转染人BTLA基因细胞株的建立及其生物学功能的初步研究

目的:构建B、T淋巴细胞衰减子(BTLA)基因转染的细胞作为免疫原,并探讨该基因转染细胞在体外的生物学功能。方法:通过RT-PCR法从经PHA活化的人外周血T细胞中克隆出人BTLA编码区全长基因,经EcoR I和BamHI双酶切后插入逆转录病毒载体pEGZ-Term中构建成重组载体pEGZ-Term/BTLA。用脂质体法以重组逆转录病毒载体转染293T细胞,并用Zeocin抗生素进行长期筛选;流式细胞术分析BTLA在基因转染细胞膜上的表达;通过MTT法和流式细胞术探讨基因转染细胞在体外对T淋巴细胞增殖与活化的影响。结果:流式细胞术检测表明BTLA基因转染的293T细胞膜上能稳定地高表达人BTLA蛋白。BTLA基因转染的293T细胞和T细胞体外共培养显示,与未转染的293T细胞相比,该基因转染的细胞能部分地抑制抗人CD3单克隆抗体(mAb)刺激的T细胞增殖;流式细胞术和ELISA法分析揭示,该基因转染的细胞能够下调T细胞表面活化标志CD25的表达并降低IFN-γ和IL-10的分泌。结论:获得稳定高表达人BTLA基因转染的细胞株。该细胞株在体外对抗人CD3 mAb刺激的T细胞的增殖与活化具有部分地抑制作用。

Establishment of cell line transfected with human BTLA gene and preliminary study on its biological function

AIM: To establish 293T cells expressing human BTLA gene, a novel attenuator for B and T lymphocyte. METHODS: The gene encoding human BTLA was amplified by RT-PCR from PHA activated T cells, and then the target gene fragment was inserted into retrovirus vector pEGZ-Term after being digested with EcoR I and BamH I. The recombinant vector was transfected into 293T cells with LipfectAMINE 2000, and the cells was further selected with Zeocin. Effect of 293T/BTLA cells on T cells proliferation and activation in vitro was been studied by methods of MTT and cytometry. RESULTS: The stable expression of human BTLA on the transfected cell line was identified by flow cytometry analysis. In vitro, 293T/BTLA cells had an inhibitory effect on the proliferation of T cells stimulated by anti-CD3 mAb and down-regulated the expression of activation marker CD25 on the surface of T cells and decreased the secretion of IFN-gamma and IL-10. CONCLUSION: A cell line 293T/BTLA stably expressing the human BTLA protein has been obtained and it can partially inhibit the proliferation and activation of T cells in vitro.