INHERITED CONTROL MECHANISIMS IN IG GENE EXPRESSION

这项研究的长期目标是更好地了解MHC类 II限制性抗原呈递。 II类α/β异二聚体 在细胞内与第三条多肽链，即不变的 链，影响II类成熟。 作出的重大贡献 这个实验室在过去的一段时间里的支持是一个小说的一代， 在不变链基因座携带靶向突变的小鼠品系 以及对它引人注目的表型的描述。 建议的实验 本应用旨在进一步分析不变链的能力 来影响细胞表面MHCII类分子的结构， 完整动物体内的多种抗原呈递细胞。 我们计划 比较产生的II类分子的不变链依赖性， 不同的MHC背景，并评估IL 4/LPS的可能作用 刺激II类成熟。 我们还将研究生物合成 以及树突细胞表达的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相关的Ii链对CD 4 + T细胞的贡献， 细胞成熟 我们计划测试剩下的几个 Ii小鼠中存在的CD 4 T细胞可能代表一种中间体，部分 选择的CD 4亚群。 我们将研究他们的V/beta曲目， 确定这些细胞是否被触发增殖和/或产生 淋巴因子对TCR交联的反应。 此外，胸腺器官 培养物将用于研究缺陷性CD 4 + T细胞成熟。 我们 将寻找肽的阳性选择的证据，并评估 新出现的CD 4 + T细胞克隆的V/β库。 最后，一个主要目标 是研究结构上可能不同的作用， 不同的Ii 31和41蛋白质，作为替代的结果出现， mRNA剪接。 我们计划培育转基因小鼠品系， 仅表达p31或p41形式的不变链蛋白， 也显示出适当的组织特异性体内表达模式。 这些新的小鼠品系将用于分析 不变链p31和/或p41单独影响II类生物化学， APC活性和T细胞选择。 总体而言，这些 实验将有望提供进一步的了解功能 MHC II类相关Ii链在免疫中的作用 调控

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.