HIV Epitope Specific T Cell Responses and Control of HIV Replication

HIV 表位特异性 T 细胞反应和 HIV 复制的控制

基本信息

批准号：
7282098
负责人：
MARK A JACOBSON
金额：
$ 23.09万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-05-15 至 2009-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7282098
关键词：
Accounting Affect Antigens Autologous Biological Assay Blood CD3 Antigens CD4 Positive T Lymphocytes CD8-Positive T-Lymphocytes CD8B1 gene Cell Count Cell Degranulation Cell physiology Cells Characteristics Chronic Class Clinical Trials Dendritic Cells Development Disease Effector Cell Epitopes Failure Flow Cytometry Frequencies Future Gagging HIV HIV Infections HIV vaccine Haplotypes Immune Immune response Individual Infection Infection prevention Interferon Type II Interferons Interleukin-2 Investigation Measurement Measures Monitor Mutation Myelogenous Natural Killer Cells Numbers Observational Study Patients Pattern Peptides Peripheral Blood Mononuclear Cell Phenotype Plasma Proliferating Proteins Role Sampling Scanning Specimen T-Cell Proliferation T-Lymphocyte T-Lymphocyte Subsets TNF gene Testing Time Work cytokine experience immune function improved insight interest perforin response

项目摘要

DESCRIPTION (provided by applicant): A major obstacle to the development of an effective HIV vaccine is our lack of understanding of the critical components that constitute a protective, HIV-specific immune response. The aim of this proposal is to investigate, more comprehensively than has been done to date, the potential immunoprotective roles of a broad spectrum of different HIV epitope-specific T cell functions in controlling HIV replication among untreated patients with early HIV infection. The epitope-specific T cell functions that will be measured include CD4+ and CD8+ T cell IFN-g, TNF-a and IL-2 responses (and the maturational state of these responding cells), CD4+ and CD8+ T cell proliferation and CD8+ T cell perforin degranulation. All these functions can be measured by multiparameter flow cytometry after stimulation of PMBC with overlapping peptides that span relevant HIV antigenic proteins. We propose to begin this work by focusing on HIV Gag and Nef epitopes. However, since the measurement of all these T cell responses just these epitopes would require prohibitively large quantities of blood, we will focus on peptide motifs within an individual's autologous Gag/Nef sequence that are known to be HLA-restricted for that individual's haplotype. After sequencing autologous Gag and Nef sequences from stored plasma samples obtained just before untreated patients with early HIV infection established good control of HIV replication, and then again from subsequent timepoints when these same patients have lost that control, we will scan the sequences for HLA haplotype-appropriate motifs and then synthesize them as 9- and 15-mer peptides for Class I and II stimulation, respectively. These peptides will then be used in flow cytometry assays to identify autologous Gag/Nef epitope-specific CD4+ and CD8+ T cell proliferation and IFN-g, TNF-a and IL- 2 responses (and the maturational state of the cytokine-positive cells) and CD8+ T cell perforin degranulation responses. To control for changes in innate immune responses that could also affect control of HIV replication, we will also measure NK cells and function, plasmacytoid and myeloid dendritic cells and regulatory T cells in the same PBMC specimens. Understanding this pattern for clinically important, conserved HIV proteins such as Gag and Nef should improve understanding of the critical components of a protective, HIV-specific immune response and provide insight into the type of HIV epitope-specific T cell responses that may be useful to monitor in future trials of candidate HIV vaccines.

描述（由申请人提供）：开发有效的 HIV 疫苗的一个主要障碍是我们对构成保护性 HIV 特异性免疫反应的关键成分缺乏了解。该提案的目的是比迄今为止更全面地研究多种不同的 HIV 表位特异性 T 细胞功能在控制未经治疗的早期 HIV 感染患者中的 HIV 复制方面的潜在免疫保护作用。将测量的表位特异性 T 细胞功能包括 CD4+ 和 CD8+ T 细胞 IFN-g、TNF-a 和 IL-2 反应（以及这些反应细胞的成熟状态）、CD4+ 和 CD8+ T 细胞增殖以及 CD8+ T 细胞穿孔素脱颗粒。在用跨越相关 HIV 抗原蛋白的重叠肽刺激 PMBC 后，所有这些功能都可以通过多参数流式细胞术进行测量。我们建议通过关注 HIV Gag 和 Nef 表位来开始这项工作。然而，由于仅测量这些表位的所有这些 T 细胞反应就需要大量的血液，因此我们将重点关注个体自体 Gag/Nef 序列内的肽基序，已知这些基序对该个体的单倍型而言是 HLA 限制的。在对未经治疗的早期 HIV 感染患者建立对 HIV 复制的良好控制之前获得的储存血浆样本进行自体 Gag 和 Nef 序列测序后，然后在这些患者失去这种控制的后续时间点再次扫描 HLA 单倍型序列-适当的基序，然后将它们合成为 9 聚体和 15 聚体肽，分别用于 I 类和 II 类刺激。然后，这些肽将用于流式细胞术测定，以鉴定自体 Gag/Nef 表位特异性 CD4+ 和 CD8+ T 细胞增殖以及 IFN-g、TNF-a 和 IL-2 反应（以及细胞因子阳性细胞的成熟状态）和 CD8+ T 细胞穿孔素脱颗粒反应。为了控制也可能影响 HIV 复制控制的先天免疫反应的变化，我们还将测量同一 PBMC 标本中的 NK 细胞和功能、浆细胞样和髓样树突状细胞以及调节性 T 细胞。了解临床上重要的保守 HIV 蛋白（例如 Gag 和 Nef）的这种模式，应该可以提高对保护性 HIV 特异性免疫反应的关键组成部分的理解，并深入了解 HIV 表位特异性 T 细胞反应的类型，这可能有助于监测候选艾滋病毒疫苗的未来试验。