IL-2 activated normal and HIV-1(+) PBMC cultures, both CD4 and CD8 T cells produced IL-2, INF-gamma as well as TNF-alpha. Production of IL-2 by both CD4 and CD8 T cells was suppressed in HIV-1(+) PBMC cultures, but no significant suppression of INF-gamma production was noted. Meanwhile, TNF-alpha production by CD4 was very much suppressed but no significant changes in TNF-alpha production by CD8 T cells was noted in HIV-1(+) PBMC cultures.