In vitro modulation of cytokine production by lymphocytes in human coccidioidomycosis

The modulation of the cytokine response to coccidioidal antigen by lymphocytes from donors with coccidioidomycosis was examined. In initial experiments, samples from 13 healthy immune donors and seven donors with active coccidioidomycosis anergic to the coccidioidal antigen T27K were assessed for CD3 lymphocyte expression of intracellular IFN-γ using whole blood analysis. Addition of 10ng/ml of recombinant IL-12 significantly increased response to T27K among immune and anergic subjects (p<0.05), but the percent of cells expressing IFN-γ was still significantly greater for immune subjects. Among immune donors, the percentage of CD3 lymphocytes expressing IFN-γ was significantly reduced with the addition of 10ng/ml of recombinant IL-4, IL-10, TGF-β, or their combination (for all, p<0.05). Among anergic donors, addition of 10ng/ml of anti-IL-10 significantly increased IFN-γ production (p<0.05), but addition of anti-IL-4 or anti-TGF-β did not. Among immune donors, the percent of both CD3 lymphocytes and NK cells expressing IFN-γ after 24h of T27K was increased above control (p<0.05), while the percent of NK cells producing TNF-α in response to T27K was not greater than control. Depletion of NK cells from peripheral blood mononuclear cells resulted in significant increases in TNF-α and IL-10 (for both, p<0.05) but resulted in no significant decrease in IFN-γ or IL-2. These data demonstrate a differential response to stimulation with the coccidioidal antigen T27K among donors with coccidioidomycosis that can be manipulated by cell type and cytokine environment.