γδT细胞可浸润到多种肿瘤组织中，在机体对肿瘤的免疫监视及抗肿瘤免疫中发挥重要的作用。然而鉴定更多的γδT细胞识别的肿瘤相关抗原，阐明γδT细胞抗原识别模式和效应机制，仍然是该研究领域内的最大挑战。肿瘤患者的TCRγδ CDR3免疫组库特征反映了γδT细胞抗肿瘤免疫的状态，患者优势的CDR3序列能作为特异性的探针，筛选γδT细胞识别的肿瘤相关抗原。本研究拟以三种不同的肿瘤（肺癌、肝癌和乳腺癌）为代表，通过免疫组库技术，分析肿瘤相关γδT细胞CDR3免疫组库特征。并从中挑选肿瘤优势CDR3序列，进行肿瘤结合特异性验证，筛选更多γδT细胞所识别的肿瘤相关抗原，最后用这些配体扩增γδT细胞，分析扩增前后γδT细胞CDR3免疫组库特征的变化。本研究结果将为阐明γδT细胞抗原识别及在抗肿瘤免疫中的作用机制奠定基础，肿瘤特异性的CDR3序列及肿瘤相关配体，能为肿瘤的早期免疫诊断和免疫治疗提供新的途径。

γδ T cells can infiltrate into tumor tissues and play crucial roles in tumor immune surveillance and antitumor immunity. However, it is the biggest challenge to identify more tumor associated ligands recognized by γδ T cells and clarify the antigen recognition patterns and effect mechanisms of γδ T cells. The specificity of TCRγδ CDR3 immune repertoire in tumor patient reflects the antitumor immune response of γδ T cells and the predominant CDR3 sequences can be used as specific probes to screen tumor associated ligands recognized by γδ T cells. In this study, multiplex PCR and high-throughput sequencing will be performed to analyze the specificities of TCRγδ CDR3 immune repertoires in tumor patients with hepatocellular carcinoma, lung cancer or breast cancer. Then we will identify predominant sequences and the ligands recognized by γδT cells through an established method based on the binding specificity of CDR3. Finally, we will analyze the TCRγδ CDR3 immune repertoire of γδT cells amplified by identified ligands. This study will identify tumor specific CDR3 sequences and tumor associated ligands recognized by γδT cells, which lays the foundation for further elucidating the antigen recognition pattern and antitumor mechanism of γδT cells and provide a new way for early immunological diagnosis and tumor immune therapy.