New signaling pathways that positively and negatively regulate CD4 T cells via th

新的信号通路通过 th 正向和负向调节 CD4 T 细胞

基本信息

批准号：
7894642
负责人：
EDWARD Y SKOLNIK
金额：
$ 4.2万
依托单位：
NEW YORK UNIVERSITY SCHOOL OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2008
资助国家：
美国
起止时间：
2008-07-01 至 2013-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7894642
关键词：
1-Phosphatidylinositol 3-Kinase Antigen-Presenting Cells Antigens Autoimmune Diseases Binding Biological CD4 Positive T Lymphocytes Calcium-Activated Potassium Channel Cellular biology Data Development Diphosphates Disease Drug Delivery Systems Feedback Goals Graft Rejection Histidine Human In Vitro Learning Lipid Bilayers Location Mediating NME1 gene Nucleoside diphosphate kinase B Pathway interactions Phosphoric Monoester Hydrolases Phosphotransferases Play Protein Isoforms Proteins Receptor Activation Recruitment Activity Regulation Role Side Signal Pathway T-Cell Activation T-Cell Receptor T-Lymphocyte Tail immunological synapse in vivo inhibitor/antagonist insight myotubularin novel overexpression phosphatidylinositol 3-phosphate phosphohistidine protein-histidine kinase public health relevance release of sequestered calcium ion into cytoplasm

项目摘要

DESCRIPTION (provided by applicant): The Ca2+-activated K+ channel, KCa3.1, is required for Ca2+ influx and the subsequent activation of B and T cells. Inhibitors of KCa3.1 are in development to treat autoimmune diseases and transplant rejection, underscoring the importance in understanding how these channels are regulated. Our studies on the regulation of KCa3.1 have uncovered a completely new signaling pathway required for the reactivation of human CD4 T cells. This pathway includes a potentially novel phosphatidylinositol 3 Kinase (PI3K) isoform, phosphatidylinositol 3-Phosphate (PI(3)P), and a mammalian histidine kinase, Nucleoside Diphosphate Kinase B (NDPK-B), that are required for KCa3.1 channel activation. We found that NDPK-B functions downstream of PI(3)P to activate KCa3.1 by phosphorylating H358 in KCa3.1's carboxyterminal (CT) tail. Moreover, we have identified 2 new negative regulators of T cell activation, the PI(3)P phosphatase myotubularin related protein 6 (MTMR6) and the histidine phosphatase, phosphohistidine phosphatase-1 (PHPT-1), which inhibit KCa3.1 by dephosphorylating PI(3)P and KCa3.1 respectively. The major goal of this proposal is to further explore the mechanisms whereby these molecules regulate KCa3.1 and their biological relevance to T cell activation and disease. Specific Aim (SA) 1 will identify the signaling pathway in CD4 T cells that is critical for generating the PI(3)P pool that mediates KCa3.1 channel activation and the mechanism whereby PI(3)P functions upstream to regulate NDPK-B. SA2 will determine whether T cell receptor (TCR) stimulation regulates the redistribution of NDPK-B, KCa3.1, MTMR6, and the PI3K isoform identified in SA1 to the immunological synapse (IS), and the consequences this plays in the regulation of KCa3.1 channel activity. SA3 will identify the histidine phosphatase that negatively regulates KCa3.1 channel activity and its role in T cell biology. Our recent data indicates that the histidine phosphatases PHPT-1 and phospholysine phosphohistidine inorganic pyrophosphate phosphatase (LHPP) are negative regulators of KCa3.1 and function to reverse the activation of KCa3.1 by NDPK-B by dephosphorylating histidine 358 (H358) in the CT of KCa3.1.The Ca2+-activated K+ channel, KCa3.1, is required for Ca2+ influx and the subsequent activation of B and T cells. Inhibitors of KCa3.1 are in development to treat autoimmune diseases and transplant rejection, underscoring the importance in understanding how these channels are regulated. Public Health Relevance: Our studies on the regulation of KCa3.1 have uncovered new signaling pathways that functions as both positive and negative regulators of KCa3.1 channel activity. Interfering pharmacologically with molecules we found that positively regulate KCa3.1 may identify novel drug targets to treat transplant rejection and autoimmune disease. On the flip side, abnormal expression or activity of molecules we identified that negative regulate KCa3.1 could provide new insight into autoimmune diseases.

描述（由申请人提供）：Ca2+ 激活的 K+ 通道 KCa3.1 是 Ca2+ 流入以及随后 B 和 T 细胞激活所必需的。 KCa3.1 抑制剂正在开发中，用于治疗自身免疫性疾病和移植排斥，这强调了了解这些通道如何调节的重要性。我们对 KCa3.1 调节的研究发现了人类 CD4 T 细胞重新激活所需的全新信号通路。该通路包括 KCa3.1 通道所需的潜在新型磷脂酰肌醇 3 激酶 (PI3K) 亚型、磷脂酰肌醇 3-磷酸 (PI(3)P) 和哺乳动物组氨酸激酶、核苷二磷酸激酶 B (NDPK-B)激活。我们发现 NDPK-B 在 PI(3)P 下游发挥作用，通过磷酸化 KCa3.1 羧基末端 (CT) 尾部的 H358 来激活 KCa3.1。此外，我们还发现了 2 个新的 T 细胞激活负调节因子，即 PI(3)P 磷酸酶肌管蛋白相关蛋白 6 (MTMR6) 和组氨酸磷酸酶磷酸组氨酸磷酸酶-1 (PHPT-1)，它们通过去磷酸化来抑制 KCa3.1分别为PI(3)P和KCa3.1。该提案的主要目标是进一步探索这些分子调节 KCa3.1 的机制及其与 T 细胞激活和疾病的生物学相关性。具体目标 (SA) 1 将确定 CD4 T 细胞中的信号传导通路，该通路对于生成介导 KCa3.1 通道激活的 PI(3)P 库至关重要，以及 PI(3)P 发挥上游功能以调节 NDPK-B 的机制。 SA2 将确定 T 细胞受体 (TCR) 刺激是否调节 NDPK-B、KCa3.1、MTMR6 和 SA1 中识别的 PI3K 同工型向免疫突触 (IS) 的重新分配，以及这在 KCa3 调节中所起的作用.1 渠道活动。 SA3 将识别负调节 KCa3.1 通道活性的组氨酸磷酸酶及其在 T 细胞生物学中的作用。我们最近的数据表明，组氨酸磷酸酶 PHPT-1 和磷酸赖氨酸磷酸组氨酸无机焦磷酸磷酸酶 (LHPP) 是 KCa3.1 的负调节因子，并通过使组氨酸 358 (H358) 去磷酸化来逆转 NDPK-B 对 KCa3.1 的激活。 KCa3.1 的 CT。Ca2+ 激活的 K+ 通道 KCa3.1 是 Ca2+ 所必需的B 细胞和 T 细胞的流入和随后的激活。 KCa3.1 抑制剂正在开发中，用于治疗自身免疫性疾病和移植排斥，这强调了了解这些通道如何调节的重要性。公共健康相关性：我们对 KCa3.1 调节的研究发现了新的信号传导途径，这些信号传导途径可作为 KCa3.1 通道活动的正调节器和负调节器。通过对分子进行药理学干扰，我们发现正向调节 KCa3.1 可能会识别出治疗移植排斥和自身免疫性疾病的新药物靶点。另一方面，我们发现负调节 KCa3.1 的分子的异常表达或活性可以为自身免疫性疾病提供新的见解。