CAFs亚群来源的外泌体lncRNATCDAL调控口腔鳞癌CD8T细胞分化及免疫应答机制研究

新近研究表明肿瘤免疫应答与肿瘤浸润淋巴细胞（TILs）异质性密切相关，其中肿瘤抗原特异性CD39+CD103+CD8+TILs能更高效识别杀伤肿瘤，但其分化机制尚不清楚。我们预实验证实该群TILs浸润程度与口腔鳞癌患者预后相关，并对口腔鳞癌原代CAFs行单细胞测序，发现CD90+GPNMB+CAFs亚群与该群TILs表达呈正相关却无空间接触关系，但其释放的外泌体能显著诱导该群TILs分化；对外泌体行RNA测序发现LncRNATCDAL可调控组蛋白修饰及该群TILs分化。后续我们将通过ChIRP和EMSA等一系列实验明确长链非编码RNA调控CD39和CD103组蛋白修饰的具体机制，并通过动物实验和临床样本验证相关标志物的临床意义。本课题以CAFs亚群为切入点，探讨其来源的外泌体长链非编码RNA调控CD8+T细胞分化及免疫应答机制，可望为增强实体瘤免疫应答提供新思路。

Recent studies have shown that tumor immune response is closely related to the heterogeneity of tumor-infiltrating lymphocytes (TILs). Among TILs subsets, tumor-reactive CD39+CD103+CD8+TILs more efficiently identify and kill tumor cells. However, the mechanism of CD39+CD103+CD8+TILs differentiation is unclear. A significant association was confirmed between high infiltration of CD39+CD103+CD8+TILs and favorable prognosis in oral squamous cell carcinoma (OSCC) patients in preliminary experiments. Following single-cell RNA sequencing on primary cancer-associated fibroblasts(CAFs) isolated from tumor tissues in OSCC patients, we found that CD90+GPNMB+CAFs is positively correlated with the infiltration level of CD39+CD103+CD8+TILs, but there was no spatial contact relationship. Moreover, the exosomes derived from the CAFs subset could significantly induce the differentiation of CD39+CD103+CD8+TILs. Following RNA sequencing of exosomes, we revealed that LncTCDAL could regulate histone modification and the differentiation of CD39+CD103+CD8+TILs. Next, we will conduct ChIRP, EMSA and other experiments in the aim to clarify the molecular mechanism driving the histone modification of LncTCDAL on CD39 and CD103, and verify the clinical significance of related biomarkers through animal experiments and clinical samples. Our study in which the CAFs subset was taken as the entry point, explore the functional roles of exosomes-derived long non-coding RNA in regulating CD8+T cell differentiation and anti-tumor immune response. Insight into the underlying mechanisms is expected to lead to new ideas for promoting immunotherapeutic approaches to treat solid tumors.