跨膜蛋白受体在LRRC19调节机体先天免疫应答反应中的作用  

LRRC19,as a transmembrane protein receptor,modultes innate immune response

作　　者：柴立民[1] 车永哲[2] 杨荣存[1] 

机构地区：[1]南开大学医学院分子免疫学实验室,天津300071 [2]南开大学医学院解剖学教研室,天津300071

出　　处：《解放军医学杂志》2010年第1期36-39,共4页Medical Journal of Chinese People's Liberation Army

基　　金：国家自然科学基金(30771967,30872315);国家科技部基金(06C26211200695,2008AA02Z129);国家高技术研究发展计划(863计划,2006AA020502);天津市科委基金(07JCZDJC03300,06ZHCXSH04800)

摘　　要：目的确定已初步鉴定的富亮氨酸重复结构(LRR)蛋白家族成员LRRC19在脾细胞中的表达及定位,并对其功能进行初步研究。方法通过生物信息学技术预测LRRC19蛋白结构;mRNA原位杂交和RT-PCR检测LRRC19mRNA在小鼠脾组织以及不同脾细胞中的表达;以不同细菌刺激LRRC19转染的293T细胞,通过分泌性碱性磷酸酶(SEAP)检测技术观察细胞分泌的NF-κB活性的改变。结果LRRC19是一种跨膜蛋白,属于LRR蛋白家族成员,胞外区存在串联排列的4个LRR基序,有单一的跨膜结构域,胞内区有2个酪蛋白激酶2(CK2)磷酸化位点;mRNA原位杂交和RT-PCR结果显示,LRRC19mRNA在脾脏主要表达于B1淋巴细胞;体外实验证实,多种细菌均可使转染LRRC19的细胞NF-κB活性增强。结论LRRC19可能是一种跨膜受体,可识别不同的病原体保守分子,可能参与介导细胞信号转导,激活NF-κB信号途径,启动靶基因转录,调节先天免疫应答过程。Objective To study an identified leucine-rich repeats（LRRs）protein,LRR containing 19（LRRC19）,and to determine the distribution,localization,and biological function of LRRC19 mRNA expression in spleen cells.Methods Bioinformatics analysis was used to predetermine the structure of LRRC19 gene and protein.The distribution and localization of LRRC19 mRNA expression were detected by hybridization in situ with LRRC19 mRNA specific probes and reverse transcriptase polymerase chain reaction（RT-PCR）.Additionally,the activity of secreted alkaline phosphatase（SEAP）was detected for analyzing the nuclear factor-kappa B（NF-κB）activation in HEK293T cells transfected with the expression vector of LRRC19 in vitro.Results LRRC19 was found to be a transmembrane protein,with 4 LRR motifs,a single transmembrane domain and two phosphorylation sites of casein kinase 2（CK2）at cytoplasmic domain,as analyzed through bioinformatics soft wares.Previous study revealed that LRRC19 without cytoplasmic Toll/IL-1 receptor（TIR）domain could activate NF-κB to enhance the expression of proinflammatory cytokines.LRRC 19 could also be demonstrated by ectopic expression in RAW264.7 cells after transfection with murine LRRC19 expression plasmid pcDNA3.1-V5-LRRC19 indicating that it was a transmembrane protein.In persent study,the results of hybridization in situ and RT-PCR showed that LRRC19 mRNA was expressed in the germinal center and splenic cord of mouse spleen.Additionally,LRRC19 was predominantly expressed in CD5＋ lymphocyte,known as B1 cell.In vitro study also indicated that several pathogens might significantly enhance the NF-κB activity of the cells transfected with LRRC19.Conclusion LRRC19 might be a transmembrane receptor,and it may be able to recognize the conserved sequence of pathogens,participate in the induction of cell signaling,activate the NF-κB signal pathway,promote transcription of target genes,and modulate the innate immune response.

关 键 词：LRRC19蛋白 人 B淋巴细胞 NF-ΚB 

分 类 号：R392.11[医药卫生—免疫学]