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

• 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
• 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

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）：我们建议生产用于溶解疗法的亚基疫苗，并在小鼠中对其进行免疫原性和保护肠道症进行测试。 Entamoeba Hissolytica由于其低传染性剂量和食物和水骨传播而成为BNIH生物化病原体类别，并且是非洲，亚洲和拉丁美洲儿童腹泻的重要原因。候选疫苗抗原是介导寄生虫依从性和接触依赖性细胞毒性的溶组织溶液蛋白的LECA结构域。 LECA包含所有中和抗体表位的毒力表位，实际上，儿童免疫的替代标志是针对LECA的肠道IgA。 LECA在许多研究者的实验室中作为疫苗模型中的疫苗的有效性强调了我们方法的可行性。 拟议的研究的创新方面包括针对肠寄生虫的第一种疫苗，使用抗原（LECA）的使用，其中已经映射了毒力性中和表位，并利用了新型的amebic结肠炎小鼠模型用于有效性研究。 我们的方法是进行明矾制造的LECA疫苗的临床前开发。我们小组发表的初步研究证明了该原型疫苗在鼠模型中的有效性。提出了两个具体的目的来进行这项工作：在特定的目标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。我们将质量控制内毒素，DNA和污染宿主细胞蛋白的纯化蛋白质，吸收其以明矾并测试其稳定性和大量对局部变异性。 TechLab将完全负责目标1。在特定的目标2中，我们将比较不同的给药间隔和数量，以检查（alum-absor-abrum-abrum-abrum-abrum-abrum-abrumant和and themoral）的免疫原性（a）的抗原特异性的抗原特异性抗原pre-challenge pre-challenge pre-challenge ifn-g+，cd4+ ter ter cd4+ ter clody and lec和muca和muca和muca和muca and lec和muca和muca，mucs and muca，m。疫苗功效和耐用性。 UVA将执行所有免疫，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校友吸收的疫苗和试剂，用于ELISA的体液反应分析。 这项研究提出的是基于UVA的研究Lyerly的Amebiasis合作15年的合作。 TechLab和UVA的接近度（在I-81上开车2小时）促进了这种协作环境。 这些研究的成功完成将为CGMP生产和毒性研究（未来I期人类临床试验所必需的LECA疫苗），最大程度地提高其免疫原性和功效，从而为人类的AMEBIASIS疫苗的I期临床试验奠定了基础。