Laboratório de Imunoparasitologia, Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro 21040-900, RJ, Brazil.
Laboratório de Pesquisa em Malária, Instituto Oswaldo Cruz (IOC), Fundação Oswaldo Cruz (Fiocruz), Rio de Janeiro 21040-900, RJ, Brazil.
Int J Mol Sci. 2023 Jul 18;24(14):11571. doi: 10.3390/ijms241411571.
The PvCelTOS, PvCyRPA, and Pvs25 proteins play important roles during the three stages of the lifecycle. In this study, we designed and expressed a recombinant modular chimeric protein (PvRMC-1) composed of the main antigenic regions of these vaccine candidates. After structure modelling by prediction, the chimeric protein was expressed, and the antigenicity was assessed by IgM and IgG (total and subclass) ELISA in 301 naturally exposed individuals from the Brazilian Amazon. The recombinant protein was recognized by IgG (54%) and IgM (40%) antibodies in the studied individuals, confirming the natural immunogenicity of the epitopes that composed PvRMC-1 as its maintenance in the chimeric structure. Among responders, a predominant cytophilic response mediated by IgG1 (70%) and IgG3 (69%) was observed. IgM levels were inversely correlated with age and time of residence in endemic areas ( < 0.01). By contrast, the IgG and IgM reactivity indexes were positively correlated with each other, and both were inversely correlated with the time of the last malaria episode. Conclusions: The study demonstrates that PvRMC-1 was successfully expressed and targeted by natural antibodies, providing important insights into the construction of a multistage chimeric recombinant protein and the use of naturally acquired antibodies to validate the construction.
PvCelTOS、PvCyRPA 和 Pvs25 蛋白在生命周期的三个阶段中发挥重要作用。在这项研究中，我们设计并表达了一种由这些候选疫苗的主要抗原区域组成的重组模块化嵌合蛋白（PvRMC-1）。通过预测进行结构建模后，表达了嵌合蛋白，并通过 301 名来自巴西亚马逊的自然暴露个体的 IgM 和 IgG（总和亚类）ELISA 评估其抗原性。重组蛋白被研究个体的 IgG（54%）和 IgM（40%）抗体识别，证实了组成 PvRMC-1 的表位的天然免疫原性，因为其在嵌合结构中的维持。在应答者中，观察到由 IgG1（70%）和 IgG3（69%）介导的主要细胞亲嗜性反应。IgM 水平与年龄和在流行地区的居住时间呈负相关（<0.01）。相比之下，IgG 和 IgM 反应性指数相互正相关，并且两者均与上次疟疾发作的时间呈负相关。结论：该研究表明 PvRMC-1 成功表达并被天然抗体靶向，为构建多阶段嵌合重组蛋白以及利用天然获得的抗体验证构建提供了重要见解。
