CD44: HYALURONIC ACID BINDING AND LYMPHOCYTE MIGRATION

CD44：透明质酸结合和淋巴细胞迁移

• 批准号: 2672083
• 负责人: ROBERT A HYMAN
• 金额: $ 36.97万
• 依托单位: SALK INSTITUTE FOR BIOLOGICAL STUDIES
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-05-01 至 2001-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2672083
• 关键词: CD44 molecule; T cell receptor; T lymphocyte; cell migration; chemical binding; extracellular matrix; flow cytometry; glycosylation; hyaluronate; laboratory mouse; tissue /cell culture; transfection

This is an application to study the biological function of the CD44 molecule of activated T lymphocytes, and to define the parameters that determine high affinity binding of this receptor to the extracellular matrix. Hyaluronan is a specific ligand of CD44 and although abundant very few T-cells bind to it despite expressing the receptor, albeit in an inactive form. The goal of this application is to identify the mechanism that conveys a low affinity (non-binding) CD44 molecule to a high affinity one. In cellular terms high affinity-binding appears to be a feature of activated T-cells, and it follows that the expression of this high affinity-receptor is a regulated event. The biological implications are directed migration in inflammation and metastasis. In more specific terms, one can distinguish between an inactive binding state, an inductive one and a constitutive one. The PI has succeeded in deriving mutant cell lines that represent these three phenotypes, allowing the detailed study proposed here of the molecular conditions governing the three binding states. An important lead has been the demonstration that distinct N-glycosylation patterns are correlated with presence or absence of hyaluronan binding. Using transfections with mutants of glycosylation sites it was shown that absence of carbohydrate on one site at position 25 confers constitutive hyaluronan binding activity on an otherwise inducible cell line. These experiments leave little doubt that N glycosylation implies the action of trans acting genes, and since results of a number of biological experiments, including somatic hybridization, also postulate the existence of 2 genes modulating the CD44 function, the search is on to identify these, A transfection strategy free of prejudice regarding the function of such genes is proposed for their isolation. Finally in the third aim, the immunological function of CD44 is approached by studying the role of CD44 in mediating lymphocyte trafficking.

这是一个研究 CD44 生物学功能的应用程序 激活的 T 淋巴细胞分子，并定义参数 确定该受体与细胞外的高亲和力结合 矩阵。 透明质酸是 CD44 的特异性配体，虽然含量丰富 尽管表达了受体，但很少有 T 细胞与其结合，尽管在 一种不活跃的形式。 该应用程序的目标是识别 将低亲和力（非结合）CD44 分子传递至 亲和力高的一位。 在细胞方面，高亲和力结合似乎 是激活的 T 细胞的一个特征，因此表达式 这种高亲和力受体的发生是一个受调控的事件。 生物的 影响是炎症和转移中的定向迁移。 在 更具体的术语，我们可以区分非活动绑定 状态，分为归纳状态和本构状态。 PI已成功 在衍生代表这三种表型的突变细胞系时， 允许此处提出的分子条件的详细研究 管理三个约束状态。 一个重要的线索是 证明不同的 N-糖基化模式与 透明质酸结合的存在或不存在。 使用转染 糖基化位点突变体表明，碳水化合物的缺失 在位置 25 的一个位点上赋予组成型透明质酸结合 对其他可诱导细胞系的活性。这些实验留下 毫无疑问，N 糖基化意味着反式作用的作用 基因，并且由于许多生物实验的结果， 包括体细胞杂交，还假设存在2个基因 调制 CD44 功能，搜索就可以识别这些，A 转染策略不影响此类功能 建议将基因用于分离。 最后，在第三个目标中， 通过研究 CD44 的作用来了解 CD44 的免疫功能 CD44 介导淋巴细胞运输。