HCMV-Specific Cell-Mediated Immunity in Infants/Children

婴儿/儿童中 HCMV 特异性细胞介导的免疫

• 批准号: 6576776
• 负责人: Katherine F Luzuriaga
• 金额: $ 30.87万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-02-01 至 2006-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6576776
• 关键词: MHC class I antigen; cell line; cellular immunity; chemokine; child (0-11); children; clinical research; cytokine; cytomegalovirus; cytotoxic T lymphocyte; enzyme linked immunosorbent assay; flow cytometry; helper T lymphocyte; high performance liquid chromatography; host organism interaction; human immunodeficiency virus 1; human tissue; immunofluorescence technique; infant human (0-1 year); phenotype; polymerase chain reaction; tissue /cell culture; virus load; virus protein

DESCRIPTION (provided by applicant): Cytomegalovirus (HCMV) is the most common human congenital infection worldwide and frequently causes multi-organ disease in immunocompromised hosts. In adults, the importance of HCMV-specific cell-mediated immune responses has been established for control of HCMV viremia and protection against disease development. However, the capability of young human infants to generate virus-specific cell-mediated immunity has not been well defined. We therefore propose to study the development of HCMV-specific:CD4+ and CD8+ T lymphocyte responses in infants experiencing primary infection. We hypothesize that virus-specific T lymphocyte responses will demonstrate qualitative and quantitative changes over time following primary infection. To address this hypothesis, we will characterize the magnitude and breadth of HCMV-specific CD8+ T cell responses in infants and children from acute through chronic infection. We will first use ELISPOT assays to identify the hierarchy of recognition of HCMV proteins. Epitopes within the most commonly recognized HCMV proteins and their HLA Class I-restricting elements will be defined. Tetramers representing commonly recognized epitopes will be made and used to characterize changes in HCMV epitope-specific CD8+ T cell frequencies over time. We will then characterize the cell surface phenotypes cellular turnover, and activation state of HCMV epitope-specific T cells using tetramer-staining, along with monoclonal antibodies to cell-surface antigens; functional properties (lytic function, chemokine/cytokine secretion) of HCMV epitope-specific CD8+ T cells will be evaluated. The frequencies and specificities of HCMV-specific CD4+ T cells will also be examined over time and correlated with HCMV-specific CD8+ T cell frequencies. Concurrent measurement of blood HCMV load will allow us to examine the relationship between HCMV-specific cell-mediated immune responses and blood HCMV load. Data from these studies will contribute to our understanding of age-related susceptibility to viral infections and will complement ongoing NIH-funded projects in our laboratory focused on examining the ability of young human infants to generate HIV-1 specific cell-mediated immune responses. The characterization of HCMV-specific cell-mediated immune responses and HCMV viral load over time following infection should help us to better understand virus-host interactions that contribute to the establishment of persistent viral infections and should aid in the development of improved prophylactic and therapeutic interventions for pediatric HCMV infection.

描述（由申请人提供）：巨细胞病毒（HCMV）是全球最常见的人类先天性感染，并且经常在免疫功能低下的宿主中引起多器官疾病。在成年人中，已经建立了HCMV特异性细胞介导的免疫反应的重要性，以控制HCMV病毒血症并防止疾病发育。但是，年轻人婴儿产生病毒特异性细胞介导的免疫的能力尚未得到很好的定义。因此，我们建议研究HCMV特异性的发展：患有原发性感染的婴儿的CD4+和CD8+ T淋巴细胞反应。我们假设病毒特异性的T淋巴细胞反应将表现出原发性感染后随时间的定性和定量变化。为了解决这一假设，我们将表征婴儿和从急性到慢性感染的婴儿和儿童中HCMV特异性CD8+ T细胞反应的大小和广度。我们将首先使用ELISPOT分析来识别HCMV蛋白识别的层次结构。将定义最常见的HCMV蛋白及其HLA I类限制元素的表位。代表普遍识别表位的四聚体将被制作并用于表征HCMV表位特异性CD8+ T细胞频率的变化。然后，我们将使用四聚体染色以及对细胞表面抗原的单克隆抗体以及单克隆抗体的细胞表面表型细胞表型和HCMV表位特异性T细胞的激活状态。将评估HCMV表位特异性CD8+ T细胞的功能特性（裂解功能，趋化因子/细胞因子分泌）。 HCMV特异性CD4+ T细胞的频率和特异性也将随着时间的流逝而进行检查，并与HCMV特异性CD8+ T细胞频率相关。同时测量血液HCMV负载将使我们能够检查HCMV特异性细胞介导的免疫反应与血液HCMV负载之间的关系。这些研究的数据将有助于我们理解与年龄相关的病毒感染易感性，并将补充我们实验室中正在进行的NIH资助的项目，专注于研究年轻人婴儿产生HIV-1特定细胞介导的免疫反应的能力。 HCMV特异性细胞介导的免疫反应和感染后随着时间的流逝的HCMV病毒负荷的表征应有助于我们更好地理解病毒宿主相互作用，这有助于建立持续性病毒感染，并应有助于改善预防性和治疗性HCMV感染的预防性和治疗性干预措施。