Involvement of Nonclassical MHC in Early T Cell Ontogeny in Xenopus

非经典 MHC 参与非洲爪蟾早期 T 细胞个体发育

• 批准号: 7915338
• 负责人: JACQUES Robert
• 金额: $ 7.66万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-15 至 2011-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7915338
• 关键词: Accounting; Adopted; Adult; Amphibia; Antibodies; Biological; Biological Metamorphosis; Bypass; CD8B1 gene; Cell Lineage; Cell Maturation; Cell surface; Cells; Communities; Complex; Dependence; Dependency; Development; Education; Embryo; Epithelial; Flow Cytometry; Future; Gene Transfer Techniques; Generations; Genes; Gills; Goals; Growth; Hybridomas; Immune; Immune system; Immunity; Immunization; Immunocompetent; Immunology; In Situ Hybridization; J segment gene; Jaw; Larva; Life; Ligands; Liver; Lymphocyte; Mature T-Lymphocyte; Mediating; Messenger RNA; Modeling; Molecular Profiling; Mus; Pathway interactions; Pattern; Peptides; Peripheral; Phage Display; Phylogenetic Analysis; Physiological; Play; Process; Proteins; Protocols documentation; RNA Interference; Rana; Reagent; Recombinants; Regulation; Relative (related person); Research Personnel; Role; Signal Transduction; Spleen; Staging; Surface; T cell differentiation; T-Cell Development; T-Cell Receptor; T-Lymphocyte; TCF Transcription Factor; Technology; Testing; Thymus Gland; Vertebrates; Work; Xenopus; Xenopus laevis; base; comparative; genome sequencing; improved; in vivo; insight; neonate; novel; pathogen; public health relevance; receptor; response; technology development; thymocyte; transcription factor; tumor; xenopus development

DESCRIPTION (Provided by Applicant): The overall goal of this application is to explore the involvement of non-classical MHC class Ib (class Ib) molecules in thymocyte differentiation during early development by a comparative approach in the Xenopus. Increasing evidence suggests that in the absence or suboptimal expression of 'classical' MHC class Ia (class Ia) as it occurs in neonates, class Ib molecules can generate survival signals to differentiating thymocytes. Not much is known about the physiological relevance of this alternative thymic selection process. It is hypothesized that in the absence (or suboptimal level) of class Ia expression early in development, thymic differentiation and T cell education critically depends on class Ib. Both the thymic dependence of T cells and the factors that play key roles in the regulation of T cell development are broadly conserved among jawed vertebrates. Therefore, the investigators propose to use the Xenopus and its immunocompetent but naturally class Ia-deficient larval stage as a model because it provides the advantage of having the early developing thymus of larvae externally visible, easily accessible, and amenable to experimental manipulation. Importantly, the hypothesis involving class Ib can be tested in the natural absence of class Ia, and the development of T cells can be studied in a biological context. Finally, the investigators have recently characterized a novel Xenopus nonclassical MHC class Ib (XNC) gene subfamily, XNC10, whose expression is tightly associated with the CD8 T-cell lineage during thymocyte differentiation since early in ontogeny. Therefore, they propose to test the hypothesis that class Ib genes are critically involved in thymic differentiation and T cell education during ontogeny of Xenopus. This will be achieved by the two following aims: 1. To determine the expression pattern of XNC10 and a selected set of immune genes during ontogeny: This will involve in situ hybridization as well as immunohistology and flow cytometry analysis for which they will generate new antibodies against XNC10 and other thymocytes markers (e.g., CD4, CD8¿, TCR¿, a); and 2. To assess the function of XNC10 in T cell differentiation and thymic education, which will involve in vivo knockdown by RNA interference using transgenesis to reveal the function of XNC10 in CD8 T cell development. This application will provide fundamental, and not phylogenetically restricted, insight on the relative contributions of class Ia versus class Ib-mediated thymocyte education pathways during ontogeny. Technologies developed and reagents obtained will be of high benefit for the scientific community and will considerably increase the potential of X. laevis as a non-mammalian alternative model. PUBLIC HEALTH RELEVANCE: The goal of this project is to better understand the possible role of certain MHC nonclassical class I molecules in assisting the development of fully mature T cells during early stage of life and ultimately helping their response against pathogens or tumors prone to escape the host's immune defenses. For this, the investigators will use an evolutionary approach that takes advantage of the frog X. laevis, which is a unique non-mammalian comparative model that permits easy access of the thymus early during development.

描述（由申请人提供）：本申请的总体目标是探索非古典MHC类IB（IB类）分子在早期开发过程中通过Xenopus的比较方法在早期开发过程中的参与。越来越多的证据表明，在不存在或次优的表达中，“经典” MHC类IA（IA类）发生在新生儿中，IB类分子可以产生生存信号来区分胸腺细胞。关于这种替代性胸腺选择过程的物理相关性知之甚少。假设在发育早期IA表达的不存在（或次优水平），胸腺分化和T细胞教育严重取决于IB类。 T细胞的胸腺依赖性和在T细胞发育调节中起关键作用的因素在颌脊椎动物中都广泛保守。因此，研究人员建议使用爪蟾及其免疫能力但自然的IA缺陷幼虫阶段作为模型，因为它提供了具有早期发展幼虫外部可见幼虫的优势，易于访问，易于访问，并且可以通过实验性操纵。重要的是，涉及IB类的假设可以在自然缺乏IA类的情况下进行测试，并且可以在生物学环境中研究T细胞的发展。最后，研究人员最近表征了一种新型的Xenopus非经典MHC类IB（XNC）基因亚科XNC10，其表达与胸腺细胞分化的CD8 T细胞谱系紧密相关，因为胸腺细胞分化。因此，他们建议检验以下假设：IB类基因在Xenopus的个体发育过程中与胸腺分化和T细胞教育有关。这将通过以下两个目的来实现：1。确定个体发育过程中XNC10的表达模式和一组选定的免疫原子：这将涉及原位杂交以及免疫组织学和流式细胞仪分析，它们将对它们产生针对XNC10和其他胸腺细胞标记的新抗体（例如2。评估XNC10在T细胞分化和胸腺教育中的功能，这将涉及使用翻译的RNA干扰在体内敲低的敲低，以揭示XNC10在CD8 T细胞开发中的功能。 该应用将提供对本体发育过程中IA与IB级介导的胸腺细胞教育途径相对贡献的基本且不限制系统发育的洞察力。开发的技术和获得的试剂将对科学界带来很大的好处，并将大大提高X. laevis作为非哺乳动物替代模型的潜力。 公共卫生相关性：该项目的目的是更好地了解某些MHC非经典I类分子在生命早期阶段有助于完全成熟T细胞发展的可能作用，并最终帮助他们对病原体或肿瘤的反应，以逃避宿主的免疫防御能力。为此，研究人员将使用一种进化方法，该方法利用青蛙X. laevis，这是一个独特的非哺乳动物比较模型，可以在开发过程中轻松获取胸腺。