To facilitate personalized TCR-T cell development, He et al. performed scRNA- and TCR-seq, and in vitro neoantigen stimulation to characterize tumor antigen-specific T (Tas) cells. Tas cells were enriched in tumors, positively correlated with TMB, showed neoantigen specificity, and specifically expressed CXCL13. TCR-T cells engineered with Tas cell TCRs inhibited the growth of autologous patient-derived xenograft tumors, and high CXCL13 expression was associated with improved OS and better response to ICB in multiple cancer types. CD200 and ENTPD1 were identified as surface markers for CD4+ and CD8+ Tas cells, respectively, and enabled their isolation.

Contributed by Shishir Pant

ABSTRACT: Personalized immunotherapy targeting tumor-specific antigens (TSAs) could generate efficient and safe antitumor immune response without damaging normal tissues. Although neoantigen vaccines have shown therapeutic effect in clinic trials, precise prediction of neoantigens from tumor mutations is still challenging. The host antitumor immune response selects and activates T cells recognizing tumor antigens. Hence, T cells engineered with T-cell receptors (TCRs) from these naturally occurring tumor antigen-specific T (Tas) cells in a patient will target personal TSAs in his/her tumor. To establish such a personalized TCR-T cell therapy, we comprehensively characterized T cells in tumor and its adjacent tissues by single-cell mRNA sequencing (scRNA-seq), TCR sequencing (TCR-seq) and in vitro neoantigen stimulation. Compared to bystander T cells circulating among tissues, Tas cells were characterized by tumor enrichment, tumor-specific clonal expansion and neoantigen specificity. We found that CXCL13 is a unique marker for both CD4(+) and CD8(+) Tas cells. Importantly, TCR-T cells expressing TCRs from Tas cells showed significant therapeutic effects on autologous patient-derived xenograft (PDX) tumors. Intratumoral Tas cell levels measured by CXCL13 expression precisely predicted the response to immune checkpoint blockade, indicating a critical role of Tas cells in the antitumor immunity. We further identified CD200 and ENTPD1 as surface markers for CD4(+) and CD8(+) Tas cells respectively, which enabled the isolation of Tas cells from tumor by Fluorescence Activating Cell Sorter (FACS) sorting. Overall, our results suggest that TCR-T cells engineered with Tas TCRs are a promising agent for personalized immunotherapy, and intratumoral Tas cell levels determine the response to immunotherapy.

Author Info: (1) State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China. Guangdong Provi

Author Info: (1) State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China. Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China. (2) State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China. Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China. (3) State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China. (4) State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China. (5) State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China. (6) State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China. (7) State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China. (8) Guangdong Laboratory Animals Monitoring Institute, Guangdong Key Laboratory of Laboratory Animals, Guangzhou, China. (9) State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China. (10) State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China. (11) State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China. (12) State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China. (13) State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China. (14) State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China. (15) State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China. (16) Guangzhou FineImmune Biotechnology Co., LTD, Guangzhou, China. (17) Guangzhou FineImmune Biotechnology Co., LTD, Guangzhou, China. (18) Guangzhou FineImmune Biotechnology Co., LTD, Guangzhou, China. (19) State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China. dingpr@sysucc.org.cn. (20) State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China. zhangxsh@sysucc.org.cn. (21) State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China. Zhen-jiang.Liu@outlook.com. (22) Guangdong Laboratory Animals Monitoring Institute, Guangdong Key Laboratory of Laboratory Animals, Guangzhou, China. lwd@gdlami.com. (23) State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China. zuozhx@sysucc.org.cn. (24) State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China. zhouph@sysucc.org.cn.