Qiu, Si, Hong, Ruoxi, Zhuang, Zhenkun, Li, Yuan, Zhu, Linnan, Lin, Xinxin, Zheng, Qiufan, Liu, Shang, Zhang, Kai, Huang, Mengxian, Lee, Kaping, Lu, Qianyi, Xia, Wen, Xu, Fei, Wang, Xi, Tang, Jun, Xiao, Xiangsheng, Wei, Weidong, Yuan, Zhongyu, Shi, Yanxia, Hou, Yong, Zhang, Xiuqing, Wang, Jian, Yang, Huanming, Zhan, Qimin, Li, Bo, and Wang, Shusen
Triple-negative breast cancer (TNBC) represents the most aggressive breast cancer subtype, which recently attracts great interest for immune therapeutic development. In this context, in-depth understanding of TNBC immune landscape is highly demanded. Here we report single-cell RNA sequencing results of 9683 tumor-infiltrated immune cells isolated from 14 treatment naïve TNBC tumors, where 22 immune cell subsets, including T cells, macrophages, B cells, and DCs have been characterized. We identify a new T cell subset, CD8+CXCL8+ naïve T cell, which associates with poor survival. A novel immune cell subset comprised of TCR+ macrophages, is found to be widely distributed in TNBC tumors. Further analyses reveal an up-regulation of molecules associated with TCR signaling and cytotoxicity in these immune cells, indicating TCR signaling activation. Altogether, our study provides a valuable resource to understand the immune ecosystem of TNBC. The novel immune cell subsets reported herein might be functionally important in cancer immunity.SIGNIFICANCEThis work demonstrates a single-cell transcriptome atlas of immune cells in treatment naïve TNBC tumors, revealing novel immune cell subsets. This study provides a valuable resource to understand the immune ecosystem of TNBC, which will be helpful for the immunotherapeutic strategy design of TNBC.