Broad spectrum Shigella subunit vaccine based on conserved proteins

基于保守蛋白的广谱志贺氏菌亚单位疫苗

• 批准号: 10549775
• 负责人: Marcela F Pasetti
• 金额: $ 53.13万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-02-04 至 2026-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10549775
• 关键词: 5 year old; Adjuvant; Adult; Affect; Animal Model; Antibiotic Resistance; Antibiotics; Antibodies; Antigens; Antimicrobial Resistance; Area; Attenuated; Cavia; Cell Culture Techniques; Cell-Free System; Cells; Child; Clinical; Clinical Research; Country; Data; Day center care; Developed Countries; Development; Diarrhea; Disease; Disease Outbreaks; Dysentery; Epidemiology; Evaluation; Goals; Growth; Human; Human Milk; IgG1; Immune Sera; Immunity; Immunization; Immunoglobulin G; Immunologics; Impaired cognition; In Vitro; Incidence; Infant; Infection; Inflammatory; Institution; Interruption; Intramuscular; Invaded; Laboratories; Life; Medical; Methods; Military Personnel; Modeling; Monoclonal Antibodies; Mothers; Mucous Membrane; Multi-Drug Resistance; Mus; Natural Immunity; Nature; O Antigens; Oral; Organism; Oryctolagus cuniculus; Phase; Placenta; Plasmids; Polysaccharides; Positioning Attribute; Production; Protein Biosynthesis; Proteins; Public Health; Reporting; Resources; Risk; Role; Rotavirus; Serotyping; Serum; Severities; Shigella; Shigella Infections; Shigella Vaccines; Subunit Vaccines; System; T cell response; Technology; Testing; Translating; Type III Secretion System Pathway; Vaccine Antigen; Vaccines; Virulence; Virulent; Vulnerable Populations; Work; aluminum sulfate; bioweapon; burden of illness; clinical development; clinical translation; clinically relevant; cost; diarrheal disease; disability; dosage; experimental study; genetic element; illness length; immunogenic; immunogenicity; in vivo evaluation; infection risk; innovation; low and middle-income countries; manufacture; manufacturing scale-up; mortality; new technology; novel; parenteral administration; phase 1 study; pre-clinical; prevent; prophylactic; protective efficacy; protein purification; resistant Shigella; screening; serological marker; success; tissue culture; tool; vaccine candidate

ABSTRACT Shigella spp. are a major global cause of diarrhea and dysentery. Children 2-5 years of age in low- and middle- income countries are the most affected. Mortality is second only to rotavirus among diarrheal diseases in young children, and repeated bouts of disease cause lifelong disability. In industrialized nations, Shigella outbreaks have occurred in day care centers and medical institutions. Shigella spp. rapidly acquire genetic elements that confer antimicrobial resistance. A safe, effective, and affordable vaccine could make a major public health impact, yet none is currently approved. Candidates based on the Shigella-O-antigen are in clinical development. However, that approach is impractical and costly, requiring multiple vaccines to prevent disease caused by Shigella strains with different O antigens. This proposal seeks to develop a safe, practical, and effective broad- spectrum Shigella vaccine based on highly conserved Shigella Type III secretion system (TTSS) proteins, invasion plasmid antigen (Ipa) B, IpaH, and the virulence antigen VirG (IcsA). Our laboratory was the first to report the high immunogenic and broad protective capacity of Shigella IpaB in mice, and the association of IpaB- and VirG- serum IgG (IgG1) levels with clinical protection against shigellosis in humans. Preliminary data in this application demonstrate that VirG also elicits potent and protective immunity. In addition, we have found that adults living in endemic regions who acquire natural immunity to Shigella have high levels of IpaB-, VirG-, and IpaH- serum antibodies. Maternal IgG against these proteins are more efficiently transferred to infants through the placenta as compared to IgG against the O-polysaccharide. High levels of antibodies are also present in breast milk. This robust maternally-derived immunity is consistent with the low incidence of infection at <6 months of life. Together, our findings provide a strong premise for the success of a broad-spectrum subunit (IpaB, IpaH, and/or VirG) Shigella vaccine. Given parenterally, this vaccine is expected to be well-tolerated and to elicit robust immunity in young children, the main target group. In Aim 1, we will purify and characterize Shigella IpaB, IpaH, and VirG using an innovative cell-free protein synthesis system. This technological breakthrough allows the production of high-quality vaccine antigens at large yield and can be easily scaled-up for manufacturing. In Aim 2, we will evaluate the capacity of IpaB, IpaH, and VirG to elicit protective immunity and to confer broad-spectrum protection in mice and guinea pigs. The proteins will be administered parenterally, alone or combined, with alum as adjuvant ‒ a strategy that can be readily translated to humans. In Aim 3, we will investigate the protective role of IpaB, IpaH, and VirG antibodies through passive transfer experiments in mouse and guinea pig infection models and specific steps of infection targeted by each antibody using in vitro cell culture. We have unique expertise, tools, and novel technology to produce a simple and efficacious new subunit vaccine to prevent multidrug-resistant Shigella. If successful, this concept could be easily tested in Phase I studies in humans.

