AUTHOR=Li Haoran , Zhang Jing , Su Changwei , Tian Xiaowei , Mei Xuefang , Zhang Zhenchao , Wang Mingyong , Li Xiangrui , Wang Shuai 

TITLE=Dynamic Expressions of TIGIT on Splenic T Cells and TIGIT-Mediated Splenic T Cell Dysfunction of Mice With Chronic Toxoplasma gondii Infection

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.700892

DOI=10.3389/fmicb.2021.700892

ISSN=1664-302X

ABSTRACT=<p>As an immunosuppressive receptor, T-cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT) play a critical part in cellular immune regulation mediated by pathogen infection. Whereas, TIGIT expression on splenic T cells in hosts infected with <italic>Toxoplasma gondii</italic> cysts has not been studied. In this study, we detected TIGIT expression and the changes of immune function in the spleen by flow cytometry and real-time PCR (RT-PCR). We found that TIGIT expression on splenic T cells increased significantly post infection. At the same time, splenic TIGIT<sup>+</sup>T<sub>CM</sub> cells were activated and transformed into TIGIT<sup>+</sup>T<sub>EM</sub> cells during the infection, and the cytotoxicity of TIGIT<sup>+</sup> T cells was reduced in the later stage of infection. This study shows that chronic <italic>T. gondii</italic> infection can upregulate TIGIT expression on the surface of T cells and affect immune cell function.</p>