KLRG1 restricts memory T cell antitumor immunity

// Lei Li 1 , Shanshan Wan 2 , Kaixiong Tao 1 , Guobin Wang 1 , Ende Zhao 1 1 Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China 2 Department of Surgery, University of Michigan, Ann Arbor, Michigan, USA Correspondence to: Guobin Wang, email: 905083818@qq.com Ende Zhao, email: endezhao@hotmail.com Keywords: KLRG1, senescence, memory T cells, antitumor immunity Received: April 14, 2016 Accepted: August 13, 2016 Published: August 20, 2016 ABSTRACT Killer cell lectin-like receptor subfamily G member 1 (KLRG1) has been found on human memory T lymphocytes. However, the roles of KLRG1 on human T cells especially in tumor microenvironment have not been fully understood. Our results showed KLRG1 expression on T cells significantly increased in tumor microenvironment. KLRG1 + T cells exhibited poor proliferative capacity with decreased effector cytokine production. Meanwhile, KLRG1 + T cells expressed abundant pro-inflammatory cytokines and demonstrated high level of Foxp3 expression. KLRG1 + T cells showed decreased expression of miRNA-101 and higher expression of CtBP2. Our results indicated KLRG1 might contribute to the impaired antitumor immunity of memory T cells in tumor microenvironment. Thus, repressing KLRG1 on human memory T cells might be a novel therapeutics against cancer.