结直肠癌T细胞克隆TCRβ基因CDR3区氨基酸序列的初步分析

Sequence Analysis of the TCRβ CDR3 Region of T Cell Clones in Colorectal Cancer

目的 通过建立结直肠癌肿瘤浸润性淋巴细胞 (tumorinfiltratinglymphocytes ,TIL)和术前外周血 (peripheralbloodlymphocytes ,PBL)中抗肿瘤T细胞克隆的TCRβ基因谱型 ,确定抗肿瘤T细胞克隆的分子特征。方法 采用RT PCR方法扩增结直肠癌TIL和PBL的TCRβ基因的 2 4个不同V家族基因片段 ,经过测序凝胶分离和特殊银染色 ,结合测序结果确定TCRβ基因谱型。 结果 结直肠癌患者具有TIL和 /或PBL中T淋巴细胞的克隆性增殖。有些T细胞克隆表达相同的CDR3区氨基酸基序。CDR3区不同位点具有特征性的疏水性和极性氨基酸以及甘氨酸的分布。结论 通过分析结直肠癌抗肿瘤T细胞克隆特征性的CDR3区氨基酸序列 ,将有益于发现新的抗肿瘤免疫治疗方法。

Objective To study the molecular characteristics of anti-tumor T cell clones by analyzing the sequence of TCRβ CDR3 region from tumor-infiltrating lymphocytes (TIL) and peripheral blood lymphocytes (PBL) of patients with colorectal cancer.Methods The 24 TCR(V gene from TIL and PBL in pre-operation and post-operation were amplified by the method of combined reverse transcriptase-polymerase chain reaction (RT-PCR) with denaturation polyacrylamide sequencing gel eletrophoresis and gene sequencing,Which is called TCRβ gene repertoire.Results There were clonal expression of T lymphocytes both in TIL and PBL from colorectal cancer patients,some of which expressed the same amino acid sequence motif in the CDR3 region. The hydrophobic or polar residues and glycin had special distribution in CDR3 region.Conclusion The anti-tumor T cell clones from patients with colorectal cancer had the common features in TCRβ CDR3 region,which will be helpful for us to develop new methods of immunotherapy to tumors.