title: Inflammation promotes oral squamous carcinoma immune evasion via induced programmed death ligand-1 surface expression.
abstract: The association between inflammation and cancer provides a new target for tumor biotherapy. The inflammatory cells and molecules within the tumor microenvironment have decisive dual roles in antitumor immunity and immune evasion. In the present study, phytohemagglutinin (PHA) was used to stimulate peripheral blood mononuclear cells (PBMCs) to simulate the tumor inflammatory microenvironment. The effect of immune cells and inflammatory cytokines on the surface expression of programmed cell death-1 ligand 1 (PD-L1) and tumor immune evasion was investigated using flow cytometry (FCM) and anin vivoxenotransplantation model. Based on the data, PHA-activated, but not resting, immune cells were able to promote the surface expression of PD-L1 in Tca8113 oral squamous carcinoma cells via the secretion of inflammatory cytokines, but not by cell-cell contact. The majority of the inflammatory cytokines had no significant effect on the proliferation, cell cycle progression and apoptosis of the Tca8113 cells, although they each induced the expression of PD-L1 in a dose-dependent manner. In total, 99% of the Tca8113 cells expressed PD-L1 following treatment with the supernatant of PHA-stimulated PBMCs. The PHA-supernatant pretreated Tca8113 cells unusually induced Tca8113 antigen-specific CD8+T cell apoptosisin vitroand the evasion of antigen-specific T cell attraction in a nude mouse tumor-bearing model. These results indicate a new mechanism for the promotion of tumor immune evasion by the tumor inflammatory microenvironment.
authors.affiliation: State Key Laboratory of Oral Diseases, West China College of Stomatology, Sichuan University, Chengdu, Sichuan 610041, P.R. China.
authors.forename: Wanlu
authors.initials: W
authors.lastname: Lu
authors.forename: Libing
authors.initials: L
authors.lastname: Lu
authors.forename: Yun
authors.initials: Y
authors.lastname: Feng
authors.forename: Jiao
authors.initials: J
authors.lastname: Chen
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Xiangli
authors.initials: X
authors.lastname: Kong
authors.forename: Sixiu
authors.initials: S
authors.lastname: Chen
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Li
authors.forename: Qianming
authors.initials: Q
authors.lastname: Chen
authors.forename: Ping
authors.initials: P
authors.lastname: Zhang
keywords: PD-L1; inflammation; inflammatory cytokines; oral squamous carcinoma; tumor immune evasion