Design of a B cell tetramer to track PfMSP2-specific B cells

设计 B 细胞四聚体来追踪 PfMSP2 特异性 B 细胞

• 批准号: 10517511
• 负责人: Jason S Stumhofer
• 金额: $ 7.6万
• 依托单位: UNIV OF ARKANSAS FOR MED SCIS
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-11-01 至 2023-10-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10517511
• 关键词: Adjuvant; Alleles; Amyloid; Antibodies; Antibody Response; Antibody titer measurement; Antigen Targeting; Antigens; Antimalarials; Area; B-Cell Antigen Receptor; B-Lymphocytes; Binding; Blood; Carrier Proteins; Cells; Cellular biology; Cessation of life; Chimeric Proteins; Classification; Clinical; Communicable Diseases; Culicidae; Development; Disease; Enzyme-Linked Immunosorbent Assay; Epitopes; Family; Generations; Genetic Polymorphism; Goals; Growth; Human; Humoral Immunities; IgG1; Immune response; Immunity; Immunization; Immunize; Immunoglobulin Constant Region; Immunoglobulin G; Immunologist; In Vitro; Individual; Infection; Invaded; Length; Light; Malaria; Malaria Vaccines; Masks; Measurement; Mediating; Memory B-Lymphocyte; Monitor; Monoclonal Antibodies; Mus; Parasites; Peptides; Plasma Cells; Plasmablast; Plasmodium; Plasmodium falciparum; Play; Population; Production; Proteins; Protocols documentation; Public Health; Quil A; Reaction; Recombinant Proteins; Recombinants; Regimen; Role; Serum; Specificity; Structure of germinal center of lymph node; Subunit Vaccines; Surface; Testing; Time; Vaccination; Vaccines; Variant; acquired immunity; combat; cross reactivity; design; early phase clinical trial; experimental study; immunogenic; immunogenicity; improved; merozoite surface protein; pathogen; protective efficacy; protein expression; protein purification; public health relevance; response; tool; transmission process; vaccination strategy; vaccine candidate; vaccine platform; vaccine trial

Project Summary The protozoan parasite Plasmodium is the causative agent of malaria, which remains one of the most prominent public health challenges in the world today. Antibodies play a primary role in protection from severe disease caused by blood-stage infection. However, repeated infections over an extended period are required to induce protective humoral immunity. It is unclear if protective antibodies are derived from short-lived plasmablasts through an extrafollicular response or long-lived plasma cells via the germinal center. Induction of the latter is the primary goal of effective vaccines. While Plasmodium-specific antibodies are detectable in the serum of individuals with clinical malaria, the cell biology underlying these antibody responses remains unknown. Here we propose developing a Plasmodium-specific B cell tetramer to track antigen-specific B cell responses to close gaps in our understanding of the humoral response to Plasmodium. Using the blood-stage antigen, merozoite surface protein 2 (MSP2), a candidate antigen for a blood-stage malaria vaccine, we will generate two B cell tetramers, one containing a full-length recombinant P. falciparum MSP2 protein and another encompassing a chimeric PfMSP2/8 protein. The former can form fibrils in vitro, while the latter does not. Hence, we predict the chimeric protein will offer such benefits as increased stability over time and the identification of a greater number of MSP2-specific B cells that bind a broader number of epitopes across PfMSP2 than a tetramer composed solely of rPfMSP2. In sub-aim 1, we will monitor MSP2 fibril formation and determine each B cell tetramer's ability to recognize antigen-specific B cells ex vivo after immunization of mice with either rPfMSP2 or rPfMSP2/8. Then in sub-aim 2, we will confirm the specificity of the B cells for binding MSP2 by ELISA through the generation of monoclonal antibodies based on the B-cell receptor sequences of tetramer positive B cells. Confirmation of the B cell tetramers' binding specificity is essential before using them to identify MSP2-specific B cells in the blood of individuals from malaria endemic areas or individuals participating in vaccine studies.

项目概要 原生动物寄生虫疟原虫是疟疾的病原体，疟疾仍然是最常见的疟疾之一。 当今世界面临的突出公共卫生挑战。抗体在预防严重疾病方面发挥主要作用 由血液阶段感染引起的疾病。但需要长时间反复感染 诱导保护性体液免疫。目前尚不清楚保护性抗体是否源自短命抗体 通过滤泡外反应产生浆母细胞，或通过生发中心产生长寿命浆细胞。感应 后者是有效疫苗的首要目标。虽然疟原虫特异性抗体可在 临床疟疾患者的血清中，这些抗体反应背后的细胞生物学仍然存在 未知。在这里，我们建议开发疟原虫特异性 B 细胞四聚体来追踪抗原特异性 B 细胞 弥补我们对疟原虫体液反应理解上的差距。使用血液阶段 抗原，裂殖子表面蛋白 2 (MSP2)，血期疟疾疫苗的候选抗原，我们将 生成两个 B 细胞四聚体，其中一个含有全长重组恶性疟原虫 MSP2 蛋白，并且 另一个包括嵌合PfMSP2/8蛋白。前者可以在体外形成原纤维，而后者则不能 不是。因此，我们预测嵌合蛋白将具有随着时间的推移而增加稳定性和 鉴定出更多数量的 MSP2 特异性 B 细胞，这些细胞可结合更广泛的表位 PfMSP2 不是仅由 rPfMSP2 组成的四聚体。在子目标 1 中，我们将监测 MSP2 原纤维的形成和 小鼠免疫后确定每个 B 细胞四聚体离体识别抗原特异性 B 细胞的能力 使用 rPfMSP2 或 rPfMSP2/8。然后在子目标 2 中，我们将确认 B 细胞结合的特异性 MSP2 通过 ELISA 生成基于 B 细胞受体序列的单克隆抗体 四聚体阳性 B 细胞。使用前必须确认 B 细胞四聚体的结合特异性 鉴定疟疾流行地区或个人血液中的 MSP2 特异性 B 细胞 参与疫苗研究。