Abstract: Objective　To construct a cDNA library of Sparganum mansoni and immunoscreen antigen candidates for immunodiagnosis of sparganosis mansoni. Methods　Total RNA was extracted from S. mansoni, and reversely transcribed into cDNA, which was ligated into the phage vector. These recombinant vectors were packaged in vitro to construct the SMART cDNA library of S. mansoni. Then, the cDNA library was immunoscreened with sera from patients with sparganosis mansoni to yield positive clones. The inserted fragments of positive clones were sequenced and subjected to homology analyses, and the structure and functions of the coding proteins were predicted. Results　The SMATR cDNA library of S. mansoni was successfully constructed. The titer of the cDNA library was 6.25 × 106 pfu/mL, with a recombinant efficiency of 100%, and the mean length of the inserted fragments in the library was larger than 1 100 bp. A total of 12 positive clones were obtained by immunoscreening, and were categorized into Sm⁃I (Sm60⁃1), Sm⁃II (Sm58⁃1), Sm⁃III (Sm20⁃1) and Sm⁃IV (Sm22⁃3), with 1 134, 1 063, 883 bp and 969 bp long inserted fragments. Their coding proteins were highly homologous with the Spirometra erinaceieuropaei antigenic polypeptide, cytoplasmic antigen, ribosomal protein S4⁃like protein and unnamed protein product, respectively. Conclusions　A SMART cDNA library of S. mansoni has been successfully constructed and 4 categories of positive clones have been identified, which provides a basis for further studies on diagnostic antigens for sparganosis mansoni.

Key words: Sparganum mansoni, cDNA library, Immunoscreening, Diagnostic antigen, SMART technique

摘要： 目的　构建曼氏裂头蚴cDNA文库，通过免疫筛选获得曼氏裂头蚴病诊断候选抗原基因。方法　提取曼氏裂头蚴虫体总RNA，反转录合成cDNA，连接噬菌体载体，经体外包装后构建曼氏裂头蚴SMART cDNA文库。用曼氏裂头蚴病患者血清免疫筛选cDNA文库，获得阳性克隆，测定阳性克隆插入片段的DNA序列，进行同源性分析并预测编码蛋白的结构和功能。结果　成功构建了曼氏裂头蚴cDNA文库，文库滴度为6.25 × 106 pfu/mL，重组率为100%，文库插入片段的平均长度大于1 100 bp。经免疫筛选获得12个阳性克隆，分为Sm⁃Ⅰ、Sm⁃Ⅱ、Sm⁃Ⅲ和Sm⁃Ⅳ4类，其代表克隆为Sm60⁃1、Sm58⁃1、Sm20⁃1、Sm22⁃3，插入片段长度分别为1 134、1 063、883、969 bp，编码蛋白分别与欧猥迭宫绦虫抗原多肽、胞质抗原、核糖体蛋白S4样蛋白和未命名蛋白具有较高同源性。结论　成功构建了曼氏裂头蚴SMART cDNA文库，获得了4类阳性克隆，为曼氏裂头蚴病诊断抗原的进一步研究奠定了基础。

关键词: 曼氏裂头蚴, cDNA文库, 免疫筛选, 诊断抗原, SMART技术