Alum-absorbed subunit vaccine to prevent intestinal amebiasis

预防肠道阿米巴病的明矾吸收亚单位疫苗

基本信息

批准号：
8303054
负责人：
David M. Lyerly
金额：
$ 30万
依托单位：
TECHLAB, INC.
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-07-16 至 2014-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8303054
关键词：
Adherence Africa Agreement Amebiasis Amebic colitis Animal Model Antibody Formation Antigens Asia Bacterial Adhesins Biomedical Research Bioterrorism CD4 Positive T Lymphocytes Categories Cells Cessation of life Child Clinical Trials Collaborations Cyclic GMP DNA Developing Countries Development Diagnostic tests Diarrhea Dose Drug Formulations Dysentery Effectiveness Endocytosis Endotoxins Entamoeba histolytica Enteral Environment Enzyme-Linked Immunosorbent Assay Epitopes Escherichia coli FDA approved Food Food Supply Frequencies Future Gal-GalNAc Goals Hour Human Immunity Immunization Immunoglobulin A Infection Intellectual Property Interferon Type II Intestinal Diseases Intestines Laboratories Latin America Lectin Legal patent Licensing Life Liver Liver Abscess Maps Measures Mediating Modeling Mus Myron National Institute of Allergy and Infectious Disease Organ Paper Parasites Phase Phase I Clinical Trials Procedures Process Production Proteins Publishing Quality Control Reagent Recombinant Vaccines Recombinants Regimen Research Research Personnel Rodent Model Serum Small Business Innovation Research Grant Staging Subunit Vaccines Surface Antigens Surrogate Markers T cell response Testing Time Toxic effect United States National Institutes of Health Universities Vaccine Antigen Vaccines Virginia Virulence Water Water Supply Work aluminum sulfate biodefense bone cGMP production cell mediated immune response cytotoxicity immunogenicity innovation killings mouse model neutralizing antibody novel pathogen pre-clinical preclinical study prevent protective efficacy prototype response scale up transmission process vaccine development vaccine efficacy vaccine evaluation

项目摘要

DESCRIPTION (provided by applicant): We propose to produce a subunit vaccine for Entamoeba histolytica and test it in mice for immunogenicity and for protection from intestinal amebiasis. Entamoeba histolytica is a Category B NIH Biodefense pathogen due to its low infectious dose and food and water-bone transmission, and an important cause of diarrhea in children in Africa, Asia and Latin America. The candidate vaccine antigen is the LecA domain of the E. histolytica Gal/GalNAc lectin that mediates parasite adherence and contact-dependent cytotoxicity. LecA contains all of the virulence neutralizing antibody epitopes of the native Gal/GalNAc lectin, and in fact a surrogate marker of immunity in children is intestinal IgA against LecA. Feasibility of our approach is underscored by the effectiveness of LecA in many investigators' laboratories as a vaccine in rodent models of amebiasis. Innovative aspects of the proposed research include production of the first vaccine against an enteric parasite, the use of an antigen (LecA) where virulence-neutralizing epitopes have been mapped, and utilization of the novel mouse model of amebic colitis for efficacy studies. Our approach will be to conduct preclinical development of the LecA vaccine formulated in alum. Preliminary studies published from our group have demonstrated the effectiveness of this prototype vaccine in the murine model. Two specific aims are proposed to conduct this work: In Specific Aim 1, we will express and purify from E. coli the LecA fragment of the Gal/GalNAc lectin using standard operating procedures that are scalable to cGMP. We will quality control the purified protein for endotoxin, DNA, and contaminating host cell proteins, absorb it to alum and test its stability and lot-to-lot variability. TechLab will be entirely responsible for Aim 1. In Specific Aim 2, we will compare different dosing intervals and amounts to examine the immunogenicity, both cellular and humoral, of the alum-absorbed LecA parenteral vaccine for (a) the magnitude of an antigen-specific pre-challenge IFN-g+, CD4+ T cell response to LecA, and mucosal and serum antibody responses, and (b) vaccine efficacy and durability. UVA will perform all immunizations, cell mediated immune response tests, humoral responses, and vaccine trials. TechLab will provide the LecA alum-absorbed vaccine and reagents for ELISA analysis of humoral responses. The research proposed builds on the 15 year collaboration in amebiasis of the investigators, Dr. Lyerly of TechLab and Dr. Petri (the discoverer of the Gal/GalNAc lectin) from UVa. The proximity of TechLab and UVa (a 2 hour drive on I-81) facilitates this collaborative environment. Successful completion of these studies will ready the LecA vaccine for cGMP manufacture and toxicity studies (required for future phase I human clinical trials), maximize its immunogenicity and efficacy, and thereby set the stage for phase I clinical trials of an amebiasis vaccine for humans.

描述（由申请人提供）：我们建议生产一种溶组织内阿米巴亚单位疫苗，并在小鼠中测试其免疫原性和预防肠道阿米巴病的能力。溶组织内阿米巴因其感染剂量低、可通过食物和水骨传播而被列为 NIH 生物防御 B 类病原体，是非洲、亚洲和拉丁美洲儿童腹泻的重要原因。候选疫苗抗原是溶组织内阿米巴 Gal/GalNAc 凝集素的 LecA 结构域，可介导寄生虫粘附和接触依赖性细胞毒性。 LecA 含有天然 Gal/GalNAc 凝集素的所有毒力中和抗体表位，事实上，儿童免疫的替代标志物是针对 LecA 的肠道 IgA。 LecA 在许多研究人员的实验室中作为阿米巴病啮齿动物模型疫苗的有效性强调了我们方法的可行性。拟议研究的创新方面包括生产第一种针对肠道寄生虫的疫苗，使用已绘制毒力中和表位的抗原（LecA），以及利用新型阿米巴结肠炎小鼠模型进行功效研究。我们的方法是对明矾配制的 LecA 疫苗进行临床前开发。我们小组发表的初步研究已经证明了这种原型疫苗在小鼠模型中的有效性。开展这项工作有两个具体目标：在具体目标 1 中，我们将使用可扩展到 cGMP 的标准操作程序从大肠杆菌中表达和纯化 Gal/GalNAc 凝集素的 LecA 片段。我们将对纯化蛋白的内毒素、DNA 和污染宿主细胞蛋白进行质量控制，将其吸收到明矾中并测试其稳定性和批次间变异性。 TechLab 将完全负责目标 1。在具体目标 2 中，我们将比较不同的给药间隔和剂量，以检查明矾吸收的 LecA 肠外疫苗的细胞和体液免疫原性，以了解 (a) 抗原的大小 - (b) 疫苗功效和持久性。 UVA 将执行所有免疫接种、细胞介导的免疫反应测试、体液反应和疫苗试验。 TechLab 将提供 LecA 明矾吸收疫苗和用于体液反应 ELISA 分析的试剂。拟议的研究建立在研究人员 TechLab 的 Lyerly 博士和 UVa 的 Petri 博士（Gal/GalNAc 凝集素的发现者）15 年的阿米巴病合作基础上。 TechLab 和 UVa 毗邻（沿 I-81 行驶 2 小时），有利于这种协作环境。这些研究的成功完成将为LecA疫苗的cGMP生产和毒性研究（未来一期人体临床试验所需）做好准备，最大限度地提高其免疫原性和功效，从而为人类阿米巴病疫苗一期临床试验奠定基础。