Laboratório de Imunoparasitologia, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, (Fiocruz), Rio de Janeiro, RJ, Brazil.
Nuffield Department of Medicine, The Jenner Institute, The Henry Wellcome Building for Molecular Physiology, University of Oxford, Oxford, UK.
Sci Rep. 2020 Aug 20;10(1):14020. doi: 10.1038/s41598-020-70893-3.
Circumsporozoite protein (CSP) variants of P. vivax, besides having variations in the protein repetitive portion, can differ from each other in aspects such as geographical distribution, intensity of transmission, vectorial competence and immune response. Such aspects must be considered to P. vivax vaccine development. Therefore, we evaluated the immunogenicity of novel recombinant proteins corresponding to each of the three P. vivax allelic variants (VK210, VK247 and P. vivax-like) and of the C-terminal region (shared by all PvCSP variants) in naturally malaria-exposed populations of Brazilian Amazon. Our results demonstrated that PvCSP-VK210 was the major target of humoral immune response in studied population, presenting higher frequency and magnitude of IgG response. The IgG subclass profile showed a prevalence of cytophilic antibodies (IgG1 and IgG3), that seem to have an essential role in protective immune response. Differently of PvCSP allelic variants, antibodies elicited against C-terminal region of protein did not correlate with epidemiological parameters, bringing additional evidence that humoral response against this protein region is not essential to protective immunity. Taken together, these findings increase the knowledge on serological response to distinct PvCSP allelic variants and may contribute to the development of a global and effective P. vivax vaccine.
环子孢子蛋白（CSP）的间日疟变种，除了在蛋白重复部分存在差异外，在地理分布、传播强度、媒介效能和免疫反应等方面也存在差异。在开发间日疟疫苗时必须考虑到这些方面。因此，我们评估了对应于三种间日疟变种（VK210、VK247 和类间日疟变种）和 C 末端区域（所有 PvCSP 变种共有）的新型重组蛋白在巴西亚马逊地区自然疟疾暴露人群中的免疫原性。我们的结果表明，PvCSP-VK210 是研究人群中体液免疫反应的主要靶标，表现出更高的 IgG 反应频率和幅度。IgG 亚类谱显示亲细胞抗体（IgG1 和 IgG3）的流行，这似乎在保护性免疫反应中起着重要作用。与 PvCSP 等位变种不同，针对蛋白 C 末端区域产生的抗体与流行病学参数无关，这进一步表明针对该蛋白区域的体液反应对于保护性免疫不是必需的。综上所述，这些发现增加了对不同 PvCSP 等位变种的血清学反应的认识，并可能有助于开发全球有效的间日疟疫苗。
