Ovarian carcinoma-infiltrating regulatory T cells were more potent suppressors of CD8 super(+) T cell inflammation than their peripheral counterparts, a function dependent on TIM3 expression

• Published in: Tumor biology Vol. 37; no. 3; pp. 3949 - 3956
• Main Authors: Bu, Meimei, Shen, Yizhen, Seeger, William L, An, Shizhi, Qi, Rongqin, Sanderson, Joanna A, Cai, Yan
• Format: Journal Article
• Language: English
• Published: 01-03-2016
• ISSN: 1010-4283; 1423-0380
• DOI: 10.1007/s13277-015-4237-x

Ovarian carcinoma is one of the most severe cancers in women, with a high relapse rate and limited secondary treatment options. To assist research in novel treatment technologies, including CD8 super(+) T cell-base immunotherapy, we examined the effect of tumor-infiltrating regulatory T cells (Tregs) in inhibiting CD8 super(+) T cell inflammation. We found that compared to their peripheral blood counterparts, tumor-infiltrating Tregs exhibited more potent inhibitory function, which was associated with higher interleukin 10 (IL-10) production in tumor-infiltrating Tregs. Blockade of T cell immunoglobulin mucin 3 (TIM3), a regulatory molecule overrepresented on tumor-infiltrating Tregs, had significantly reverted Treg-mediated suppression. Moreover, expression of TIM3 on tumor-infiltrating Tregs was directly correlated with tumor size. Together, our results demonstrated that ovarian tumor-infiltrating Treg cells were more immunosuppressive than their peripheral blood counterparts in a TIM3-dependent fashion.