AUTHOR=Zhang Yiwei , Jiang Ning , Zhang Ting , Wang Dawei , Feng Ying , Sang Xiaoyu , Yang Na , Chen Qijun 

TITLE=Toxoplasma gondii Genotype Determines Tim-3 Expression Levels in Splenic and Circulatory T Cells in Mice

JOURNAL=Frontiers in Microbiology

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2018.02967

DOI=10.3389/fmicb.2018.02967

ISSN=1664-302X

ABSTRACT=<p><italic>Toxoplasma gondii</italic> is an obligatory intracellular parasite that causes a common infection in many warm-blooded animals. During infection, the host’s immune system plays an important role in confining the dissemination of the parasites in the hosts. T cell immunoglobulin- and mucin domain–containing molecule 3 (Tim-3) has been characterized as an important regulator in cell-mediated immune responses in various infections. Here, we compared Tim-3 expression on splenic and circulatory T, B cells and a few cytokines in the sera of mice infected with the more virulent type I (RH) vs. the low virulent type II (ME49) strain. Tim-3 expression on the splenic and circulatory T cells of mice infected with <italic>T. gondii</italic> (RH strain) was higher than that in mice infected with <italic>T. gondii</italic> (ME49 strain). <italic>T. gondii</italic> infection reduced the proportion of splenic helper T cells (Th) and cytotoxic T cells (Tc) and increased Tim-3 expression. Further, serum levels of interleukin (IL)-2, interferon γ, tumor necrosis factor (TNF)-α, IL-12p70, IL-22, IL-17A, and IL-5 increased significantly after infection. Mice infected with <italic>T. gondii</italic> (ME49 strain) showed higher levels of TNF-α, IL-17A, IL-12p70, and IL-22 than that infected by the RH strain. Our study revealed that <italic>T. gondii</italic> strains may have their inherent ability in triggering different host immune responses, which may explain the clinical variation in diseases severity after infection.</p>