Accelerating Malaria Vaccines with a Custom Preclinical Humanized Mouse Model Platform

利用定制的临床前人源化小鼠模型平台加速疟疾疫苗的研发

• 批准号: 10418949
• 负责人: Facundo Damian Batista
• 金额: $ 70.45万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-03-01 至 2027-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10418949
• 关键词: 5 year old; Affinity; Animal Model; Anti-malarial drug resistance; Antibodies; Antigens; Automobile Driving; B-Cell Activation; B-Cell Antigen Receptor; B-Lymphocytes; Cell Separation; Cells; Cessation of life; Child; Clinical; Clinical Trials; Communities; Custom; Data; Development; Drug Controls; Engineering; Epitopes; Erythrocytes; Etiology; Evaluation; Frequencies; Generations; Genetically Engineered Mouse; Goals; Growth; HIV-2; Health Priorities; Human; Humoral Immunities; Immune; Immune response; Immunization; Immunoglobulin Somatic Hypermutation; Infection; Insecticides; Knock-in; Knock-in Mouse; Length; Malaria; Malaria Vaccines; Modeling; Monoclonal Antibodies; Mus; Pathway interactions; Peptides; Persons; Physiological; Plasmodium falciparum; Preclinical Testing; Protein Region; Proteins; Resources; Series; Site; Sporozoites; Structure of germinal center of lymph node; Surface; Therapeutic; Time; Vaccine Design; Vaccine Research; Vaccines; Validation; Variant; candidate validation; circumsporozoite protein; experimental study; global health; humanized mouse; immunogenicity; improved; in vivo; innovation; mouse model; novel; pre-clinical; prevent; protective allele; response; screening; single cell sequencing; success; technological innovation; tool; vaccination strategy; vaccine candidate; vaccine evaluation; vaccine immunogenicity; vector control

Project Abstract There were 229 million cases of malaria in 2019, leading to 409,000 deaths; effective vaccines are a global health priority. Animal models capable of prefiguring the human immune response are a vital component of the preclinical testing of vaccines. The major goal of this proposal is to apply the Batista lab's technical innovations in the rapid generation of mice with B cells bearing human B cell receptors (BCRs) to create new platforms for malaria immunogen screening and development. Vaccines targeting the infectious sporozoite stage could inhibit the establishment of clinical malaria, and sporozoite surfaces are densely covered by circumsporozoite protein (CSP); the most advanced current vaccines in human trials display regions of this protein, and we intend to use our mouse platforms to improve their targeting. For Aim 1, we will use our existing mouse model, which expresses the inferred germline version of a potent monoclonal antibody (mAb) currently in clinical trials, CIS43. Using an immunofocused approach, presenting a conserved junctional epitope between the N-terminus and the central repeat region of CSP, we have not only recapitulated the ontogeny of this potent mAb, but have also elicited variant antibodies that are even more effective in malaria challenge experiments. We intend to deep mine this effective platform with immunizations by variable-length junctional epitope peptides to 1) identify the most promising candidate junctional epitope immunogens for inclusion in vaccine design and 2) identify protective matured antibodies with potential clinical utility. In our models, B cells bearing humanized BCRs are titrated to low levels to mimic human physiological conditions. For Aim 2, we will use the CSP full-length and partial probes we have developed for characterizing our mouse models, in tandem with single-cell sequencing, to explore the frequencies of precursor B cells in humans. We will use these numbers to improve the precision of our mouse platform, titrating the humanized cells to more exactingly accurate levels. Finally, in Aim 3, we will take this immunofocusing approach to other regions of the CSP protein by creating a new series of mice expressing the precursor sequences of human antibodies to other subdomains of CSP. We will use this mouse platform to study the immunogenicity of peptides consisting of various sections of the CSP protein, with the goal of identifying the ideal epitope, or combination of epitopes, to elicit robust immune responses. We will enhance our models by moving multiple strains of KI B cells to the same host to try immunogens against “mini-repertoires” of humanized B cells. By creating these new precision platforms for malaria, we intend to cut the time needed to validate potential vaccine candidates.

项目摘要 2019年，疟疾病例达2.29亿例，导致40.9万人死亡；有效的疫苗 是全球卫生优先事项。能够预测人类免疫反应的动物模型 是疫苗临床前测试的重要组成部分。该提案的主要目标是 将 Batista 实验室的技术创新应用于快速生成带有 B 细胞的小鼠 人类 B 细胞受体 (BCR) 为疟疾免疫原筛查和创建新平台 发展。针对感染性子孢子阶段的疫苗可以抑制其建立 临床疟疾，子孢子表面被环子孢子蛋白紧密覆盖 （CSP）；当前人体试验中最先进的疫苗显示了这种蛋白质的区域，我们 打算使用我们的鼠标平台来提高他们的定位能力。对于目标 1，我们将使用现有的 小鼠模型，表达强效单克隆抗体的推断种系版本 （mAb）目前正在进行临床试验，CIS43。使用免疫聚焦方法，提出了 CSP 的 N 末端和中央重复区域之间的保守连接表位，我们 不仅重现了这种强效单克隆抗体的个体发育，而且还引发了变异 在疟疾挑战实验中更有效的抗体。我们打算深挖 这个有效的平台通过可变长度的连接表位肽进行免疫1) 确定最有希望纳入疫苗的候选连接表位免疫原 设计和 2) 识别具有潜在临床实用性的保护性成熟抗体。在我们的模型中，B 携带人源化 BCR 的细胞被滴定至低水平以模拟人类生理条件。 对于目标 2，我们将使用我们开发的 CSP 全长和部分探针来表征 我们的小鼠模型与单细胞测序相结合，探索前体的频率 人类的 B 细胞。我们将使用这些数字来提高我们的鼠标平台的精度， 将人源化细胞滴定至更精确的水平。最后，在目标 3 中，我们将采取这个 通过创建一系列新的小鼠，对 CSP 蛋白的其他区域进行免疫聚焦方法 表达针对 CSP 的其他子结构域的人类抗体的前体序列。我们将 使用该小鼠平台研究由不同部分组成的肽的免疫原性 CSP 蛋白，目的是识别理想的表位或表位组合，以引发 强大的免疫反应。我们将通过移动多种 KI B 细胞株来增强我们的模型 到同一宿主，尝试针对人源化 B 细胞“迷你库”的免疫原。通过创建 这些新的疟疾精准平台，我们打算缩短验证潜力所需的时间 候选疫苗。