乳腺癌淋巴结微转移患者克隆性T细胞TCRα链CDR3谱型分析

目的 分析乳腺癌微转移淋巴结T细胞克隆性增生及TCR α链谱型偏移情况，了解抗肿瘤T细胞克隆的分子特征。方法 利用RT-PCR扩增10例乳腺癌微转移淋巴结T细胞32个TCR可变区（AV）亚家族的基因，基因扫描检测T细胞克隆性及TCR AV亚家族取用情况，对单克隆家族行PCR扩增TCR α链全长序列，构建重组质粒后测序，分析互补决定区（CDR3）序列。结果 乳腺癌淋巴结微转移患者T细胞呈单、寡克隆、寡克隆趋势和多克隆增生，不同患者表达1～4个TCR AV亚家族。克隆性T细胞的CDR3氨基酸序列不同，但是病例4和病例8含有相同的CDR3氨基酸基序：AM和DDKII。结论 乳腺癌TCR AV基因表达具有多样性特点，TCR AV家族的取用可能与乳腺癌肿瘤抗原的多样性和不同个体的免疫应答反应有关。相同CDR3氨基酸基序的发现可能对乳腺癌的T细胞介导免疫治疗提供帮助。

Complementarity Determining Region 3 Repertoire of Clonal T Cell Receptor α Chain in Patients with Micrometastasis from Breast Cancer

Objective To analyze the clonality of the T cells and specific repertoire skewing of T cell receptor α (TCRα) chain in patients with micrometastasis from breast cancer, and to understand the molecular characteristics of anti-tumor T cell clones. Methods RT-PCR amplification of 32 subfamilies of the TCR AV CDR3 gene and immune spectratyping analysis were used to investigate the repertoire drift of TCR AV CDR3 and clonality of T cells in 10 patients with micrometastasis from breast cancer. The complete DNA sequence (CDS) of TCR AV subfamilies of monoclonal expansion were amplified by PCR. We constructed recombinant plasmid and sequenced. The sequences of TCRα chain and CDR3 were analyzed. Results TCR AV presented specific repertoire skewing in micrometastasis from 10 cases, and only 1-4 TCR AV subfamilies T cells were identified, respectively. Clonal expanded T cells included monoclonal, oligoclonal, oligoclonal trend and multiclonal patterns. The monoclonal expanded T cells had different CDR3 amino acid sequences, but there were some common amino acid motifs of TCR CDR3: AM and DDKII in case 4 and case 8.Conclusion There are diverse expression of TCR AV gene in patients with micrometastasis from breast cancer. The TCRAV gene usage may be closely related to the diversity of breast tumor antigens and the differential immune responses in individual patients. However common amino acid motifs of CDR3 found in some patients may be helpful for T cell-directed therapy for breast cancer.