HePTP抑制BCR诱导的未成熟B淋巴细胞的凋亡  

HePTP Promotes Survival of Immature B Lymphoma Cells from BCR-induced Apoptosis

作　　者：俞冬熠[1] 张全启[1] 齐洁[1] 田茂鑫[1] 

机构地区：[1]中国海洋大学生命科学与技术学部遗传与种质工程研究室

出　　处：《同济大学学报（医学版）》2006年第4期27-31,39,共6页Journal of Tongji University(Medical Science)

摘　　要：目的研究血细胞专有的酪氨酸磷酸酶(hematopoietic protein tyrosine phosphatase,HePTP)在B细胞凋亡研究模型[B细胞表面抗原受体(B-cell antigen receptor,BCR)诱导的WEHI231细胞的凋亡]中的作用及机制。方法HePTP是BCR诱导WEHI231细胞发生凋亡的信号传导通路中ERK和p38激酶的调节因子。应用PCR定点突变的方法,构建起含有功能性突变的HePTP基因的逆转录病毒载体。将野生型与突变型质粒转染BOSC23细胞,收集病毒上清,感染WEHI231细胞后,加入anti-IgM诱导凋亡,流式细胞仪检测被感染细胞的凋亡情况。western印迹检测野生型及突变型HePTP的表达及作用。结果野生型HePTP基因的过量表达抑制WEHI231细胞的凋亡,而失去与底物作用位点及催化域失活的突变型基因的过量表达则均没有抑制凋亡的作用。结论HePTP抑制BCR诱导的未成熟B淋巴细胞的凋亡,与MAPK底物结合,并同时使其磷酸化的水平发生变化,是HePTP发挥抗凋亡作用的两个必要条件。Objective To investigate the involvement and possible mechanisms of hematopoietic protein tyrosine phosphatase （HePTP） in BCR-induced apoptosis in an immature B cell line （WEHI-231）. Methods HePTP, a regulator of Erk and 1938 kinase pathways, consists of two functional domains： a kinase-interacting motif （KIM） and a catalytic domain. To assess the respective roles of the individual domains in regulating B cell apoptosis, mutations were introduced into both domains by PCR-mediated, site-directed mutagenesis. Retroviruses expressing the wild type or mutant HePTP proteins were generated by transfecting plasmid DNA into the retroviral packaging cell line, BOSC 23. They were then used to infect WEHI 231 cells. The infected cultures were verified for mutant protein expression and examined by flow cytometry for changes in apoptotic behaviors of the cells after BCR engagement. Results Wide type HePTP, when ectopically expressed in WEH-I231 cells, provided significant protection from BCR-induced apoptosis. However, overexpression of either the catalytic or KIM domain alone was unable to confer detectable anti-apoptotic effects. Conclusion HePTP overexpression enhances the survival of BCR-engaged WEHI-231 ceils and such pro-survival effects may require coordinated actions of both KIM and the catalytic domains on its physiological substrates. The respective roles of these substrates in mediating the pro-survival activity of HePTP remain to be determined.

关 键 词：B细胞表面原抗体 酷氨酸磷酸酶 B淋巴细胞 细胞凋亡 

分 类 号：R394[医药卫生—医学遗传学]