Novel antigen designs and delivery platforms to enhance the protective ability of Tpr-based vaccines for syphilis

新型抗原设计和递送平台可增强基于 Tpr 的梅毒疫苗的保护能力

• 批准号: 10461740
• 负责人: Lorenzo Giacani
• 金额: $ 52.2万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10461740
• 关键词: Adjuvant; Animals; Antibodies; Antigenic Variation; Antigens; Appearance; Attenuated; B-Lymphocyte Epitopes; B-Lymphocytes; Biological Assay; Cell Separation; Cells; Delayed Hypersensitivity; Development; Disease; Engineering; Enzyme-Linked Immunosorbent Assay; Epidemiology; Epitope Mapping; Epitopes; Equipment and supply inventories; Family; Frequencies; Genome; Genomics; Goals; Human Papillomavirus; Human papillomavirus 16; Immunity; Immunization; Immunize; Infection; Knowledge; Length; Lesion; Maps; Measures; Modeling; Modernization; Monoclonal Antibodies; N-terminal; Oryctolagus cuniculus; Patients; Peripheral Blood Mononuclear Cell; Phagocytosis; Production; Proteins; Recombinant Proteins; Recombinants; Research; Series; Sexually Transmitted Diseases; Site; Surface; Syphilis; Syphilitic chancre; System; T-Lymphocyte Epitopes; Testing; Time; Treponema pallidum; Ulcer; Universities; Vaccine Design; Vaccines; Variant; Viral; Virulence Factors; Washington; aluminum sulfate; base; cytokine; design; experimental study; healing; immune clearance; lymphocyte proliferation; macrophage; member; novel; particle; pathogen; preservation; response; synthetic peptide; syphilis vaccine; vaccine candidate; vaccine delivery

ABSTRACT Over the last two decades, our efforts to develop a syphilis vaccine have allowed identification of two antigens that confer high but not complete protection to syphilis in immunization/challenge experiments in the rabbit model. These two vaccine candidates were derived from conserved regions of selected members of the Treponema pallidum repeat (Tpr) antigens TprC/D2 and TprK. Immunity to these antigens has been shown to enhance pathogen clearance by opsonophagocytosis and provide substantial protection from chancre development at challenge sites compared to controls. In these early vaccine designs, however, several predicted surface epitopes of the TprC and TprD2 proteins were omitted because they showed a limited degree of antigenic variation, even though we demonstrated that they could provide additional targets for pathogen opsonization and phagocytosis by activated macrophages if used in combination with adjuvants inducing a Th1-type response. To attain a fully protective syphilis vaccine we aim to modify our early vaccine design to include additional protective epitopes of the TprC and TprD2 proteins. First (Aim 1), we will evaluate the protective activity of full-length recombinant TprC and TprD2 using a cocktail of antigens designed to cover all antigenic variants of these proteins, which will also contain the TprK conserved fragment. In parallel, we will conduct a series of experiments to map T-cell epitopes and protective B-cell epitopes of TprC and TprD2 to inform development of alternative platforms for antigen delivery, with the goal of delivering selected epitopes rather than on full length antigens. For these mapping experiments (also planned in Aim 1), we will use TprK as a control antigen, as B-and T-cell epitopes were already identified for this protein in the past. In lieu of recombinant proteins, we will engineer and test chimeric concatemers (Aim 2) and chimeric HPV-based viral-like particles (VLPs, Aim 3). These alternative delivery platforms will specifically induce immunity to targets of opsonizing antibodies on the treponemal surface, and likely enhance pathogen clearance upon infectious challenge. In Aim 4, we will combine our results and those obtained by Dr. Cameron (Project 1) with her selected vaccine candidate (Tp0751) to combine our most protective vaccine designs and delivery platform. Subsequently, a final immunization/challenge experiment with our fila vaccine design will be performed to assess overall level of protection and durability of immunity using a modern syphilis isolate to challenge immunized animals following rabbit immunization.

抽象的 在过去的二十年中，我们开发梅毒疫苗的努力允许确定两种 在免疫/挑战实验中赋予梅毒的抗原，但不能完全保护梅毒 兔子模型。这两个候选疫苗源自选定成员的保守区域 Treponema Pallidum重复（TPR）抗原TPRC/D2和TPRK这些抗原的免疫力已经 证明可以通过调查性胞毒细胞增强病原体清除，并提供了实质性的保护 与对照组相比，挑战地点的临时开发。但是，在这些早期的疫苗设计中， 省略了TPRC和TPRD2蛋白的几个预测的表面表位，因为它们显示出 抗原变异程度有限，即使我们证明它们可以提供额外 如果与 诱导Th1型反应的佐剂。 为了获得完全保护性的梅毒疫苗，我们旨在修改我们的早期疫苗设计，以包括其他 TPRC和TPRD2蛋白的保护性表位。首先（AIM 1），我们将评估 全长重组TPRC和TPRD2，使用旨在覆盖所有抗原变异的抗原鸡尾酒 这些蛋白质也将包含TPRK保守的片段。同时，我们将进行一系列 映射T-Cell表位和TPRC和TPRD2的保护性B细胞表位的实验 开发用于抗原交付的替代平台，目的是提供所选的表位 而不是全长抗原。对于这些映射实验（也计划在AIM 1中），我们将使用TPRK作为一个 对照抗原，过去已经确定了该蛋白质的B和T细胞表位。代替 重组蛋白，我们将设计和测试嵌合助剂（AIM 2）和基于嵌合HPV 病毒样颗粒（VLP，AIM 3）。这些替代交付平台将特别引起免疫力 在三链球间表面上调整抗体的靶标，并可能增强病原体清除率 传染性挑战。在AIM 4中，我们将结合我们的结果以及卡梅伦博士（项目1）获得的结果 与她选定的疫苗候选者（TP0751）一起结合了我们最保护性疫苗的设计和输送 平台。随后，我们的FILA疫苗设计将进行最终的免疫/挑战实验 通过现代的梅毒分离物评估总体保护和免疫力的总体保护水平 挑战兔子免疫后免疫动物。