抽象的 志贺氏菌是全球 2-5 岁中低龄儿童腹泻和痢疾的主要原因。 收入国家受影响最严重，在年轻人腹泻病中死亡率仅次于轮状病毒。 在工业化国家，志贺氏菌的爆发会导致儿童和疾病的反复发作，导致终身残疾。 志贺氏菌迅速获得遗传元件。 一种安全、有效且负担得起的疫苗可能会产生重大的公共卫生问题。 影响，但目前尚未批准基于志贺氏菌 O 抗原的候选药物。 然而，这种方法不切实际且成本高昂，需要多种疫苗来预防由 该提案旨在开发一种安全、实用、有效的广泛的志贺氏菌菌株。 基于高度保守的志贺氏菌 III 型分泌系统 (TTSS) 蛋白的谱志贺氏菌疫苗， 侵袭质粒抗原（Ipa）B、IpaH、毒力抗原VirG（IcsA）是我室率先发现的。 报告了志贺氏菌 IpaB 在小鼠中的高免疫原性和广泛的保护能力，以及 IpaB-的关联 VirG- 血清 IgG (IgG1) 水平对人类志贺氏菌病具有临床保护作用。 应用表明 VirG 还可以引发有效的保护性免疫。 生活在流行地区的成年人对志贺氏菌具有天然免疫力，其 IpaB-、VirG- 和 针对这些蛋白质的母体 IgG 抗体可以更有效地转移给婴儿。 与 IgG 相比，胎盘中也存在高水平的 O-多糖抗体。 这种强大的母源性免疫力与 6 个月以下的低感染率是一致的。 总之，我们的发现为广谱亚基（IpaB、IpaH、 和/或 VirG) 志贺氏菌疫苗通过肠胃外给药，预计该疫苗具有良好的耐受性并能产生强效效果。 幼儿是免疫力的主要目标群体。 在目标 1 中，我们将使用创新的无细胞蛋白来纯化和表征志贺氏菌 IpaB、IpaH 和 VirG 这一技术突破使得大规模生产高质量疫苗抗原成为可能。 在目标 2 中，我们将评估 IpaB、IpaH 和 IpaB 的容量。 VirG 可引发保护性免疫并为小鼠和豚鼠提供广谱保护。 将通过胃肠外给药，单独或联合使用明矾作为佐剂——这一策略可以很容易地实现 在目标 3 中，我们将通过研究 IpaB、IpaH 和 VirG 抗体的保护作用。 小鼠和豚鼠感染模型被动转移实验及针对性感染的具体步骤 我们拥有独特的专业知识、工具和新技术来生产每种抗体。 简单有效的新型亚单位疫苗可预防多重耐药志贺氏菌 如果成功的话，这一概念。 可以很容易地在人体的第一阶段研究中进行测试。