Mimotope Conversion of HIV-1 Carbohydrate Antigens

HIV-1 碳水化合物抗原的模拟表位转化

• 批准号: 6450918
• 负责人: THOMAS KIEBER-EMMONS
• 金额: $ 25.21万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-04-01 至 2002-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6450918
• 关键词: AIDS vaccines; HIV envelope protein; HIV envelope protein gp120; HIV envelope protein gp160; HIV envelope protein gp41; antibody specificity; biomimetics; biotechnology; carbohydrates; computer simulation; cross immunity; dendritic cells; enzyme linked immunosorbent assay; genetic library; human immunodeficiency virus 1; humoral immunity; immunologic memory; interferon gamma; interleukin 10; interleukin 4; laboratory mouse; lactose; mannose; mucosal immunity; neutralizing antibody; peptide library; vaccine development

Carbohydrate antigens have been the basis for eliciting protective immune responses against many pathogens, yet this approach has not been adequately assessed in HIV research. Anti- carbohydrate antibodies may facilitate the inhibition of infected cell binding to dendritic cells on mucosa to thwart early infection. We have developed a program concerned with the inter- conversion of carbohydrate epitopes associated with HIV into a peptide based vaccine strategy to augment carbohydrate cross- reactive systemic and mucosal responses. In specific aim 1, we test the hypothesis that immunity induced by peptide mimeotopes of HIV-1 associated carbohydrate antigens differs qualitatively and quantitatively from the immunity induced by the carbohydrate antigen itself. Of interest is the evaluation of polyclonal responses in terms of i. kinetics of antibody induction; ii. Carbohydrate/gp120 reactive isotype profiles; and iii. Carbohydrate/gp120 reactive antibody affinity/avidity. Evaluation of serum binding to epitopes exposed on native forms of gp120 and gp160, and heterologous strains of monomeric gp120 and cell surface-expressed oligomeric gp120/gp41 are evaluated. In specific aim 2, we explore ways to enhance carbohydrate reactive titers and expand on the breadth of HIV immunoreactivity. Systemic and mucosal responses are evaluated following priming with mimetic or carbohydrate formulations and boosting with oligomeric-gp160 formulates. Serum and mucosal lavages are tested for i. Neutralization of Lab and primary isolates ii. Inhibition of Dendritic cell adherence and infection iii. Evaluation of serum antibody binding to gp120 epitopes as in aim 1 are also evaluated. In specific aim 3, systematic approaches involving molecular modeling and phage display libraries are used to analyze and exploit topological similarities to further define prototypic peptide mimeotope templates of HIV-1 associated carbohydrate antigens. In this aim, topological relationships between HIV-1 associated mannosyl and lactoseries carbohydrate structures are correlated with binding properties of peptide mimeotopes reactive with selected lectins and a highly effective carbohydrate reactive HIV-1 neutralizing antibody 2G12. We further define variants of peptides that display high affinity binding to these receptors by 1.) Synthesizing and biopanning defined peptide array libraries representative of secondary structure elements reflective of carbohydrate and peptide structures; and 2.)Evaluation of the affinity of ligand binding by Biacore and computer modeling studies.

碳水化合物抗原已成为引发针对许多病原体的保护性免疫反应的基础，但这种方法尚未在艾滋病毒研究中得到充分评估。抗碳水化合物抗体可能有助于抑制感染细胞与粘膜上树突状细胞的结合，从而阻止早期感染。我们开发了一个项目，将与HIV相关的碳水化合物表位相互转化为基于肽的疫苗策略，以增强碳水化合物交叉反应的全身和粘膜反应。在特定目的1中，我们验证了HIV-1相关碳水化合物抗原肽模位诱导的免疫在质量和数量上与碳水化合物抗原本身诱导的免疫不同的假设。我们感兴趣的是多克隆反应的评价：1 .抗体诱导动力学；2。碳水化合物/gp120反应性同型谱；ⅲ。糖类/gp120反应性抗体亲和力/亲和度。评估了暴露在天然形式gp120和gp160上的血清与表位的结合，以及单分子gp120和细胞表面表达的寡聚物gp120/gp41的异种菌株。在具体目标2中，我们探索了提高碳水化合物反应滴度和扩大HIV免疫反应性广度的方法。用模拟或碳水化合物配方和用低聚物-gp160配方增强后，评估系统和粘膜反应。对血清和粘膜灌洗进行测试，1 .实验室和原代分离物的中和作用2。树突状细胞粘附和感染的抑制iii。评估血清抗体结合gp120表位的目的1也进行了评估。在特定目标3中，采用包括分子建模和噬菌体展示文库在内的系统方法来分析和利用拓扑相似性，以进一步定义HIV-1相关碳水化合物抗原的原型肽模位模板。在本研究中，HIV-1相关甘露糖基和乳系列碳水化合物结构之间的拓扑关系与与选定凝集素和高效碳水化合物反应的HIV-1中和抗体2G12反应的肽咪桃位的结合特性相关。我们进一步定义了与这些受体显示高亲和力结合的肽变体。合成和生物筛选具有代表性的反映碳水化合物和肽结构的二级结构元件的定义肽阵列文库；和2)。用Biacore评估配体结合的亲和力和计算机建模研究。