中国寄生虫学与寄生虫病杂志 ›› 2011, Vol. 29 ›› Issue (3): 2-167-171.

• 论著 • 上一篇    下一篇

细粒棘球蚴抗原EPC1基因的克隆、表达及其免疫诊断的研究

 蔡辉霞, 沈玉娟, 韩秀敏, 袁忠英, 王虎, 徐馀信, 胡媛, 卢潍媛, 官亚宜, 曹建平   

  1. 1中国疾病预防控制中心寄生虫病预防控制所,卫生部寄生虫病原与媒介生物学重点实验室,世界卫生组织疟疾、血吸虫病和丝虫病合作中心,上海 200025;2 青海省地方病预防控制所,西宁 811602
  • 出版日期:2011-06-30 发布日期:2012-09-27

Cloning, Expression and Immunodiagnostic Evaluation of Antigen EPC1 from Echinococcus granulosus

CAI  Hui-Xia, SHEN  Yu-Juan, HAN  Xiu-Min, YUAN  Zhong-Ying, WANG  Hu, XU  Yu-Xin, HU  Yuan, LU  Wei-Yuan, GUAN  Ya-Yi, CAO  Jian-Ping   

  1. 1 National Institute of Parasitic Diseases,Chinese Center for Disease Control and Prevention;Key Laboratory of Parasite and Vector Biology,MOH;WHO Collaborating Center of Malaria,Schistosomiasis and Filariasis,Shanghai 200025,China;2 Qinghai Institute for Endemic Disease Prevention and Control,Xining 811602,China
  • Online:2011-06-30 Published:2012-09-27

摘要: 目的  克隆、表达细粒棘球蚴EPC1(EgEPC1)基因,鉴定重组抗原的反应原性,并用棘球蚴病患者血清评价其诊断价值。 方法  从绵羊肝脏棘球蚴囊中分离原头节,提取其总RNA,采用RT-PCR扩增EgEPC1基因,将其克隆至pGEM-T载体,再将其与原核表达载体PET28a(+)连接构建重组质粒PET28a-EgEPC1,转化大肠埃希菌(E. coli)BL21(DE3),经异丙基-β-D-硫代半乳糖苷(IPTG)诱导表达重组蛋白,用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)和蛋白质印迹(Western blotting)对纯化的重组抗原进行鉴定分析。以该重组蛋白作为包被抗原建立ELISA方法,检测细粒棘球蚴病患者血清(60份)特异性IgG抗体, 同时以多房棘球蚴病(37份)、 囊尾蚴病(16份)、 华支睾吸虫病(7份)、 日本血吸虫病(4份)患者和健康人血清(33份)作为对照,评价重组抗原EgEPC1的免疫诊断效果。 结果  双酶切鉴定和测序结果均显示重组质粒PET28a-EgEPC1构建成功。SDS-PAGE和Western blotting分析显示,重组质粒PET28a-EgEPC1在E. coli BL21(DE3)中获得高效表达,产物以可溶蛋白形式存在,重组蛋白EgEPC1的相对分子质量(Mr)约为11 000,可被细粒棘球蚴病患者混合血清识别。EgEPC1对细粒棘球蚴病患者血清的诊断敏感性和特异性分别为78.3%(47/60)和98.3%(59/60),与多房棘球蚴病患者血清交叉反应阳性率为40.5%(15/37)。 结论  EgEPC1重组抗原对细粒棘球蚴病具有较好的诊断价值。

关键词: 细粒棘球绦虫, EPC1基因, 基因表达, 免疫诊断

Abstract: Objective   To clone and express EPC1 gene of Echinococcus granulosus, and investigate its immunogenicity and diagnostic value.   Methods   Total RNA was extracted from hydatid cyst protoscoleces and EPC1 gene of Echinococcus granulosus was amplified by RT-PCR. The PCR product was cloned into pGEM-T vector, and then subcloned into the prokaryotic expression vector PET28a(+). The positive recombinants were transformed into Escherichia coli BL21(DE3), and followed by expression of the protein induced by IPTG. The recombinant protein was identified by SDS-PAGE and Western blotting, and used to establish ELISA. Serum samples from patients with cystic echinococcosis (60 cases), alveolar echinococcosis (37 cases), cysticercosis (16 cases), clonorchiasis sinensis (7 cases), schistosomiasis japonica (4 cases) and healthy persons (33 cases) were examined.   Results   The recombinant plasmid PET28a-EgEPC1 was identified by restriction enzyme digestion and sequencing. SDS-PAGE result showed that the recombinant containing recombinant plasmid PET28a-EgEPC1 expressed a soluble fusion protein of EgEPC1(about Mr 11 000). The protein was recognized by pool sera of cystic echinococcosis patients. The overall sensitivity and specificity of diagnosis by ELISA for cystic echinococcosis were 78.3%(47/60) , and 98.3%(59/60), respectively. The cross reaction with sera of alveolar echinococcosis was 40.5% (15/37).   Conclusion   The recombinant EgEPC1 antigen has diagnostic value in cystic echinococcosis.

Key words: Echinococcus granulosus, EPC1 gene, Gene expression, Immunodiagnosis