AUTHOR=Hao Yaxing , Wang Yifei , Liu Xiaobing , Yang Xia , Wang Pengcheng , Tian Qin , Bai Qiang , Chen Xiangyu , Li Zhirong , Wu Jialin , Xie Zhunyi , Zhou Xinyuan , Zhou Yuyang , Yin Zhinan , Wu Yuzhang , Ye Lilin 

TITLE=The Kinase Complex mTOR Complex 2 Promotes the Follicular Migration and Functional Maturation of Differentiated Follicular Helper CD4+ T Cells During Viral Infection

JOURNAL=Frontiers in Immunology

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2018.01127

DOI=10.3389/fimmu.2018.01127

ISSN=1664-3224

ABSTRACT=<p>Follicular helper CD4<sup>+</sup> T (T<sub>FH</sub>) cells are critical for optimal B-cell-mediated humoral immunity by initiating, fueling, and sustaining germinal center reactions. The differentiation of T<sub>FH</sub> cells relies on multiple intrinsic and extrinsic factors; however, the details by which these factors are integrated to coordinate T<sub>FH</sub> differentiation are largely unknown. In this study, using a mouse model of acute lymphocytic choriomeningitis virus (LCMV) viral infection, we demonstrate that mTOR complex 2 (mTORC2) kinase integrates TCR signaling and ICOS-mediated co-stimulation to promote late differentiation and functional maturation of virus-specific T<sub>FH</sub> cells. Specifically, mTORC2 functions to maintain T<sub>FH</sub> lineage specifications, including phenotypes, migratory characteristics, and functional properties. Thus, our results highlight the importance of mTORC2 in guarding T<sub>FH</sub> phenotypic and functional maturation.</p>