小鼠CXCR3基因转染细胞株的构建、鉴定及生物学功能研究

Construction of murine CXCR3 gene transfected cell line,identifiction and study of its biological function

目的：构建含有小鼠CXCR3基因的重组逆转录病毒载体，获得稳定表达小鼠CXCR3分子的基因转染细胞株L929-mCXCR3，研究CXCR3与其配IP-10相互作用引起的L929-mCXCR3的迁移效应。方法：取1只雌性BALB／c小鼠（7周龄），尾静脉注射0．5mgConA／只，12h后取其脾脏，研磨成细胞悬液后，分离获得脾脏细胞；用含5万U／L人IL-2的RPMll640培养基培养3d；收集细胞，TRIzol一步法抽提总RNA，RT—PCR扩增小鼠CXCR3全长基因，装入逆转录病毒载体pEGZ—term，与两辅助病毒载体脂质体法共转染包装细胞293T，收集含完整逆转录病毒颗粒的293T培养上清感染L929细胞，重复感染3次，筛选获得含Zeocin抗性的稳定表达小鼠CXCR3分子的基因转染细胞株。采用流式细胞术（FCM）和RT—PCR对CXCR3分子的表达进行鉴定。Transwell分析基因转染细胞株L929-mCXCR3在IP．10作用下的迁移能力。结果：构建了含小鼠CXCR3基因的重组逆转录病毒载体，建立了稳定表达小鼠CXCR3分子的基因转染细胞株L929-mCXCR3，其膜表面CXCR3分子阳性表达率为97．0％；该基因转染细胞株在IP-10的介导下可定向迁移，迁移率为4．356％。结论：L929-mCXCR3细胞株为研究CXCR3信号通路的生物学特性、肿瘤转移模型的建立和抗小鼠CXCR3单克隆抗体的研制奠定了基础。

AIM： To construct recombinant murine CX- CR3 gene retroviral vector and obtain L929-mCXCR3 gene transfected cell line for stably expressing murine CXCR3. We further study on L929-mCXCR3 migration effect resulted from interaction by CXCR3 and its ligand IP-10. METH- ODS： One female BALB/c mouse （7 weeks） was injected with 0. 5 mg Con A intravenously （L v. ） via a tail vein. Twelve hours later the mouse was sacrificed and the spleen was removed. The spleen was preesed through a 150 ~m statinless steel mesh. The isolated splenocytes were cul- tured in RPMl1640 supplemented with 50 U/mL human IL-2 for 3 days. Total RNA was extracted with TRIzol. Murine CXCR3 gene of full length was amplified by RT-PCR, then, it was inserted into retrovirus vector pEGZ-term. The recom- binant vector together with its helper virus vector were co- transfected into package cell 293T with LipofectamineTM 2000. The supernatant of 293T was collected for infecting L929 cells（ repeated three times）, and cell clones stably ex- pressing murine CXCR3 molecule were screened by zeocin （500 mg/L）. We used FCM and RT-PCR to verify expres- sion of CXCR3 from protein level and gene level, respectively. Studied migration ability of L929-mCXCR3 interacted with its ligand IP-10 by transwell system. RESULTS： We have constructed recombinant murine CXCR3 gene retroviral vector and obtained L929-mCXCR3 gene transfected cell line which can stably expressing murine CXCR3 molecule. Positive expression rate of membrane is 97.0%, and it can directly migrate induced by IP-10, the chemotatic index is 4.356%. CONCLUSION： Construction of L929-mCXCR3 cell line has laid a good foundation on research of biologic characteristics of CXCR3 signal path , establishment of tumor metastasis model and preparation of anti-murineCX- CR3 monoclonal antibody.