直肠癌旁移行粘膜中γδT细胞含量及受体基因重排的研究

γδ-T cells and their receptor Vδ gene rearrangement in transitional mucosa of rectal carcinoma

目的 探讨直肠癌旁移行粘膜中γδT细胞含量和受体基因重排表达情况与直肠癌局部复发之间的关系。 方法 运用双色免疫荧光标记流式细胞仪分析法和多聚酶链反应技术 ,检测13例中低位直肠癌患者的癌旁移行粘膜上皮淋巴细胞 (TML)、肿瘤浸润淋巴细胞 (TIL)、正常直肠粘膜上皮淋巴细胞 (IEL)中γδT细胞含量、γδT细胞受体δ链可变区 (γδ TCRVδ)基因重排表达。结果 TML中γδT细胞的含量显著地高于TIL、但显著低于IEL(P <0 0 5 )。γδ TCRVδ1～Vδ6基因重排在TIL、TML、IEL中均有表达 ,其中Vδ6基因重排在TML中的表达低于TIL、高于IEL(P <0 0 5 )。结论 直肠癌旁移行粘膜上皮中γδT细胞的含量减少 ,提示局部肠上皮免疫监视功能下降 ,可能与肿瘤局部复发有关 ;Vδ6基因重排 ,是在肿瘤影响下γδ TCR发生的受体谱偏移 ,反映局部肠上皮的抗肿瘤特性。

Objective To observe γδ T cells and their receptors Vδ gene rearrangement expression in the transitional mucosa of rectal carcinoma, and to investigate their relations with local tumor recurrence. Methods In 13 patients with rectal carcinoma, γδ T cells in transitional mucosa were measured with two color immunofluorescent flow cytometric analysis and polymerase chain reaction technique. Results The volume of γδ T cells in transitional mucosal lymphocytes(TML) were significantly higher than that in tumor infiltrating lymphocytes(TIL), and significantly lower than that in normal intestinal epithelial lymphocytes(IEL)( P <0 05). The γδ T cell receptors δ chain V region(γδ TCR Vδ1 Vδ6) gene rearrangement was all expressed in TIL,TML and IEL; but the Vδ 6 gene expression in both TML and TIL were higher than that in IEL( P <0 05). Conclusions The decreased volume of γδT cells in TML resulted in decreased local immune function and may be responsible for the local tumor recurrence after resection. The high expression of Vδ6 gene rearrangement in both TIL and TML suggests the skewing of γδ TCR receptors and the abtitumor specificity of TIL and TML in local epithelium.