体外扩增γδT细胞的肿瘤组织趋向性

Migration of in vitro expanded γδ T cells toward tumor tissue

目的探查体外扩增的γδT细胞向结直肠癌细胞迁移的能力。方法采用密度梯度离心法分离外周血单个核细胞(PBMCs),并利用固相化抗T细胞受体(TCR)γδ抗体进行2周的体外扩增。对扩增的γδT细胞进行免疫荧光染色和流式细胞仪分析或流式细胞仪分选。采用Bioplex 200流体芯片系统分析细胞因子和趋化因子的表达。采用transwell小室进行趋化实验。结果体外扩增的γδT细胞主要表达CCR5和CXCR3 2种趋化因子受体。4种结直肠癌细胞系和10种结直肠癌肿瘤组织中存在CCR5和CXCR3配体的表达。体外扩增的γδT细胞在TCR激活的情况下可以大量产生Th1和Th2型细胞因子,进一步募集γδT细胞。特别是其产生的干扰素γ(IFN-γ)能够提高结直肠癌细胞CXCR3配体的表达量,从而进一步促进γδT细胞的趋近。结论本研究结果为γδT细胞过继免疫治疗结直肠癌提供了重要指征。

Objective To investigate the migration tendency of the expanded γδ T cells toward colorectal cancer cells.Methods Peripheral blood mononuclear cells（PBMCs） were isolated by density gradient centrifugation and stimulated by immobilized T cell receptor（TCR） specific antibody in vitro for two weeks.The expanded cells underwent immunofluorescence staining and flowcytometry analysis or flow sorting.The cytokines and chemokines expressed by T cell were assayed using the Bioplex 200 Suspension Array System.The chemotaxis assays were performed in the transwell chambers.Results Those in vitro-expanded γδ T cells primarily expressed chemokine receptors CCR5 and CXCR3.CCR5 and CXCR3 ligands were detected in four different colorectal cancer cell lines and in ten cases of colorectal cancer.Upon TCR engagement,expanded γδ T cells produced large amounts of Th1 and Th2 cytokines,which further increased γδ T cell accumulation.It is noteworthy that the interferon γ（IFN-γ） produced by the γδ T cells markedly increased the expression of CXCR3 ligands in colorectal cancer cells,which further boosted the migration of the expanded γδ T cells.Conclusions Our data may provide important support to the use of adoptive γδ T cell-based immunotherapy for the treatment of colorectal cancer.