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.

摘要 在过去的二十年里，我们开发梅毒疫苗的努力已经使我们能够识别出两种 在免疫/挑战实验中对梅毒给予高度但不完全保护的抗原 兔子模型。这两种候选疫苗来源于选定成员的保守区。 梅毒螺旋体重复序列(Tpr)抗原TprC/D2和TprK。对这些抗原的免疫力一直是 通过吞噬细胞增强病原体的清除，并提供实质性的保护 与对照相比，挑战地点的下巴发展情况。然而，在这些早期的疫苗设计中， 几个预测的TprC和TprD2蛋白的表面表位被省略，因为它们显示了一个 有限程度的抗原变异，即使我们证明了它们可以提供额外的 活化巨噬细胞对病原体调理和吞噬作用的靶点 佐剂诱导Th1型反应。 为了获得完全保护梅毒的疫苗，我们的目标是修改我们的早期疫苗设计，以包括额外的 TprC和TprD2蛋白的保护性表位。首先(目标1)，我们将评估其保护活性。 全长重组TprC和TprD2，使用覆盖所有抗原变体的抗原鸡尾酒 这些蛋白中也将包含TprK保守片段。同时，我们将开展一系列 绘制TprC和TprD2的T细胞表位和保护性B细胞表位的实验 开发抗原递送的替代平台，目标是递送选定的表位 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 对照抗原，因为这种蛋白的B细胞和T细胞表位在过去已经被确定。代替 重组蛋白，我们将设计和测试嵌合串联蛋白(AIM 2)和基于嵌合HPV的 病毒样颗粒(VLP，目标3)。这些替代的递送平台将特别诱导免疫力 梅毒螺旋体表面调理抗体的靶点，并可能增强病原体的清除 具有感染力的挑战。在目标4中，我们将结合我们的结果和卡梅伦博士获得的结果(项目1) 与她选择的候选疫苗(Tp0751)结合我们最具保护性的疫苗设计和交付 站台。随后，我们的FIRA疫苗设计的最终免疫/挑战实验将是 使用现代梅毒分离株评估整体保护水平和免疫持久性 在兔子免疫后挑战免疫动物。