广州管圆线虫成虫cDNA文库抗原基因的筛选

Immunoscreening of the specific antigen genes from the adult worm cDNA library of Angiostrongylus cantonensis

目的从广州管圆线虫成虫cDNA文库中筛选特异性抗原基因。方法用大鼠感染血清做免疫探针,筛选广州管圆线虫成虫cDNA文库,对筛选得到的阳性克隆作交叉反应试验,PCR扩增外源基因插入片段并测序,用在线生物信息学软件进行同源性比对,推导氨基酸序列和蛋白质结构及进行功能分析。结果获得15个阳性克隆,分属三种基因,1个属中间纤维(IF)家族基因,3个与旋盘尾丝虫和秀丽杆线虫的真皮抗原同源,11个属主要精原蛋白(MSP)家族基因。其中1种基因表达产物没有发生明显交叉反应。结论从广州管圆线虫成虫cDNA文库中初步筛选出1个潜在特异性抗原基因和1个可能的主要抗原基因。

To obtain the specific antigen genes for the purpose of diagnosis, the cDNA of the adult worms of Angiostrongylus cantonensis was screened by using antisera of mice infected with A.cantonensis as immuno probe, and the positive clones obtained were cross reacted with antisera raised by other parasites.Some of inserts of positive clones were specifically amplified by PCR and sequenced. The nucleotides and the deduced amino acid sequences were analyzed by bioinformatics. Experimental results showed that 11 positive clones were obtained through 3 rounds of immunoscreening, in which one was intermediate filament (IF) family gene, there were homologous with the immunodominant hypodermal antigens of Onchocerca volvulus and Caenorhabditis elegan and 11 had high scores to main sperm protein (MSP) family genes. One of them showed negative cross reaction. Of the positive clones obtained, one might be the gene encoding the potential specific antigen of A.cantonensis, and the one possible main antigen gene encoding MSP.