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

描述（由申请人提供）： 本申请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（志贺氏菌、沙门氏菌和小肠结肠炎耶尔森氏菌）的广谱儿科疫苗。新生儿、婴儿和幼儿是人口中最脆弱的群体，他们可能无法耐受对成人有效的疫苗，也无法充分应答。我们将探索一种新的平台技术，该技术由无生命的、非转基因的乳酸乳球菌颗粒组成，称为革兰氏阳性增强子基质（GEM），该基质将被工程化以在颗粒表面上展示来自这些病原体中的每一种的III型分泌抗原。这些抗原展示颗粒将被组合以产生广谱疫苗。洛杉矶乳酸菌GEM颗粒（益生菌衍生物）具有突出的安全性特征，可经粘膜施用，具有强佐剂性质（肽聚糖包膜刺激先天免疫），高度稳定（消除对冷链的需要），易于制造且廉价。评估展示鼠疫耶尔森氏菌LcrV的GEM颗粒的初步研究表明，它们具有高度免疫原性，并在新生儿免疫的小鼠中赋予针对致死性细菌感染的完全保护。携带抗原的颗粒诱导稳健的粘膜以及全身性Th1型免疫。基于GEM的儿科疫苗可以预防食源性和水源性疾病，这将是一种重要的公共卫生工具，不仅可以用于生物防御，还可以用于预防学校和日托机构以及旅行者的肠道感染。这项工作将在四个目标进行。在目标1中，我们将构造L。展示志贺氏菌iPad和IpaB、沙门氏菌SipB和SipD以及耶尔森氏菌LcrV和YopB保护性抗原的乳酸菌GEM颗粒。每个颗粒将展示来自每个靶病原体的两种抗原，并且颗粒可以根据需要单独使用或组合使用（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方案和不同的攻击模型来检查它们的保护效力。在目标4中，我们将在稳定性和总体安全性方面表征最终产品，以满足研究性新药（IND）申请的要求。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，以在人类中测试这些疫苗。这项工作非常重要，因为它解决了对一种安全有效的儿科疫苗的需求，用于没有疫苗的破坏性食物和水传播疾病。我们是唯一一个研究L的使用的组织。乳杆菌GEM颗粒作为小儿肠疫苗。如果成功，这项工作将揭示一种预防婴儿传染病的新疫苗模式。本项目的目的是开发一种新的非生命的、非转基因的L。以乳酸菌为基础的多价疫苗，保护婴幼儿免受沙门氏菌、志贺氏菌和小肠结肠炎耶尔森氏菌（B类病原体）引起的疾病的侵害。来自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上。将在新生小鼠中检测免疫原性和保护效力。这种疫苗技术的优点包括：突出的安全性，对多种病原体的广泛保护，易于输送（粘膜接种）和简单廉价的生产。 相关性：本项目的目的是开发一种新型的无生命、非转基因的L。以乳酸菌为基础的多价疫苗，保护婴幼儿免受沙门氏菌、志贺氏菌和小肠结肠炎耶尔森氏菌（B类病原体）引起的疾病的侵害。来自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上。将在新生小鼠中检测免疫原性和保护效力。这种疫苗技术的优点包括：突出的安全性，对多种病原体的广泛保护，易于输送（粘膜接种）和简单廉价的生产。

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.