A. L. lactis-based vaccine for children with broad spectrum for enteric pathogens

描述(由申请人提供)： 这项应用的目的是开发一种针对B类生物防御食品和水传播病原体的广谱儿科疫苗：志贺氏菌、沙门氏菌和小肠结肠炎耶尔森菌。新生儿、婴儿和幼儿属于人口中最脆弱的群体，他们可能无法耐受，也不能对对成人有效的疫苗产生足够的反应。我们将探索一种新的平台技术，由非生物、非转基因的乳酸乳球菌颗粒组成，命名为革兰氏阳性增强器矩阵(GEM)，它将被设计成在颗粒表面展示来自每一种病原体的III型分泌抗原。这些展示抗原的颗粒将被结合起来，生产出一种广谱疫苗。乳酸乳杆菌宝石颗粒(益生菌衍生物)具有出色的安全性，可在粘膜内给药，具有强大的佐剂特性(肽聚糖包膜刺激天然免疫)，高度稳定(不需要冷链)，易于制造，且价格低廉。对显示鼠疫耶尔森氏菌LcrV的GEM颗粒的初步研究表明，它们具有高度的免疫原性，并对作为新生儿免疫的小鼠提供充分的保护，防止致命的细菌感染。携带抗原的颗粒诱导了强大的粘膜和系统Th1型免疫。一种可以预防食物和水传播疾病的基于宝石的儿科疫苗将是一种重要的公共卫生工具，不仅可以用于生物防御，还可以防止学校和日托机构以及旅行者的肠道感染。这项工作将在4个目标下进行。在目标1中，我们将构建表达志贺氏菌IPAD和IPAB、沙门氏菌SipB和SipD以及耶尔森氏菌LcrV和YopB保护性抗原的乳酸乳杆菌宝石颗粒。每个颗粒将显示来自每个目标病原体的两个抗原，这些颗粒可以单独使用，也可以根据需要组合使用(以多价形式)。在目标2中，我们将在不同的动物模型中进行研究，以证明候选疫苗的免疫原性。在目标3中，我们将使用优化的免疫计划和不同的挑战模型来检查它们的保护效果。在目标4中，我们将从稳定性和总体安全性方面对最终产品进行表征，以满足研究新药(IND)应用的要求。在这个阶段，我们将开始制定临床开发计划，并将寻求资金来源，在人体上测试这些疫苗。拟议的工作意义重大，因为它解决了对没有疫苗可用的破坏性食物和水传播疾病的安全和有效的儿科疫苗的需求。我们是唯一一个研究乳酸乳杆菌宝石颗粒用作儿科肠道疫苗的小组。如果成功，这项工作将揭开一种预防婴儿传染病的新疫苗范例。本项目的目的是开发一种新型非生物、非转基因乳酸乳杆菌多价疫苗，以保护婴幼儿免受沙门氏菌、志贺氏菌和小肠结肠炎耶尔森菌(B类病原体)引起的疾病。这些病原体的保守的保护性III型分泌蛋白将显示在颗粒表面。将在作为新生儿免疫的小鼠身上测试免疫原性和保护效果。这种疫苗技术的优势包括：突出的安全性、对多种病原体的广泛保护、易于传递(粘膜疫苗接种)以及简单和廉价的生产。 相关性：本项目的目的是开发一种基于乳酸乳杆菌的新型非生物、非转基因多价疫苗，以保护婴幼儿免受沙门氏菌、志贺氏菌和小肠结肠炎耶尔森菌(B类病原体)引起的疾病。这些病原体的保守的保护性III型分泌蛋白将显示在颗粒表面。将在作为新生儿免疫的小鼠身上测试免疫原性和保护效果。这种疫苗技术的优势包括：突出的安全性、对多种病原体的广泛保护、易于传递(粘膜疫苗接种)以及简单和廉价的生产。

DESCRIPTION (provided by applicant): The purpose of this application is the development of a broad-spectrum pediatric vaccine against Category B Biodefense food and water borne pathogens: Shigella, Salmonella and Yersinia enterocolitica. Newborns, infants and young children are among the most vulnerable groups of the population who may not tolerate, neither respond adequately to vaccines that work in human adults. We will explore a novel platform technology consisting of nonliving, non-genetically modified, Lactococcus lactis particles, designated Gram-positive Enhancer Matrix (GEM) that will be engineered to display Type III secretion antigens from each of these pathogens on the particle surface. These antigen-displaying particles will be combined to produce a broad spectrum vaccine. The L. lactis GEM particles (probiotic derivatives) have an outstanding safety profile, can be administered mucosally, have strong adjuvant properties (the peptidoglycan envelope stimulates innate immunity), are highly stable (eliminating the need for cold chain), easy to manufacture and inexpensive. Preliminary studies evaluating GEM particles displaying Yersinia pestis LcrV showed that they are highly immunogenic and confer full protection against lethal bacterial infection in mice immunized as newborns. The antigen-carrying particles induced robust mucosal as well as systemic Th1 type immunity. A pediatric GEM-based vaccine that can protect against food and water borne diseases would be an important public health tool for purposes of biodefense but also to prevent enteric infection in school and day care settings, as well as for travelers. The work will be conducted in 4 Aims. In Aim 1 we will construct the L. lactis GEM particles displaying Shigella IpaD and IpaB, Salmonella SipB and SipD and Yersinia LcrV and YopB protective antigens. Each particle will display two antigens from each of the target pathogens and the particles can be used alone or combined (in a multivalent format) as needed. In Aim 2 we will perform studies in different animal models to demonstrate immunogenicity of the vaccine candidates. In Aim 3 we will examine their protective efficacy using optimized immunization schedules and different challenge models. In Aim 4 we will characterize the final product in terms of stability and overall safety to satisfy requirements for an Investigational New Drug (IND) application. At this stage we will start developing a clinical development plan and will seek funding sources to test these vaccines in humans. The work proposed is highly significant, as it addresses the need for a safe and effective pediatric vaccine for devastating food and water borne diseases for which no vaccines are available. We are the only group investigating the use of L. lactis GEM particles as pediatric enteric vaccines. If successful, this work will unravel a new vaccine paradigm to prevent infectious diseases in infants. The purpose of this project is to develop a novel non-living, non-genetically modified L. lactis-based multivalent vaccine to protect infants and young children against disease caused by Salmonella, Shigella and Yersinia enterocolitica (Category B pathogens). Conserved protective type III secretion proteins from these pathogens will be displayed on the particle surface. Immunogenicity and protective efficacy will be tested in mice immunized as newborns. Advantages of this vaccine technology include: an outstanding safety profile, broad protection against multiple pathogens, ease of delivery (mucosal vaccination) and simple and inexpensive production. Relevance: The purpose of this project is to develop a novel non-living, non-genetically modified L. lactis-based multivalent vaccine to protect infants and young children against disease caused by Salmonella, Shigella and Yersinia enterocolitica (Category B pathogens). Conserved protective type III secretion proteins from these pathogens will be displayed on the particle surface. Immunogenicity and protective efficacy will be tested in mice immunized as newborns. Advantages of this vaccine technology include: an outstanding safety profile, broad protection against multiple pathogens, ease of delivery (mucosal vaccination) and simple and inexpensive production.