INHERITED CONTROL MECHANISMS IN IG GENE EXPRESSION

IG 基因表达的遗传控制机制

• 批准号: 2060854
• 负责人: ELIZABETH K BIKOFF
• 金额: $ 23.87万
• 依托单位: HARVARD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1981
• 资助国家: 美国
• 起止时间: 1981-09-01 至 1998-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2060854
• 关键词: MHC class II antigen; antigen presenting cell; cell differentiation; dendritic cells; gene expression; genetic strain; genetically modified animals; immunogenetics; immunoglobulin G; immunoglobulin genes; immunoregulation; interleukin 4; laboratory mouse; leukocyte activation /transformation; lipopolysaccharides; macrophage

The long-term goal of this research is to better understand MHC class II-restricted antigen presentation. Class II a/beta heterodimers associate intracellularly with a third polypeptide chain, the invariant chain, that affects class II maturation. A significant contribution by this lab during the past period of support was the generation of a novel mouse strain carrying a targeted mutation at the invariant chain locus and the description of its striking phenotype. Experiments proposed in this application aim to further analyze the ability of invariant chain to affect the structure of MHC class II molecules on the surface of diverse antigen-presenting cells in the intact animal. We plan to compare the invariant chain dependency of class II molecules produced in different MHC backgrounds and to evaluate possible effect(s) of IL4/LPS stimulation on class II maturation. We will also examine biosynthesis and maturation of class II molecules expressed by dendritic cells, activated macrophages, and thymic stromal cells. A second goal is to further analyze the contribution of MHC-associated Ii chain to CD4+ T cell maturation. We plan to test the possibility that the few remaining CD4 T cells present in Ii mice may represent an intermediate, partially selected CD4 subset. We will examine their V/beta repertoire, and determine if these cells are triggered to proliferate and/or produce lymphokines in response to TCR crosslinking. Additionally, thymic organ cultures will be used to study defective CD4+ T cell maturation. We will seek evidence for positive selection by peptide and evaluate the V/beta repertoire of emerging CD4+ T cell clones. Finally, a major goal is to examine potentially divergent role(s) played by structurally distinct Ii31 and 41 proteins that arise as the result of alternative mRNA splicing. We plan to generate transgenic mouse strains that exclusively express the p31 or p41 form of invariant chain protein that also show an appropriate tissue-specific pattern of expression in vivo. These novel mouse strains will be used to analyze the capacity of invariant chain p31 and/or p41 alone to affect class II biochemistry, APC activity, and T cell selection in these strains. Overall, these experiments will hopefully provide further insight into functional role(s) played by the MHC class II-associated Ii chain in immune regulation.

这项研究的长期目标是更好地了解MHC课程 II限制的抗原表现。 II类A/Beta异二聚体 细胞内与第三多肽链（不变） 链，影响II类成熟。 一个重大贡献 在过去的支持期间，这个实验室是一代小说的一代 在不变链基因座处携带靶向突变的小鼠应变 以及其引人注目的表型的描述。 提出的实验 该应用程序旨在进一步分析不变链的能力 影响MHC II类分子的结构 完整动物中的多种抗原呈递细胞。 我们计划 比较在中产生的II类分子的不变链依赖性 不同的MHC背景并评估IL4/LP的可能效果 对II类成熟的刺激。 我们还将检查生物合成 和树突状细胞表达的II类分子的成熟， 活化的巨噬细胞和胸腺基质细胞。 第二个目标是 进一步分析MHC相关II链对CD4+ T的贡献 细胞成熟。 我们计划测试剩下的少数 II小鼠中存在的CD4 T细胞可能代表一个中间体 选定的CD4子集。 我们将检查他们的V/beta曲目，以及 确定是否触发这些细胞以增殖和/或产生 淋巴动物响应TCR交联。 另外，胸腺器官 培养物将用于研究缺陷的CD4+ T细胞成熟。 我们 将寻求通过肽进行积极选择的证据，并评估 v/beta曲目的新兴CD4+ T细胞克隆。 最后，一个主要目标 是检查结构上扮演的潜在分歧 由于替代而产生的独特的II31和41蛋白 mRNA剪接。 我们计划生成转基因小鼠菌株 专门表达不变链蛋白的p31或p41形式 还显示适当的组织特异性表达模式。 这些新型的小鼠菌株将用于分析 仅影响II类生物化学的不变链p31和/或p41， 这些菌株中的APC活性和T细胞选择。 总体而言，这些 实验希望能够进一步了解功能 MHC II类相关II链在免疫中扮演的角色 规定。