日本血吸虫尾蚴抗原模拟表位的筛选及其免疫保护性

目的 筛选日本血吸虫尾蚴抗原的模拟表位，探讨其对日本血吸虫的免疫保护性。方法 用粗提日本血吸虫尾蚴抗原的抗体IgC作配体筛选噬菌体12肽库，按“吸附－洗脱－扩增”的过程进行三轮筛选；随机挑取单个噬菌体克隆进行Dot-ELISA检测；用混和噬菌体克隆免疫小鼠3次，攻击感染45d后剖杀冲虫，计算虫数及肝卵数。结果 经三轮筛选，特异性噬菌体得到富集，挑取11个噬菌体克隆经Dot-ELISA鉴定，均与日本血吸虫尾蚴抗原免疫血清呈特异性反应。与对照组相比，混和噬体克隆免疫小鼠的减虫率为18.79%，减卵率为38.00%。结论 利用噬菌体随机肽库技术获得了日本血吸虫尾蚴抗原的模拟表位，这些表位能诱导对日本血吸虫的保护性免疫。

Protective immunity against Schistosoma japonicum induced by epitopes mimicking cercariae antigen of Schistosoma japonicum

Objective To immunoscreen mimic epitopes of Schistosoma japonicum(Sj) cercariae antigens and explore their immunoprotection against Sj. Methods Phage random peptide library of 12 amino acids was immunoscreened with purified IgG from mouse sera immunized with Sj cercariae antigens. Positive clones collected after three rounds of biopanning were detected by Dot -ELISA. Mice were immunized with mixed positive phage clones for three times, and all mice were perfused 45 days after challenge with Sj cercariae.The worms and liver eggs were counted. Results The specific phages-binding to IgC were enriched after three rounds of biopanning. Eleven clones detected by Dot - ELISA bound to the specific IgG of sera immunized with Sj cercariae antigens. Sera immunized with mixed positive phage clones reacted with Sj cercariae antigens. Immunoprotection against Sj was induced by immunization of mixed phage positive clones. Conclusion The specific antigenic epitopes mimicking Sj cercariae antigens were obtained by im-munoscieening phage random peptide library and immunoprotection can be induced by these epitopes.