Mapping novel subdominant B*5701 epitopes in conserved regions of the HIV proteom

绘制 HIV 蛋白质组保守区域中新的亚显性 B*5701 表位图谱

• 批准号: 7554083
• 负责人: JUNE KAN-MITCHELL
• 金额: $ 57.13万
• 依托单位: UNIVERSITY OF TEXAS EL PASO
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7554083
• 关键词: Affect; Alleles; Antigens; Attenuated; Autologous Dendritic Cells; Avidity; Binding; Biological Assay; CD8B1 gene; Characteristics; Class; Clinic; Clinical; Complement; Correlative Study; Dendritic Cells; Disease Outcome; Entropy; Epitopes; Failure; Flow Cytometry; Future; Gagging; Genome; Gerda brand of difluprednate; Goals; HIV; Human; Immune response; In Vitro; Individual; Infection; Infection Control; Learning; Lentivirus Vector; Link; Longitudinal Studies; Maps; Measures; Modeling; Monitor; Numbers; Outcome; Patients; Pattern; Peptides; Population; Proteins; Proteome; Public Health; Quality Control; Relative (related person); Score; T-Lymphocyte; Time; Vaccination; Vaccine Design; Vaccines; Variant; Viral; Virus; base; cohort; cytokine; design; disorder control; gag-pol Fusion Proteins; immunogenic; improved; insight; mutant; novel; novel vaccines; pol genes; polypeptide; positional cloning; research clinical testing; response; success

DESCRIPTION (provided by applicant): A T cell-based vaccine to HIV with its highly variable genome is a formidable challenge, since it will have to protect against many viral variants. As a novel vaccine approach, we propose to focus the T cell immune response to four highly conserved regions of the HIV proteome, which may be invariant due to functional or structural constraints. This is a simple and testable vaccine approach designed to overcome HIV variability. The HLA-B*57 class I molecule (B*57) is linked with better disease outcome. Here we will characterize responses to our T cell vaccine components in B*57+ donors in a proof-of-principle study. Specific Aim 1 will map new B*57-restricted epitopes in the four highly conserved regions of the HIV proteome. Targeting several proteins (Gag, Pol and Env) should help reduce virus escape for long term control. Known dominant epitopes found in the Gag regions will be extinguished by reverse genetics. CD8+ T cells from healthy donors will be primed by autologous DCs transduced by lentiviral vectors to express these polypeptides. Optimal minimal epitopes will be mapped and binding to B*5701 verified. Specific Aim 2 will characterize the CD8+ T cells to selected epitopes generated by ex vivo priming from healthy donors. We will assess i) various in vitro CTL functions; ii) the ability of these responses, individually or in combination, to suppress the in vitro replication of wild type or attenuated variant NL4-3 viruses; and iii) the epitope-specific pre-vaccination TCR repertoire reserve. We will focus on shared (commonly recognized) epitopes and in particular, to those found linked to greater disease control in Specific Aim 3. Specific Aim 3 will seek responses to all novel epitopes in B*57+ patients, to determine whether any is linked to relative control of disease. They will be monitored ex vivo directly or after one re-stimulation with cognate epitopic peptides, to measure recall T cell responses. Their functional profiles will be further assessed by polychromatic flow cytometry and, if possible, compared to contemporaneous responses to other known B*57 responses within the same individuals. Longitudinal studies which are more informative than cross-sectional ones will also be performed to further elucidate promising responses. A secondary goal is to develop an ex vivo human model useful for advancing future vaccine candidates to clinical testing. In summary, this study should provide new insights into the characteristics of HIV-specific CD8+ T cells important for HIV control and the qualities that should be sought in vaccine-induced T cells as well as to determine whether the most conserved portions of HIV proteins are valuable vaccine candidates. PUBLIC HEALTH RELEVANCE A T cell-based vaccine to HIV with its highly variable genome is a formidable challenge, since it will have to protect against many viral variants. We propose a simple and testable vaccine approach designed to overcome HIV variability by focusing the T cell response to highly conserved regions of the HIV proteome. We expect to learn more about how responding T cells contribute to HIV control and will evaluate an ex vivo human vaccination model that may help advance future vaccine candidates to clinical testing.

描述（由申请人提供）：基于 T 细胞的 HIV 疫苗具有高度可变的基因组，这是一项艰巨的挑战，因为它必须防范许多病毒变体。作为一种新的疫苗方法，我们建议将 T 细胞免疫反应集中在 HIV 蛋白质组的四个高度保守的区域，这些区域可能由于功能或结构的限制而保持不变。这是一种简单且可测试的疫苗方法，旨在克服艾滋病毒的变异性。 HLA-B*57 I 类分子 (B*57) 与更好的疾病结果相关。在这里，我们将在原理验证研究中描述 B*57+ 捐赠者对我们的 T 细胞疫苗成分的反应。具体目标 1 将在 HIV 蛋白质组的四个高度保守区域绘制新的 B*57 限制性表位。针对多种蛋白质（Gag、Pol 和 Env）应有助于减少病毒逃逸，从而实现长期控制。在 Gag 区域发现的已知显性表位将通过反向遗传学消除。来自健康供体的 CD8+ T 细胞将由慢病毒载体转导的自体 DC 引发，以表达这些多肽。将绘制最佳最小表位并验证与 B*5701 的结合。具体目标 2 将表征 CD8+ T 细胞与健康供体体外引发产生的选定表位。我们将评估 i) 各种体外 CTL 功能； ii) 这些反应单独或组合抑制野生型或减毒变体NL4-3病毒体外复制的能力； iii) 表位特异性疫苗接种前 TCR 库储备。我们将重点关注共享（普遍认可）的表位，特别是那些在特定目标 3 中发现与更好的疾病控制相关的表位。特定目标 3 将寻求对 B*57+ 患者中所有新表位的反应，以确定是否有任何关联达到相对控制疾病的目的。将直接或在用同源表位肽进行一次再刺激后对它们进行离体监测，以测量回忆 T 细胞反应。他们的功能概况将通过多色流式细胞术进一步评估，如果可能的话，与同一个体内其他已知 B*57 反应的同期反应进行比较。还将进行比横断面研究提供更多信息的纵向研究，以进一步阐明有希望的反应。第二个目标是开发一种离体人体模型，有助于将未来的候选疫苗推进临床测试。总之，这项研究应该为 HIV 特异性 CD8+ T 细胞的特征提供新的见解，这些特征对于 HIV 控制很重要，并且应该在疫苗诱导的 T 细胞中寻求质量，并确定 HIV 蛋白中最保守的部分是否是有价值的候选疫苗。 公共卫生相关性 基于 T 细胞的 HIV 疫苗具有高度可变的基因组，这是一项艰巨的挑战，因为它必须防范许多病毒变体。我们提出了一种简单且可测试的疫苗方法，旨在通过将 T 细胞反应集中于 HIV 蛋白质组的高度保守区域来克服 HIV 变异性。我们希望更多地了解应答 T 细胞如何有助于 HIV 控制，并将评估离体人体疫苗接种模型，这可能有助于将未来的候选疫苗推向临床测试。