Discovery and preclinical evaluation of Plasmodium falciparum and P. vivax coiled coil antigens for malaria vaccine development

用于疟疾疫苗开发的恶性疟原虫和间日疟原虫卷曲螺旋抗原的发现和临床前评估

• 批准号: 10079466
• 负责人: Socrates Herrera Valencia
• 金额: $ 38.26万
• 依托单位: CAUCASECO SCIENTIFIC RESEARCH CENTER
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-01-03 至 2023-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10079466
• 关键词: Adjuvant; Animal Model; Animals; Antibodies; Antibody Response; Antibody titer measurement; Antibody-mediated protection; Antigens; Aotus primate; Area; Bioinformatics; Biological Assay; Blood; Cessation of life; Chemicals; Circular Dichroism; Circular Dichroism Spectroscopy; Clinical; Coiled-Coil Domain; Control Animal; Country; Data; Development; Enzyme-Linked Immunosorbent Assay; Epitopes; Erythrocytes; Evaluation; Genome; Goals; Growth; High Pressure Liquid Chromatography; Human; Immune response; Immune system; Immunity; Immunization; Immunize; Immunoglobulin G; Immunologics; In Vitro; Incidence; Individual; Infection; Malaria; Malaria Vaccines; Mass Spectrum Analysis; Methods; Monkeys; Mus; Parasitemia; Parasites; Peptide Synthesis; Peptide antibodies; Peptides; Phagocytosis; Plasmodium; Plasmodium falciparum; Plasmodium vivax; Preparation; Primates; Process; Protein Fragment; Proteins; Proteome; Public Health; Recombinants; Respiratory Burst; Risk; Rodent; Solid; Specificity; Sterility; Structure; Synthetic Antigens; Testing; Vaccines; aqueous; base; cost effective; cross reactivity; design; disorder risk; efficacy study; experience; experimental study; immunogenic; immunogenicity; improved; in silico; in vitro Assay; in vivo; inhibiting antibody; innovation; manufacturing facility; nonhuman primate; novel; novel vaccines; peptide vaccination; preclinical evaluation; protective efficacy; protein structure; screening; success; tool; vaccine candidate; vaccine development

PROJECT SUMMARY/ABSTRACT Despite the great global public health importance, malaria vaccine development has been slow with only a handful of candidates under development and the most advanced displaying modest efficacy. The current use of bioinformatics for genome/proteome screening, animal models, and more efficient manufacturing facilities for recombinant/synthetic antigens could significantly accelerate the development of novel vaccines. We propose to use these advances to identify and develop vaccine candidates targeting both, Plasmodium falciparum and P. vivax parasites, responsible for >99% of the malaria cases worldwide. Alpha-helical coiled-coil motifs, protein structures widely distributed in the Plasmodium proteomes known to spontaneously fold in aqueous solution, are able to induce antibodies that inhibit parasite growth in vitro. We previously in silico identified 220 proteins in both parasite proteomes, 170 of which were synthesized and tested. High antigenicity with human sera from endemic areas, and immunogenicity in mice led to selection of 145 fragments. Several of them displayed significant P. falciparum/P. vivax cross reactivity, and importantly in vitro parasite inhibition activity, which correlated with malaria clinical immunity. Furthermore, mice immunization with a P. falciparum poly-epitope construct (Pf-181) maintained individual epitopes specificity and parasite inhibitory activity. Our general hypothesis is that “Plasmodium poly-epitope constructs containing cross-reacting α-helical coiled-coil motifs induce protection in monkey against homologous and heterologous parasite challenges. The overall goal is to determine the vaccine potential of P. falciparum and P. vivax erythrocytic synthetic poly-epitope constructs containing α-helical coiled-coil motifs. This goal will be approached through the following specific aims: 1) Design, synthesis and characterization of P. falciparum and P. vivax poly-epitope constructs containing α-helical coiled-coil motifs; 2) Evaluation of the immunogenicity and protective efficacy of selected P. falciparum and P. vivax poly-epitope constructs against homologous and heterologous parasite challenges in Aotus monkeys; 3) In vitro characterization of α-helical coiled-coil fragments/constructs and immune responses elicited by animal immunization. Methods proposed are: a) F-moc peptide synthesis of poly-epitope constructs, followed by HPLC purification, mass spectrometry (MS) and circular dichroism (CD) analyses; b) Monkey immunization with selected poly-epitope constructs and evaluation of protective efficacy to homologous and heterologous challenges using P. falciparum (Santa Lucia) and P. vivax (Sal-I) parasite strains; c) ELISA and IFAT test of sera from immunized animals; d) antibody functional in vitro assays (GIA, ADRB,OPA).The innovation of this study is the highly efficient and cost-effective approach, using a comprehensive rational and rigorous epitope down- selection of hundreds of protein fragments from in silico epitope identification in Plasmodium proteomes for poly- epitope design and evaluation of their protective efficacy studies in monkeys. It will accelerate the development of malaria vaccines for human use.

项目摘要/摘要 尽管全球公共卫生的重要性很高，但疟疾疫苗的开发一直很慢，只有一个 正在开发的少数​​候选人和最先进的效率。当前用途 用于基因组/蛋白质组筛查，动物模型和更有效制造设施的生物信息学的 重组/合成抗原可以显着加速新型疫苗的发展。我们建议 利用这些进步来识别和发展针对靶向疫苗的候选疫苗，疟原虫恶性疟原虫和P。 Vivax寄生虫，全球造成99％的疟疾病例。 α-螺旋线圈序列，蛋白质 广泛分布在已知在水溶液中折叠的质子蛋白质组中的结构， 能够诱导在体外抑制寄生虫生长的抗体。我们以前在计算机中确定了220种蛋白质 在两个寄生虫蛋白质组中，其中170个蛋白质组织进行了合成和测试。与人类血清的高抗原性来自 小鼠的内在区域和免疫原性导致选择了145个片段。其中几个显示了 大型恶性疟原虫/p。 Vivax交叉反应性，重要的是体外寄生虫抑制活性，这 与疟疾临床免疫相关。此外，小鼠用恶性疟原虫多发质免疫抑制 构造（PF-181）保持单个表位特异性和寄生虫抑制活性。我们的将军 假设是“含有交叉反应的α-螺旋线圈基序的疟原虫构造 诱导猴子的保护免受同源和异源寄生虫的挑战。总体目标是 确定恶性疟原虫和疟原虫红细胞合成的多聚蛋白构造的疫苗电位 包含α-螺旋盘线圈基序。该目标将通过以下特定目的实现：1） 含有α-螺旋的恶性疟原虫和拟曲霉的设计，合成和表征 盘绕螺旋的图案； 2）评估选定的恶性疟原虫和P.的免疫原性和受保护的效率。 在AOTUS猴子中，可抵抗同源和异源寄生虫挑战的体内多质构造； 3） α-螺旋线圈片段/构建体的体外表征和免疫复杂由动物引起 免疫。提出的方法是：a）f-moc肽合成多发质构建体，其次是HPLC 纯化，质谱法（MS）和圆形二科（CD）分析； b）猴子免疫 选定的多质构建体以及对同源和异源的受保护效率的评估 使用恶性疟原虫（Santa Lucia）和Vivax（Sal-i）寄生虫菌株面临的挑战； c）ELISA和IFAT测试血清 免疫动物； D）抗体在体外评估（GIA，ADRB，OPA）。 是一种高效且具有成本效益的方法，使用全面的理性和严格的表位下调 从疟原虫蛋白质中的硅表位鉴定中选择数百个蛋白质片段 猴子中其受保护效率研究的表位设计和评估。它将加速发展 用于人类使用的疟疾疫苗。