Synthesis of immunogenic glycolipopeptides for the development of vaccines for Ch

用于开发 Ch 疫苗的免疫原性糖脂肽的合成

• 批准号: 7660941
• 负责人: Katja Michael
• 金额: $ 22.45万
• 依托单位: UNIVERSITY OF TEXAS EL PASO
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-03-20 至 2011-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7660941
• 关键词: Accounting; Adjuvant; Animals; Antibodies; Antibody Formation; Antigen Presentation; Antigens; B-Lymphocyte Epitopes; Binding; Biological Assay; Blood; CD4 Positive T Lymphocytes; CD8B1 gene; Carbohydrates; Carrier Proteins; Cell surface; Cells; Central America; Chagas Disease; Chronic; Combined Vaccines; Communicable Diseases; Complex; Cytolysis; Cytotoxic T-Lymphocytes; Data; Dendritic Cells; Development; Disease; Epitopes; Evaluation; Flow Cytometry; Fluorescence Microscopy; Galactosides; Galactosyltransferases; Gastrointestinal tract structure; Glycoconjugates; Glycoproteins; Goals; Haptens; Helper-Inducer T-Lymphocyte; Human; Immune response; Immunization; Immunotherapy; In Vitro; Individual; Invaded; Keyhole Limpet Hemocyanin; Knock-out; Laboratories; Lead; Life; Link; Lipids; Lytic; Marketing; Mastigophora; Membrane Glycoproteins; Methods; Modeling; Molecular; Mucins; Mus; Neoglycoproteins; Oligosaccharides; Parasites; Patients; Peptides; Pharmaceutical Preparations; Pilot Projects; Polysaccharides; Proteins; Public Health; Research; Research Project Grants; Risk; Rosa; Screening procedure; Serum; Staging; Structure; Synthetic Vaccines; T-Lymphocyte Epitopes; Testing; Tissues; Toll-like receptors; Translational Research; Trypanosoma cruzi; Vaccination; Vaccines; base; carbohydrate structure; chemotherapy; cytotoxicity; design; glycolipopeptide; glycosyltransferase; immunogenic; interest; killings; macrophage; programs; public health relevance; reproductive; response; sucking; uptake; vaccine candidate; vaccine development; vector

DESCRIPTION (provided by applicant): Trypanosoma cruzi is a protozoan parasite that causes Chagas disease in Central America. Over 11 million people are infected, and up to 50,000 die each year due to complications during the chronic stage of the disease. No effective drugs exist to treat chronic Chagas disease, and no vaccination is available to date. The long-term goal of this pilot project is to obtain critical exploratory vaccine/immune response data that will ultimately lead to an effective vaccine that provides full protection to immunized individuals. The P.I.'s approach differs fundamentally from others' attempts to develop a vaccine for Chagas disease by the idea of incorporating parasitic cell surface carbohydrate epitopes into fully synthetic vaccines. The glycocalix of trypomastigotes, the infective forms of the parasite, contains large amounts of structurally heterogeneous glycans with terminal 1-galactosyl moieties, which are foreign to humans. Furthermore, the sera of Chagasic patients contain antibodies, known as anti-1-Gal, with a unique function, i.e. they cause lysis of trypomastigotes by recognition of 1-galactosyl epitopes. Therefore, it is hypothesized that the trypomastigotes' 1-galactosides are extremely immunogenic B-cell epitopes that elicit highly effective lytic antibodies. It is further hypothesized that a fully effective vaccine should elicit both, lytic antibodies as well as cytotoxic T-cells. Therefore, two types of synthetic vaccine candidates that contain different epitopes will be generated and used in combination. Five small synthetic oligosaccharide haptens with terminal 1-galactosides will be synthesized and conjugated to carrier proteins. The neoglycoproteins will be used for initial screening immunization of 1-1,3- galactosyltransferase knockout (11,3GalT-KO) mice, which in contrast to wild-type counterparts, are responsive to 1-galactosides, and are therefore a good model for humans. The sera of immunized animals will be tested for their ability to lyse trypomastigotes in vitro. The 1-galactoside epitopes that are capable of evoking such an immune response will then be used to generate potentially superior vaccines by incorporating them into fully synthetic glycolipopeptides. These conjugates will be designed to contain: (a) one or more 1- galactoside(s) as B-cell epitopes; (b) a CD4+ epitope for the activation of helper T-cells; and (c) a lipid moiety as an adjuvant that targets Toll-like receptors of dendritic cells. Another type of conjugate will consist of (a) a lipid; and (b) one or two Trypanosoma cruzi specific CD8+ T-cell epitopes to elicit cytotoxic T-cells. The humoral and cellular immune responses of mice to these potential vaccines will be studied. If successful, this exploratory research project will create the molecular basis for the development of the first effective human vaccine for Chagas disease, which would have a tremendous impact on public health, and may save thousands of lives in Central America. In addition, the described concept of fully synthetic vaccines may have a much broader relevance for translational research, as it may be applicable to other endemic parasitic and infectious diseases. PUBLIC HEALTH RELEVANCE: Chagas disease is a life-threatening disease in Central America that is transmitted by the blood- sucking triatome bug, and is caused by a unicellular parasite, Trypanosoma cruzi, that expresses certain immunogenic 1-galactosides on its cell surface. Our goal is to construct fully synthetic glycoconjugates that resemble the cell surface of the parasite, and test them in immunization studies in mice. The results of this research could lead to a vaccine which would have a tremendous impact on public health, not only by saving thousands of lives in Central America, but also by protecting individuals under risk in the U.S.

