犬吉氏巴贝斯虫BgTRAP的原核表达及抗原表位分析

Prokaryotic expression of canine Babesia gibsoni BgTRAP and its epitope identification

为表达犬吉氏巴贝斯虫Bg TRAP蛋白及鉴定其抗原表位,本研究将犬吉氏巴贝斯虫Bg TRAP编码基因的密码子进行优化和高效表达,并利用生物学软件分析预测,结果显示,Bg TRAP中存在10个潜在的线性抗原表位,通过原核表达系统对其预测表位的多肽进行表达,以筛选的阳性血清样品为检测抗体进行ELISA检测,结果表明其中3个多肽能够与抗体特异性结合,其多肽序列分别为126DYVIAVEDTTHFGE139、672AYILAGFA GLLLIT685和497SDELGDEMGLTTNE510。本研究对Bg TRAP蛋白抗原表位的鉴定,为进一步开发基于Bg TRAP的犬吉氏巴贝斯虫诊断抗原及Bg TRAP的免疫学特性研究奠定了基础。

In order to express the thrombospondin-related adhesive protein （BgTRAP） of Babesia gibsoni and identify its antigen epitopes, the BgTRAP gene of canine B.gibsoni was code-optimized and efficiently expressed in E.coli. In addition, the results of ELISA coating with the recombinant BgTRAP was highly coincident with the indirect immunofluorescence assay for the clinical serum sample detections. Furthermore, the epitopes of BgTRAP were panned by the ELISA coating with 10 polypeptides expressed in E.coli, respectively, which were predicted to be the epitopes in BgTRAP by the related bio-soffware, of which 3 epitopes were identified to react specifically with the positive sera against B.gibsoni, which included 126DYVIAVEDTTHFGE139, 672AYILAGFAGLLLIT685 and 497SDELGDEMGLTTNE510, respectively. These data provided a basis for further study of the BgTRAP and development of diagnostic method for detecting B.gibsoni infection.