Knight M, Simpson A J, Bickle Q, Hagan P, Moloney A, Wilkins A, Smithers S R
Mol Biochem Parasitol. 1986 Feb;18(2):235-53. doi: 10.1016/0166-6851(86)90041-1.
Protective immunity has been demonstrated in experimental schistosomiasis and is also believed to occur in man. It can be mediated by antibodies from infected animals or animals immunized with attenuated organisms. Recombinant Escherichia coli synthesizing antigenic polypeptides from the three principal species of schistosome that infect man, Schistosoma mansoni, S. japonicum and S. haematobium, have been constructed. Libraries of adult worm cDNA were prepared from each species in the expression vector lambda gt 11 and directly screened with antibodies from animals experimentally immunized with S. mansoni and S. japonicum and from humans infected with S. haematobium. The S. mansoni clones have been analysed in greatest detail. At least four different types of clones were identified. All the detected recombinant polypeptide antigens were recognised by antibodies from chronically infected mice and most were also recognised by antibodies from mice immunized with attenuated cercariae and anti-surface membrane antibodies. Clones synthesizing species-specific antigens for both S. mansoni and S. japonicum were identified by simultaneous screening of both libraries. At least three types of S. haematobium clones were identified by screening with human infection serum, most of which were species-specific. All the antigens were in the form of fusion peptides with E. coli beta-galactosidase and their expression was induced by isopropylthiogalactopyranoside. Since known protective monoclonal antibodies recognise highly glycosylated membrane proteins which cannot be identified in the form of nascent polypeptides, the direct identification of polypeptide antigens defined by their reactivity, as reported here, is an essential step in producing reagents by recombinant DNA technology, suitable for vaccination and diagnosis.
在实验性血吸虫病中已证实存在保护性免疫，人们也认为在人体中会发生这种免疫。它可由感染动物或用减毒生物体免疫的动物产生的抗体介导。已经构建了重组大肠杆菌，其可合成来自感染人类的三种主要血吸虫——曼氏血吸虫、日本血吸虫和埃及血吸虫的抗原多肽。从每个物种的成虫制备了cDNA文库，这些文库被构建于表达载体λgt 11中，并直接用来自经曼氏血吸虫和日本血吸虫实验免疫的动物以及感染埃及血吸虫的人类的抗体进行筛选。对曼氏血吸虫克隆进行了最详细的分析。鉴定出至少四种不同类型的克隆。所有检测到的重组多肽抗原都能被慢性感染小鼠的抗体识别，大多数还能被用减毒尾蚴免疫的小鼠的抗体和抗表面膜抗体识别。通过同时筛选两个文库，鉴定出了合成曼氏血吸虫和日本血吸虫物种特异性抗原的克隆。用人类感染血清筛选鉴定出至少三种类型的埃及血吸虫克隆，其中大多数是物种特异性的。所有抗原均为与大肠杆菌β-半乳糖苷酶的融合肽形式，其表达由异丙基硫代半乳糖苷诱导。由于已知的保护性单克隆抗体识别的是高度糖基化的膜蛋白，而这些蛋白无法以新生多肽的形式被鉴定出来，因此如本文所述，通过其反应性直接鉴定多肽抗原是利用重组DNA技术生产适用于疫苗接种和诊断的试剂的关键步骤。
