志贺毒素B亚单位及其模拟表位的制备和免疫保护效应  

Preparation and protective immune-response of Shiga toxin B subnnit and its predicted epitopes

作　　者：包士中[1] 史晶[1] 蔡昆[1] 侯晓军[1] 高翔[1] 刘昊[1] 荫俊[1] 王慧[1] 

机构地区：[1]军事医学科学院微生物流行病研究所病原微生物生物安全国家重点实验室,北京100071

出　　处：《军事医学科学院院刊》2008年第6期537-540,共4页Bulletin of the Academy of Military Medical Sciences

摘　　要：目的:对重组表达的StxB和预测的模拟表位肽进行免疫保护效应评价。方法:用分子生物学方法构建基因工程菌,IPTG诱导表达重组StxB,经复性后进行离子交换层析纯化。同时采用生物信息学手段对StxB的表位相关参数进行分析,预测StxB可能的抗原表位。以纯化的StxB和合成的模拟表位肽免疫小鼠后攻毒,评价StxB及其模拟表位肽的免疫保护效应。结果:表达并制备了90%以上纯度重组StxB;发现p14和p17多肽易形成转角和无规卷曲的柔性区段,可及性、极性和亲水性较强,是可能的抗原表位。免疫保护试验显示,经重组StxB和合成多肽免疫的小鼠发病延迟,症状减轻,存活率显著提高。结论:重组StxB和预测的模拟表位肽具有良好的免疫保护效果,为亚单位疫苗及其作用机制的研究奠定了基础。Objective：To evaluate the protective immune-response of the recombinant Shiga toxin B subunit （StxB） and its mimic epitope peptides. Methods：The gene engineering bacterium pET22b （ ＋ ）-stxb/BI21 was constructed by molecular biology techniques. The expressed StxB was then renatured and purified by ion exchange chromatography. Its binding activity was demonstrated in vitro by Western blot. Also, parameters of accessibility, flexibility, polarity, hydrophilicity and secondary-structure of StxB were predicted by bioinformation method. Based on the prediction results, mimic epitope peptides of StxB were synthesized. The BALB/c mice were immunized by the StxB and the mimic epitope peptides, followed by challenge with Shiga toxin, in order to evaluate their protective immune-response. Results： The gene engineering bacterium highly expressed the StxB, and the purified StxB showed a good binding activity in vitro. Two mimic epitope peptides of StxB （sites 10 -26 and sites 54 -67） were predicted by multi-parameter analysis. The BALB/c mice immunized with the StxB and the mimic epitope peptides showed a high survival rate after challenge with Shiga toxin. Conclusion： The StxB and mimic epitope peptides could induce special immune response and protect the BALB/c mice from the challenge with Stx. They could be used as candidate protective antigens.

关 键 词：志贺毒素B亚单位 模拟表位 免疫保护效应 

分 类 号：R392[医药卫生—免疫学]