TLR5-dependent immunogenicity of a recombinant fusion protein containing an immunodominant epitope of malarial circumsporozoite protein and the FliC flagellin of Salmonella Typhimurium
TLR5-dependent immunogenicity of a recombinant fusion protein containing an immunodominant epitope of malarial circumsporozoite protein and the FliC flagellin of Salmonella Typhimurium
复制标题
DOI：
10.1590/s0074-02762011000900021
复制
发表时间：
2011-08-01
期刊：
影响因子：
--
通讯作者：
Rodrigues, Mauricio Martins
中科院分区：
文献类型：
--
作者：
Camacho, Ariane Guglielmi Ariza;Teixeira, Laís Helena;Rodrigues, Mauricio Martins
最近，我们描述了基于融合蛋白的表达的新的疟疾疫苗候选物的改进的免疫原性，所述融合蛋白含有裂殖子的免疫显性表位和作为先天免疫激动剂的肠道沙门氏菌血清型鼠伤寒沙门氏菌鞭毛蛋白（FliC）蛋白。在这里，我们测试了基于来自疟疾子孢子的免疫显性B细胞表位的类似策略是否也可以产生免疫原性融合多肽。构建了含有间日疟原虫环子孢子（CS）蛋白的VK 210变体的C-末端重复区的重组His 6-标记的FliC蛋白。该重组蛋白在大肠杆菌中以可溶性蛋白的形式成功表达，并通过镍-琼脂糖珠亲和层析和离子交换层析进行纯化。间日疟原虫子孢子CS蛋白特异性单克隆抗体（VK 210）能够识别纯化的蛋白质。在不存在任何常规佐剂的情况下用重组融合蛋白皮下免疫的C57 BL/6小鼠产生蛋白特异性全身抗体应答。然而，在TLR 5基因表达缺陷的小鼠中，这种免疫应答非常低。这些结果扩展了我们之前关于这些重组融合蛋白的免疫原性的观察，并提供了证据表明，负责这种免疫激活的主要机制涉及与TLR 5的相互作用，这在之前对于任何重组FliC融合蛋白都没有得到证实。
Recently, we described the improved immunogenicity of new malaria vaccine candidates based on the expression of fusion proteins containing immunodominant epitopes of merozoites and Salmonella enterica serovar Typhimurium flagellin (FliC) protein as an innate immune agonist. Here, we tested whether a similar strategy, based on an immunodominant B-cell epitope from malaria sporozoites, could also generate immunogenic fusion polypeptides. A recombinant His6-tagged FliC protein containing the C-terminal repeat regions of the VK210 variant of Plasmodium vivax circumsporozoite (CS) protein was constructed. This recombinant protein was successfully expressed in Escherichia coli as soluble protein and was purified by affinity to Ni-agarose beads followed by ion exchange chromatography. A monoclonal antibody specific for the CS protein of P. vivax sporozoites (VK210) was able to recognise the purified protein. C57BL/6 mice subcutaneously immunised with the recombinant fusion protein in the absence of any conventional adjuvant developed protein-specific systemic antibody responses. However, in mice genetically deficient in expression of TLR5, this immune response was extremely low. These results extend our previous observations concerning the immunogenicity of these recombinant fusion proteins and provide evidence that the main mechanism responsible for this immune activation involves interactions with TLR5, which has not previously been demonstrated for any recombinant FliC fusion protein.