Biasing CXCR3 Signaling to Modulate the Inflammatory Response

偏置 CXCR3 信号传导来调节炎症反应

基本信息

批准号：
10442305
负责人：
Sudarshan K Rajagopal
金额：
$ 35.72万
依托单位：
DUKE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-09-20 至 2026-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10442305
关键词：
Adaptor Signaling Protein Address Agonist Allosteric Regulation Arrestins Atherosclerosis Biological CXC chemokine receptor 3 CXCL9 gene CXCR3 gene Cell physiology Chemotaxis Clustered Regularly Interspaced Short Palindromic Repeats Complex Development Disease Drug Design Drug Modelings Drug Targeting Endocytosis FDA approved Fostering Future G-Protein-Coupled Receptors GTP-Binding Protein alpha Subunits, Gs GTP-Binding Proteins Genetic Transcription Goals Health Heterotrimeric GTP-Binding Proteins Immediate-Early Genes Immune In Vitro Inflammation Inflammatory Inflammatory Bowel Diseases Inflammatory Response Knowledge Lead Ligands Location Malignant Neoplasms Mediating Mission Mitogen-Activated Protein Kinases Modeling Molecular Conformation Mutant Strains Mice Output Pattern Pertussis Toxin Phosphorylation Play Receptor Inhibition Regulation Research Role Serum Response Element Signal Pathway Signal Transduction System T cell regulation T-Lymphocyte Testing Therapeutic United States National Institutes of Health Work antagonist beta-arrestin cell motility chemokine chemokine receptor clinically relevant drug development improved in vivo innovation knock-down mouse model mutant new therapeutic target novel drug class novel therapeutics prevent public health relevance receptor receptor internalization recruit response skin disorder small molecule targeted treatment

项目摘要

CXCR3 is a chemokine receptor (CKR) that plays a central role in inflammation through its regulation of T cell migration and function. Despite the established clinical relevance of CKRs in disease, there are only three FDA approved drugs that target the entire chemokine system, which consists of approximately twenty receptors and fifty ligands that regulate nearly every aspect of inflammation. Reasons for this difficulty in CKR drug develop- ment include the potential redundancy between multiple chemokine ligands for a given CKR and a lack of knowledge of how the signaling pathways activated by CKRs regulate immune cell function and inflammation. Thus, there is a critical unmet need for drugs targeting the chemokine system. This puts into context work from my group on the chemokine receptor CXCR3. We have shown that the chemokine ligands of CXCR3, CXCL9, 10 and 11, act as biased agonists, generating quantitatively and qualitatively distinct signals from one another through their interactions with heterotrimeric G proteins and β-arrestin adapter proteins. In the previous project period, we have identified small-molecule G protein- and β-arrestin-biased CXCR3 agonists that (1) differentially activate signaling pathways downstream of CXCR3, and (2) have distinct effects in a mouse model of T-cell- mediated inflammatory skin disease. These findings suggest distinct roles for G proteins and β-arrestin in pro- moting the CXCR3-mediated inflammatory response. The long-term goal of our research is to determine the mechanisms underlying biased agonism to develop novel therapies targeting CKRs in inflammation. The overall objective of this proposal is to determine how CXCR3 biased agonists promote different effector conformations that lead to distinct patterns of signaling resulting in changes in T cell function and inflammation. Our central hypothesis is that β-arrestin-biased agonists promote unique receptor and β-arrestin conformations that favor “location-biased” endosomal signaling that promotes a unique transcriptional response in T cells and inflamma- tion. To address our objective, first, we will determine how the receptor:ligand complex promotes biased re- sponses through allosteric regulation of effectors. We have found that CXCR3 biased agonists promote different β-arrestin-mediated effects, which we will explore further by using receptor mutants. Then, we will determine how endosomal signaling and location bias contribute to CXCR3 biased signaling. We have found that some CXCR3 biased agonists promote transcription that can be prevented by inhibiting receptor endocytosis. Lastly, we will determine how CXCR3 G protein- and β-arrestin-mediated signaling pathways contribute to T cell function and the inflammatory response. We will use CXCR3 mutants to test the contributions of specific signaling path- ways to T cell chemotaxis in vitro and inflammation in vivo. This project explores an innovative approach to study CXCR3 signaling that will provide an understanding of CXCR3 regulation of the inflammatory response by the selective activation of G proteins and β-arrestins. The research is significant as it will lay the groundwork for research on biased agonists as therapies targeting CXCR3 and serve as a model for drug design at GPCRs.

CXCR3是一种趋化因子受体（CKR），通过调节T细胞在炎症中起着核心作用迁移和功能。尽管CKR在疾病中已经建立了临床相关性，但只有三个FDA 批准针对整个趋化因子系统的药物，该药物由大约二十个受体和几乎调节炎症的各个方面的五十个配体。 CKR药物开发困难的原因 - MENT包括给定CKR的多种趋化因子配体之间的潜在冗余和缺乏了解CKRS激活信号通路如何调节免疫细胞功能和炎症的知识。这是针对趋化因子系统的药物的关键未满足需求。这将上下文工作我的小组在趋化因子受体CXCR3上。我们已经表明CXCR3，CXCL9的趋化因子配体， 10和11，充当偏见的激动剂，彼此之间产生定量和质量不同的信号通过它们与异源三聚体G蛋白和β-arrestin衔接蛋白的相互作用。在上一个项目中时期，我们已经确定了小分子G蛋白和β-arrestin偏向的CXCR3激动剂（1）差异化激活CXCR3下游的信号通路，（2）在T细胞的小鼠模型中具有明显的影响介导的炎症性皮肤病。这些发现表明，G蛋白和β-arrestin在促值中的不同作用移动CXCR3介导的炎症反应。我们研究的长期目标是确定偏向激动剂的机制开发了针对炎症中CKR的新型疗法。总体该建议的目的是确定CXCR3如何促进不同的效应子构象这导致了不同的信号传导模式，从而导致T细胞功能和注射的变化。我们的中心假设是β-arrestin偏置激动剂促进了有利于 “位置偏见”的内体信号传导，该信号促进了T细胞和炎症中独特的转录反应 tion。首先，为了解决我们的目标，我们将确定接收器：配体综合体如何促进有偏见的重新通过变构调节效应的发起。我们发现CXCR3有偏见的激动剂促进不同 β-甲介导介导的作用，我们将通过使用受体突变体进一步探索。然后，我们将确定内体信号传导和位置偏差如何促进CXCR3偏置信号传导。我们发现有些 CXCR3有偏的激动剂促进转录，可以通过抑制接收器内吞作用来预防。最后，我们将确定CXCR3 G蛋白 - 和β-arrest蛋白介导的信号通路如何有助于T细胞功能和炎症反应。我们将使用CXCR3突变体来测试特定信号通路的贡献 T细胞在体外和体内炎症的方法。该项目探讨了一种创新的研究方法 CXCR3信号传导将对CXCR3调节的炎症反应进行理解 G蛋白和β-钟RESIN的选择性激活。这项研究很重要，因为它将为对偏见激动剂作为针对CXCR3的疗法的研究，并作为GPCR的药物设计模型。