Evaluation of Candida species-specific T cell immune response in human
peripheral blood mononuclear cells
Non-albicans Candida (NAC) species are emerging causes of all Candidemia
infections, but relatively less is known about the immune responses
induced by these species. In this study, we compared the ability of
cytokine production by human peripheral blood mononuclear cells (PBMC)
upon stimulation with different Candida species. We measured secreted
cytokines by ELISA and checked the functional profile of T cell
responses at a single-cell level by multi-color flow cytometry
technique. Though there was a differential expression of cytokines
against the Candida species, a significant difference was observed in
the levels of IFN-γ, TNF-α, IL-10, IL-12p40, and IL-23
(p<0.05) between the Candida species. There is a significant
difference was observed between C. albicans and C. glabrata (p-0.026) in
the levels of TNF-α. C. glabrata showed significant difference with C.
albicans, C. parapsilosis and C. krusei in the levels of IL-10. Despite
the percentages of CD4+ and CD8+ expressing Th1, Th2 and Th17 cytokines
being higher in stimulated PBMC, none of the Candida species showed
significant differences. The levels of secreted IL-17A and IL-23 were
consistently lower in Candida species regardless of the stimulus used.
Here we showed the differential regulation of the Th1, Th2 and Th17
during Candida species stimulation of the immune system in vitro. Our
results also indicate that while C. albicans induces a Th1 response, C.
glabrata induces Th2 cellular responses. This study could enhance our
knowledge of differential immune responses induced by Candida species
and may help to develop immunotherapeutics and vaccines.