Genetic and Biochemical Approaches to Tyrosine Kinase Fu

酪氨酸激酶 Fu 的遗传和生化方法

• 批准号: 6555995
• 负责人: PAMELA SCHWARTZBERG
• 金额: --
• 依托单位: NATIONAL HUMAN GENOME RESEARCH INSTITUTE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6555995
• 关键词: B lymphocyte; T cell receptor; T lymphocyte; antigen antibody reaction; biological signal transduction; cell differentiation; cell proliferation; cellular immunity; enzyme activity; gene mutation; genetically modified animals; helper T lymphocyte; hypogammaglobulinemia; immune system; immunogenetics; interferon gamma; interleukin 4; laboratory mouse; leukocyte activation /transformation; phenotype; phosphorylation; protein structure function; protein tyrosine kinase; skeletal system; tissue /cell culture; transcription factor

Our laboratory studies signal transduction involving tyrosine phosphorylation and non-receptor tyrosine kinases, molecules required for intracellular signaling pathways involved in normal cellular growth and differentiation as well as the abnormal growth and development involved in the formation and progression of cancer. Using a combination of mouse genetics, cell biology and protein biochemistry, our work has concentrated on how these molecules contribute to normal function of cells of the immune system and the skeletal system. Through these studies we hope to understand how manipulation of these pathways can be utlilized to develop therapeutics for diseases affecting these systems. In recent years our work has concentrated on studies of the Tec family of tyrosine kinases, the prototypical member of which, Btk, is required for normal function of B cells. Mutation of Btk is responsible for the human genetic disorder X-linked agammmaglobulimemia. We have previously shown that mutation of Tec family kinases expressed in T cells can severely impair T lymphocyte function in mice, thereby establishing for the first time a role for these kinases in T cell mediated immune responses. In the last year our work has concentrated on how these kinases participate in the signaling pathways involved in T helper cell differentiation, a critical regulatory component of immune responses that helps determine whether an individual mounts a cellular (Th1) or antibody based, (Th2) immune response. We have found that mutation of Tec kinases can alter activation and repression of transcription factors involved in Th2 CD4+ T helper cell differentiation. Our results suggest that impairment of TCR responses may not only reduce the ability of an animal to respond to antigen, but may also alter the type of immune response generated. As an extension of these studies, we began examining other signaling molecules potentially involved in T helper cell differentiation including SAP, which is mutated in the genetic disorder X-linked proliferative syndrome (XLP). In this last year we have generated mice deficient in SAP. SAP-deficient mice had normal lymphocyte development, but upon challenge with infectious agents, recapitulated features of XLP, including increased T cell activation and IFN-g production, and decreased antibody production. Splenocytes from uninfected SAP- mice produced increased IFN-g and decreased IL-4, suggesting a skewing of these animals to a Th1 phenotype. Our results suggest that T helper cell misregulation may contribute to phenotypes associated with (XLP).

我们的实验室研究涉及酪氨酸磷酸化和非受体酪氨酸激酶的信号转导，这些分子是参与正常细胞生长和分化以及参与癌症形成和进展的异常生长和发育的细胞内信号传导途径所需的分子。我们结合小鼠遗传学、细胞生物学和蛋白质生物化学，研究这些分子如何促进免疫系统和骨骼系统细胞的正常功能。通过这些研究，我们希望了解如何利用这些途径的操纵来开发针对影响这些系统的疾病的疗法。近年来，我们的工作集中在酪氨酸激酶 Tec 家族的研究上，其中的典型成员 Btk 是 B 细胞正常功能所必需的。 Btk 突变是导致人类遗传性疾病 X 连锁无球蛋白血症的原因。我们之前已经证明，T 细胞中表达的 Tec 家族激酶的突变会严重损害小鼠的 T 淋巴细胞功能，从而首次确定了这些激酶在 T 细胞介导的免疫反应中的作用。去年，我们的工作重点是这些激酶如何参与 T 辅助细胞分化的信号通路，T 辅助细胞分化是免疫反应的关键调节成分，有助于确定个体是否产生基于细胞 (Th1) 或抗体的 (Th2) 免疫反应。我们发现 Tec 激酶的突变可以改变参与 Th2 CD4+ T 辅助细胞分化的转录因子的激活和抑制。我们的结果表明，TCR 反应受损不仅可能降低动物对抗原反应的能力，还可能改变产生的免疫反应的类型。作为这些研究的延伸，我们开始研究可能参与 T 辅助细胞分化的其他信号分子，包括 SAP，它在遗传性疾病 X 连锁增殖综合征 (XLP) 中发生突变。去年，我们培育出了缺乏 SAP 的小鼠。 SAP 缺陷小鼠的淋巴细胞发育正常，但在受到感染原的攻击后，会重现 XLP 的特征，包括 T 细胞活化和 IFN-g 产生增加，以及抗体产生减少。未感染 SAP 小鼠的脾细胞产生的 IFN-g 增加，IL-4 减少，表明这些动物倾向于 Th1 表型。我们的结果表明，T 辅助细胞的失调可能导致与 (XLP) 相关的表型。