肺炎链球菌候选蛋白疫苗ClpP的保守性和抗原性

Conservation and antigenicity of Streptococcus pneumoniae vaccine candidate protein ClpP

目的:评价酪蛋白裂解酶P(ClpP)作为候选疫苗的保守性和抗原性,分析在不同血清型肺炎链球菌(SPN)中的表达情况.方法:以TIGR4型SPN的ClpP基因序列设计引物,分别以12株不同血清型SPN的基因组DNA为模板,对ClpP基因进行聚合酶链反应(PCR)扩增、胶回收产物与PMD-18克隆载体连接后进行测序,运用生物信息学方法对其核苷酸及推测的氨基酸序列及抗原性进行分析,并利用West-ernBlot方法检测12株不同血清型SPN的ClpP蛋白的表达情况.结果:12株不同血清型SPN的ClpP基因序列和Gen-Bank数据库对已公布的TIGR4型SPN的ClpP基因一致性>99.0%,推测的氨基酸序列一致性>99.5%.WesternBlot结果显示anti-ClpP多克隆抗体与12型SPN的菌体蛋白能够起交叉反应.结论:ClpP蛋白在不同型SPN之间同源性高,在不同型SPN菌株中均有表达.ClpP是一个具有前景的SPN候选蛋白疫苗因子.

AIM： To evaluate the conservation and antigenicity of Streptococcus （S.） pneumoniae vaccine candidate protein ClpP and analyze its expression in S. pnenmoniae of different serotypes. METHODS： For gene distribution analysis, the fulllength ClpP gene was amplified by PCR with genomic DNA from 12 different strains representing the 12 most important serotypes of S. pneumoniae in China. Gene-specific primers were designed according to the ClpP gene sequence of TIGR4 S. pneumoniae. The obtained PCR products were then cloned into PMD-18 vector and subsequently sequenced, followed by being analyzed through bioinformatics method. Moreover, Western Blot method was employed to demonstrate the expression of ClpP in different S. pneurnoniae serotypes. RESULTS： ClpP was sequenced from 12 tested strains and was found to be highly conserved, with 99.0% gene identity and 99. 5% predicted amino acids sequence identity. The antigen epitopes of ClpP were also found to be completely identical in different serotypes of S. pneumoniae using the antigenic software. In addition, the corresponding ClpP protein was found in all of the 12 tested strains using immunoblot analysis method. CONCLUSION： ClpP is highly conserved among all of the tested strains, thus making ClpP a promising candidate vaccine for single use or using in combination with other potential vaccine protein candidates.