湖北钉螺髓样分化因子88的鉴定及其在抗血吸虫感染固有免疫中的地位  

Identification of a myeloid differentiation factor 88(MyD88)in Oncomelania hupensis against Schistosoma japonicum infection

作　　者：高倩[1] 李艳伟[1] 黄文铃 赵琴平[1] 董惠芬[1] 

机构地区：[1]武汉大学基础医学院人体寄生虫学教研室,武汉430071

出　　处：《中国血吸虫病防治杂志》2017年第2期174-181,共8页Chinese Journal of Schistosomiasis Control

基　　金：国家自然科学基金(81401685);湖北省卫生和计划生育委员会血防专项(WJ2015XB008)

摘　　要：目的克隆、鉴定湖北钉螺(Oncomelania hupensis)髓样分化因子88(MyD88)基因,并通过观察感染日本血吸虫前后钉螺各组织中MyD88 m RNA表达水平的变化,探讨其在抗血吸虫感染固有免疫中的地位。方法通过c DNA末端快速扩增技术(Rapid amplification of c DNA ends,RACE)获取湖北钉螺MyD88全长c DNA序列,预测其蛋白结构域,并进行多序列比对及保守区域分析,构建系统进化树。使用实时荧光定量PCR(Real-time quantitative PCR,RT-q PCR)技术检测MyD88基因在血吸虫感染前后钉螺各组织中的表达变化。结果湖北钉螺MyD88全长c DNA开放阅读框(Open reading frame,ORF)1 406 bp,编码468个氨基酸,蛋白N端和C端分别存在死亡结构域和TIR(Toll/interlrukin-1 receptor,TIR)结构域。与其他软体类MyD88氨基酸序列比对,相似性为38%~52%;系统进化树提示钉螺MyD88和光滑双脐螺MyD88起源于共同的祖先基因。q PCR结果显示,检测的所有组织中均有MyD88 m RNA的表达,其中血淋巴细胞中表达最为丰富。感染日本血吸虫后,除钉螺头足外,MyD88 m RNA在肝脏、生殖腺、血淋巴细胞等组织中均有上调表达,以血淋巴细胞中上调表达最显著。结论湖北钉螺存在依赖MyD88的TLRs(Toll-like receptors,TLRs)信号通路,MyD88分子可能在钉螺对抗日本血吸虫感染的固有免疫中发挥重要作用。Objective To identify a myeloid differentiation factor 88（MyD88）in Oncomelania hupensis,and characterize the role of MyD88 against Schistosoma japonicum infection. Methods The complete cDNA of MyD88 in O. hupensis was ob-tained by using rapid amplification of cDNA ends（RACE）,and homologues sequences and conserved domains were aligned and the structure of MyD88 was predicted either. A phylogenetic tree of MyD88 was further constructed with other species. In ad-dition,the mRNA expression level of O. hupensis MyD88 before and after S. japonicum infection was investigated by real-time quantitative PCR（RT-qPCR）. Results The cDNA of O. hupensis MyD88 consisted of 1406 bp open reading frame（ORF）,en-coding 468 amino acid residues,which contained death domain and Toll/interlrukin-1 receptor（TIR）domain,the typical fea-tures of MyD88 family proteins. The predicted amino acid sequence of O. hupensis MyD88 shared 38%-52%identity with other mollusc. O. hupensis MyD88 was phylogenetically closeted to Biomphalaria glabrata MyD88. The O. hupensis MyD88 existed in all selected tissues and expressed highly in hemocyte,up-regulated after S. japonicum infection in all selected tissues except cephalopodium,especially higher in whole snail and hemocyte. Conclusion MyD88-dependent signaling pathway is present in O. hupensis and plays an important role in innate immune response against S. japonicum infection.

关 键 词：湖北钉螺 日本血吸虫 固有免疫 TLR信号通路 髓样分化因子88 

分 类 号：R383.24[医药卫生—医学寄生虫学]