Role of the tumor microenvironment in PD-L1/PD-1-mediated tumor immune escape.

Authors：Jiang, Xianjie; Wang, Jie; Deng, Xiangying; Xiong, Fang; Ge, Junshang; Xiang, Bo; Wu, Xu; Ma, Jian; Zhou, Ming; Li, Xiaoling; Li, Yong; Li, Guiyuan; Xiong, Wei; Guo, Can^*; Zeng, Zhaoyang^*

Source：Molecular Cancer, 2019, 18(1): 10.

DOI：10.1186/s12943-018-0928-4

• Inflammatory factor
• PD-1
• PD-L1
• Tumor immune escape
• Tumor microenvironment

Tumor immune escape is an important strategy of tumor survival. There are many mechanisms of tumor immune escape, including immunosuppression, which has become a research hotspot in recent years. The programmed death ligand-1/programmed death-1 (PD-L1/PD-1) signaling pathway is an important component of tumor immunosuppression, which can inhibit the activation of T lymphocytes and enhance the immune tolerance of tumor cells, thereby achieving tumor immune escape. Therefore, targeting the PD-L1/PD-1 pathway is an attractive strategy for cancer treatment; however, the therapeutic effectiveness of PD-L1/PD-1 remains poor. This situation requires gaining a deeper understanding of the complex and varied molecular mechanisms and factors driving the expression and activation of the PD-L1/PD-1 signaling pathway. In this review, we summarize the regulation mechanisms of the PD-L1/PD-1 signaling pathway in the tumor microenvironment and their roles in mediating tumor escape. Overall, the evidence accumulated to date suggests that induction of PD-L1 by inflammatory factors in the tumor microenvironment may be one of the most important factors affecting the therapeutic efficiency of PD-L1/PD-1 blocking.

• Institution
  湖南省肿瘤医院; University of North Dakota