AUTHOR=Sui Hongshu , Dongye Shengyi , Liu Xiaocui , Xu Xinghua , Wang Li , Jin Christopher Q. , Yao Minhua , Gong Zhaoqing , Jiang Daniel , Zhang Kexin , Liu Yaling , Liu Hui , Jiang Guomin , Su Yanping TITLE=Immunotherapy of targeting MDSCs in tumor microenvironment JOURNAL=Frontiers in Immunology VOLUME=13 YEAR=2022 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2022.990463 DOI=10.3389/fimmu.2022.990463 ISSN=1664-3224 ABSTRACT=

Myeloid-derived suppressor cells (MDSCs) are a group of heterogeneous cells which are abnormally accumulated during the differentiation of myeloid cells. Immunosuppression is the main functional feature of MDSCs, which inhibit T cell activity in the tumor microenvironment (TME) and promote tumoral immune escape. The main principle for immunotherapy is to modulate, restore, and remodel the plasticity and potential of immune system to have an effective anti-tumor response. In the TME, MDSCs are major obstacles to cancer immunotherapy through reducing the anti-tumor efficacy and making tumor cells more resistant to immunotherapy. Therefore, targeting MDSCs treatment becomes the priority of relevant studies and provides new immunotherapeutic strategy for cancer treatment. In this review, we mainly discuss the functions and mechanisms of MDSCs as well as their functional changes in the TME. Further, we review therapeutic effects of immunotherapy against MDSCs and potential breakthroughs regarding immunotherapy targeting MDSCs and immune checkpoint blockade (ICB) immunotherapy.