%A Zhu,Zhiyuan %A Zhang,Hongbo %A Chen,Baodong %A Liu,Xing %A Zhang,Shizhong %A Zong,Zhitao %A Gao,Mengqi %D 2020 %J Frontiers in Immunology %C %F %G English %K Immune checkpoint inhibitor,PD-1/PD-L1 axis,glioblastoma tumour microenvironment,Immunosuppression,tumour-associated macrophages %Q %R 10.3389/fimmu.2020.588552 %W %L %M %P %7 %8 2020-November-30 %9 Original Research %+ Shizhong Zhang,Department of Functional Neurosurgery, Zhujiang Hospital, Southern Medical University, The National Key Clinical Specialty, The Engineering Technology Research Centre of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration,China,zhangshizhong@smu.edu.cn %+ Zhitao Zong,Department of Neurosurgery, Jiujiang Hospital of Traditional Chinese Medicine,China,zhangshizhong@smu.edu.cn %+ Mengqi Gao,Department of Functional Neurosurgery, Zhujiang Hospital, Southern Medical University, The National Key Clinical Specialty, The Engineering Technology Research Centre of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration,China,zhangshizhong@smu.edu.cn %# %! PD-L1 promotes M2-polarization of macrophages %* %< %T PD-L1-Mediated Immunosuppression in Glioblastoma Is Associated With the Infiltration and M2-Polarization of Tumor-Associated Macrophages %U https://www.frontiersin.org/articles/10.3389/fimmu.2020.588552 %V 11 %0 JOURNAL ARTICLE %@ 1664-3224 %X There has been no significant improvements for immune checkpoint inhibitors since its first use. Tumour-associated macrophages (TAMs) are critical mediators in the PD-1/PD-L1 axis, contributing to the immunosuppressive tumour microenvironment. This study aims to investigate the potential role of PD-L1 in regulating TAMs in glioblastoma. Gene expression data and clinical information of glioma patients were collected from TCGA (n = 614) and CGGA (n = 325) databases. Differentially expressed genes between PD-L1high and PD-L1low groups were identified and subjected to bioinformatical analysis. We found that PD-L1 was frequently expressed in gliomas with a grade-dependent pattern. Higher PD-L1 expression predicted shorter overall survival. Moreover, PD-L1 was positively correlated with immunosuppressive cells (macrophage, neutrophil and immature DC) and negatively correlated with cytocidal immune cells (CD8+ T cell and Th1). Importantly, PD-L1 high expression was significantly correlated with M2-polarization of macrophages (M2-TAMs). We conclude that PD-L1 is an unfavourable prognostic marker for patients with glioblastoma; PD-L1-mediated immunosuppression may attribute to the infiltration and M2-polarization of TAMs.