大鼠抗感染血清筛选日本血吸虫成虫cDNA文库

目的　探讨大鼠抗日本血吸虫 (Schistosomajaponicum ,Sj)感染的分子机制 ,为血吸虫病疫苗的研制提供新的抗原分子。方法　用Sj感染大鼠血清筛选Sj成虫cDNA文库 ,对阳性克隆cDNA插入片段进行PCR扩增及测序分析。 结果　对cDNA文库中约 3× 10 5个噬菌斑进行筛选 ,获 7个阳性克隆 ,其插入基因片段大小为 0 9kb～ 2 0kb。初步测序获 5个部分序列 ,其中R3与Sj线粒体基因明显同源 ;R5为新基因序列 ,命名为Sj-Cs2 (GenBank的登录号为AY0 36 5 80 ) ,经计算机分析该基因片段编码 2 0 6个氨基酸组成的跨膜蛋白 ,Sj-Cs2蛋白含有 3个蛋白激酶C磷酸化位点和 6个N -肉豆蔻酸化位点 ;其余序列亦为新基因片段 ,但无完整编码框。结论　筛选获得了与大鼠抗Sj感染有关的基因克隆 ,相关克隆cDNA全长的获取、新基因的结构与功能以及免疫学特性值得深入研究

Immunoscreening of Schistosoma japonicum adult worm cDNA library with sera of infected rats

Aim To explore the molecular mechanism of natural resistance in rat to infection with Schistosoma japoniucm(Sj),and to provide several useful candidate antigens for developing anti schistosomiasis vaccine Methods Sj adult cDNA library was screened with sera of infected rat,and the inserts of positive clones were specifically amplified by PCR and sequenced Results Seven positive clones were obtained from 3×10 5 phage clones after three rounds of screening The size of these inserts ranged from 0 9kb to 2 0kb Five partial sequences were obtained after preliminary sequencing,one had significant homology with Sj mitochondrial gene,while the others were identified as partial sequences of novel genes Among them,Sj-Cs2(GenBank accession number:AY036580) encodes a transmembrane protein with 206 amino acid,which predicted contains three protein kinase C phosphorylation sites and six N myristoylation sites Conclusion The positive clones may be the genes that relate to natural resistance of rat to schistosome infection The full sequences of the novel genes and their molecular and immunological characteristics are valuable to do further investigation