描述（申请人提供）：克氏锥虫是一种原生动物寄生虫，在中美洲引起恰加斯病。超过1 100万人受到感染，每年多达50 000人死于该疾病慢性期的并发症。目前没有治疗慢性恰加斯病的有效药物，迄今也没有疫苗接种。这一试点项目的长期目标是获得关键的探索性疫苗/免疫反应数据，这些数据将最终导致产生一种有效的疫苗，为免疫个体提供全面保护。私家侦探的方法从根本上不同于其他人试图通过将寄生细胞表面碳水化合物表位纳入完全合成疫苗的想法来开发恰加斯病疫苗。锥虫鞭毛体的糖杯，寄生虫的感染形式，含有大量的结构异质性聚糖与末端1-半乳糖基部分，这是外来的人类。此外，恰格曲病患者的血清含有称为抗1-Gal的抗体，其具有独特的功能，即它们通过识别1-半乳糖基表位而引起锥虫鞭毛体的溶解。因此，假设锥鞭毛体的1-半乳糖苷是引发高效裂解抗体的极免疫原性B细胞表位。进一步假设，完全有效的疫苗应引发裂解性抗体以及细胞毒性T细胞。因此，将产生并组合使用含有不同表位的两种类型的合成疫苗候选物。将合成五种具有末端1-半乳糖苷的小的合成寡糖半抗原并将其缀合至载体蛋白。新糖蛋白将用于1- 1，3-半乳糖基转移酶敲除（11，3GalT-KO）小鼠的初始筛选免疫，与野生型对应物相比，其对1-半乳糖苷有反应，因此是人类的良好模型。将检测免疫动物的血清在体外裂解锥虫鞭毛体的能力。能够引起这种免疫应答的1-半乳糖苷表位然后将用于通过将它们掺入完全合成的糖脂肽中来产生潜在的上级疫苗。这些缀合物将被设计为含有：（a）一种或多种1-半乳糖苷作为B细胞表位;（B）用于活化辅助T细胞的CD 4+表位;和（c）脂质部分作为靶向树突细胞的Toll样受体的佐剂。另一种类型的缀合物将由（a）脂质;和（B）一个或两个克氏锥虫特异性CD 8 + T细胞表位组成，以引发细胞毒性T细胞。将研究小鼠对这些潜在疫苗的体液和细胞免疫应答。如果成功，这一探索性研究项目将为研制第一种有效的人类南美锥虫病疫苗奠定分子基础，这将对公共卫生产生巨大影响，并可能挽救中美洲数千人的生命。此外，所描述的全合成疫苗的概念可能对转化研究具有更广泛的相关性，因为它可能适用于其他地方性寄生虫病和传染病。 公共卫生关系：查加斯病是中美洲的一种危及生命的疾病，其由吸血锥虫传播，并且由单细胞寄生虫克氏锥虫引起，克氏锥虫在其细胞表面上表达某些免疫原性1-半乳糖苷。我们的目标是构建类似于寄生虫细胞表面的完全合成的糖缀合物，并在小鼠免疫研究中对其进行测试。这项研究的结果可能会导致一种对公共卫生产生巨大影响的疫苗，不仅可以挽救中美洲数千人的生命，还可以保护美国面临风险的个人。