CD40-P227A单核苷酸多态性与B细胞信号系统活化的研究  

Effect of CD40-P227A polymorphism at human B cell signaling pathways

作　　者：张文[1] 张烜[1] 曾小峰[1] 张奉春[1] 

机构地区：[1]中国医学科学院中国协和医科大学北京协和医院风湿免疫科,100730

出　　处：《中华微生物学和免疫学杂志》2009年第9期773-777,共5页Chinese Journal of Microbiology and Immunology

基　　金：国家十一五科技支撑项目（2008BA159B02）;人事部留学人员科技活动项目择优资助（M334600）;教育部博士点新教师基金（C334600）

摘　　要：目的探讨CD40的单核苷酸多态性突变（CD40-P227ASNP）对B细胞核因子κB（NF—κB）和活化蛋白1（AP-1）信号系统和B细胞功能的影响。方法使用人RamosB淋巴瘤细胞株，分别将融合黄色荧光蛋白（CFP）的野生型CD40和突变型CD40-P227A质粒，连同表达荧光素酶的NF—κB或AP-1质粒，或融合绿色荧光蛋白（GFP）的NF—κB质粒共转染至Ramos细胞中。用荧光素测定法和流式细胞仪分析检测NF—κB和AP-1信号系统的活化水平。用免疫印迹和ELISA等方法检测IκBα的降解和NF—κB亚单位的核内转移情况。结果与野生型CD40比较，CD40-P227A可诱导增加NF—κB和AP-1的信号活化，并促进IκBα的降解和NF—κB亚单位的核内转移。转染CD40-P227A质粒的细胞分泌IL-6和TNF-α较转染野生型CD40质粒的细胞明显增多。结论CD40-P227ASNP是一种功能性突变，可诱导NF-κB和AP-1信号系统活化，可能为系统性红斑狼疮的易感因素。Objective To investigate the effects of CD40-P227A SNP at human B cell signaling and function. Methods Human Ramos B cells were transfected with plasmids of CFP fusion wild type CD40 and mutant type CD40-P227A, together with plasmids of luciferase fusion NF-KB and AP-1, as well as plasmids of GFP fusion NF-KB. Activation of NF-KB and AP-1 pathway were detected by luciferase assay and flow cytometry, degradation of IκBα and nuclear translocation of NF-KB subunits were tested by Western blot and transfactor ELISA assay. Results Compared with wild type CD40, CD40-P227A SNP induced more degradation of IκBα, increased nuclear translocation of p65, p50 and c-Rel. As well as higher activity of NF-KB, as shown by increased NF-KB luciferase and GFP-NF-κB expressing B cells. Moreover, CD40- P227A SNP induced more activation of AP-1 pathway than CD40. CD40-P227A enhanced B cells function by inducing more excretion of IL-6 and TNF-α. Conclusion Our data indicate that CD40-P227A is a gain-offunction phenotype which induces activation of NF-κB and AP-1 signaling pathways and may contribute to the pathogenesis of the SLE autoimmune disease.

关 键 词：B细胞 CD40 NF—κB信号系统 AP-1信号系统 

分 类 号：R593.241[医药卫生—内科学]