IL-17-Expressing CD4+and CD8+T Lymphocytes in Human Toxoplasmosis

Abstract

This study aimed to measure the synthesis of Th1 and Th2 cytokines by mononuclear cells after culture with liveT. gondiiand identified Th17 (CD4+) and Tc17 (CD8+) cells in toxoplasma-seronegative and toxoplasma-seropositive parturient and nonpregnant women. Cytometric bead arrays were used to measure cytokine levels (IL-2, TNF-α, IFN-γ, IL-4, IL-5, and IL-10); immunophenotyping was used to characterize Th17 and Tc17 cells, and the cells were stained with antibodies against CD4+and CD8+T cells expressing IL-17. The addition of tachyzoites to cell cultures induced the synthesis of IL-5, IL-10, and TNF-αby cells from seronegative parturient women and of IL-5 and IL-10 by cells from seropositive, nonpregnant women. We observed a lower level of IL-17-expressing CD4+and CD8+T lymphocytes in cultures of cells from seronegative and seropositive parturient and nonpregnant women that were stimulated with tachyzoites, whereas analysis of the CD4+and CD8+T cell populations showed a higher level of CD4+T cells compared with CD8+T cells. These results suggest that the cytokine pattern and IL-17-expressing CD4+and CD8+T lymphocytes may have important roles in the inflammatory response toT. gondii, thus contributing to the maintenance of pregnancy and control of parasite invasion and replication.