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）：具有高度可变基因组的基于T细胞的疫苗是一个巨大的挑战，因为它必须保护许多病毒变异。作为一种新型的疫苗方法，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，这可能是由于功能或结构约束而不变的。这是一种旨在克服HIV变异性的简单且可检验的疫苗方法。 HLA-B*57 I类分子（B*57）与更好的疾病结局有关。在这里，我们将表征对原理证明研究中B*57+供体中对T细胞疫苗成分的反应。特定的目标1将在HIV蛋白质组的四个高度保守区域中绘制新的B*57限制表位。靶向多种蛋白质（GAG，POL和ENV）应有助于减少病毒逃生以进行长期控制。反向遗传学将熄灭在插科打区域中发现的已知主要表位。来自健康供体的CD8+ T细胞将由慢病毒载体转导的自体DC来表达这些多肽。最佳最小份量将被映射并结合到B*5701。特定的AIM 2将表征CD8+ T细胞是由健康供体的离体启动产生的选定表位。我们将评估I）各种体外CTL功能； ii）这些反应单独或组合的能力抑制野生型或衰减NL4-3病毒的体外复制的能力； iii）表位特异性预疫苗的TCR曲目储备。我们将重点关注共享的（常识）表位，尤其是在特定目标中与更大的疾病控制相关的发现。特定目标3将寻求对B*57+患者中所有新型表位的反应，以确定是否与疾病的相对控制有关。将它们直接或在用同源表肽重新刺激后直接监测它们，以测量回忆T细胞反应。与同时对同一个体中其他已知的B*57响应相比，将通过多色流式细胞仪进一步评估它们的功能曲线。还将进行比横截面的纵向研究，以进一步阐明有前途的反应。次要目标是开发一个实体人类模型，可用于将未来的候选疫苗推向临床测试。总而言之，这项研究应提供有关HIV特异性CD8+ T细胞对HIV控制重要的特征以及在疫苗诱导的T细胞中应寻求的品质的特征，以及确定HIV蛋白最保守的部分是否是有价值的疫苗候选者。 公共卫生相关性的基于T细胞的疫苗与HIV具有高度可变的基因组是一个巨大的挑战，因为它必须预防许多病毒型变异。我们提出了一种简单且可检验的疫苗方法，旨在通过将T细胞反应聚焦于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响应T细胞如何对HIV控制做出贡献，并将评估一个离体人类疫苗接种模型，该模型可能有助于将未来的候选候选物推向临床测试。