两个日本血吸虫成虫新基因的克隆和分析

Cloning and analysis of two novd genes of adnh Schisrosoma japonicum .

目的 克隆并分析日本血吸虫(Sj)新的抗原基因,为血吸虫病疫苗研制提供有效的候选抗原分子。方法 用日本吸虫肝门型童虫表膜抗原(SjHmAg)免疫兔血清筛选日本血吸虫成虫cDNA文库,并对阳性克隆的插入片段进行PCR扩增及测序,通过互联网对测序获得的核苷酸序列进行同源性比较分析,并预测蛋白质结构与功能。结果 经3轮筛选,获10个阳性克隆,其插入的Sj成虫cDNA片段大小自0.6～3.0kb不等。对其中3个阳性克隆测序的结果显示,两个为新基因片段,SjHm1、SjHm2的Genbank登录号分别为AY118085,AY124772,分别编码79、66个氨基酸。SjHml蛋白为跨膜蛋白,含1个跨膜区,1个N-肉豆蔻酰化位点。SjHm2蛋白为一个非跨膜蛋白,含1个酪蛋白激酶Ⅱ磷酸化位点。 结论 获得的阳性克隆插入基因片段可能为编码具有保护性作用的日本血吸虫抗原的基因片段。

Objective To clone and analyze novel antigen molecules of Schismsoma japonicum(Sj) and provide effctive vaccine candidate antigens. Methods Schistosoma japordaan adult worm cDNA library was screened with sera of rabbits vaccined with SjHmAg and the inserts of positive clones were specifically amplified by PCR.The positive clones were sequenced and the sequence data were analyzed using Nucleotide BLAST software of NCBI and Expert Protein Analysis System of Swss Institute of Bioinformatics. Result Ten positive clones were obtained after three rounds of immunoscieening.The size of these inserts ranged from 0.6kb to 2. 5kb. Among two novel genes,SjHm1,SjHm2(GenBank accession number: AY 118085 and AY124772) encode proteins with 79 and 66 amino acids. SjHml protein is a transmembrane protein and contains one tranmembrane helix, one N - myristoylation Site. SjHm2 protein contains one casein kinase Ⅱ phosphorylation site. Conclusion The positive clones may be the genes encoding the antigens that can elicit protective immunity against Sj.