Rocha Mariana Vilela, Françoso Kátia Sanches, Lima Luciana Chagas, Camargo Tarsila Mendes, Machado Ricardo L D, Costa Fabio T M, Rénia Laurent, Nosten Francois, Russell Bruce, Rodrigues Mauricio M, Soares Irene S
Departamento de Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, São Paulo, SP, Brazil.
Divisão de Parasitologia, Instituto Evandro Chagas, Belém, PA, Brazil.
Vaccine. 2017 Apr 25;35(18):2463-2472. doi: 10.1016/j.vaccine.2017.03.023. Epub 2017 Mar 22.
Plasmodium vivax is the most widely distributed malaria species and the most prevalent species of malaria in America and Asia. Vaccine development against P. vivax is considered a priority in the global program for the eradication of malaria. Earlier studies have characterized the Apical Membrane Antigen 1 (AMA-1) ectodomain and the C-terminal region (19kDa) of the Merozoite Surface Protein 1 (MSP-1) of P. vivax as immunodominant antigens. Based on this characterization, we designed a chimeric recombinant protein containing both merozoite immunodominant domains (PvAMA1-MSP1). The recombinant PvAMA1-MSP1 was successfully expressed in Pichia pastoris and used to immunize two different mouse strains (BALB/c and C57BL/6) in the presence of the Poly (I:C) as an adjuvant. Immunization with the chimeric protein induced high antibody titers against both proteins in both strains of mice as detected by ELISA. Antisera also recognized the native proteins expressed on the merozoites of mature P. vivax schizonts. Moreover, this antigen was able to induce IFN-gamma-secreting cells in C57BL/6 mice. These findings indicate that this novel yeast recombinant protein containing PvAMA1 and PvMSP1 is advantageous, because of improved antibody titers and cellular immune response. Therefore, this formulation should be further developed for pre-clinical trials in non-human primates as a potential candidate for a P. vivax vaccine.
间日疟原虫是分布最广泛的疟原虫种类，也是美洲和亚洲最常见的疟疾种类。开发针对间日疟原虫的疫苗被视为全球疟疾根除计划的优先事项。早期研究已将间日疟原虫的顶端膜抗原1（AMA-1）胞外结构域和裂殖子表面蛋白1（MSP-1）的C末端区域（19kDa）鉴定为免疫显性抗原。基于这一特性，我们设计了一种包含两种裂殖子免疫显性结构域的嵌合重组蛋白（PvAMA1-MSP1）。重组PvAMA1-MSP1在毕赤酵母中成功表达，并在聚肌胞苷酸（Poly (I:C)）作为佐剂的情况下用于免疫两种不同的小鼠品系（BALB/c和C57BL/6）。通过ELISA检测发现，用该嵌合蛋白免疫可在两种小鼠品系中诱导产生针对这两种蛋白的高抗体滴度。抗血清还识别成熟间日疟原虫裂殖子上表达的天然蛋白。此外，这种抗原能够在C57BL/6小鼠中诱导分泌γ干扰素的细胞。这些发现表明，这种含有PvAMA1和PvMSP1的新型酵母重组蛋白具有优势，因为它提高了抗体滴度和细胞免疫反应。因此，这种制剂应进一步开发用于非人类灵长类动物的临床前试验，作为间日疟原虫疫苗的潜在候选物。
