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：
10666256
负责人：
Sudarshan K Rajagopal
金额：
$ 4.2万
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/10666256
关键词：
Adaptor Signaling Protein Address Agonist Allosteric Regulation Atherosclerosis Biological CXC chemokine receptor 3 CXCL9 gene CXCR3 gene Cell physiology Chemotaxis Clustered Regularly Interspaced Short Palindromic Repeats Complex Contact hypersensitivity Creativeness Development Disease Drug Targeting Endocytosis Endosomes FDA approved Fostering G-Protein-Coupled Receptors 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 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 inflammatory modulation 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

项目摘要

ABSTRACT 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 cognate chemokine ligands for a given CKR and a lack of knowledge regarding how the signaling pathways activated by CKRs regulate immune cell function and in- flammation. 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 cognate 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) dif- ferentially 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 promoting 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 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 induce unique receptor and β-arrestin conformations that favor “location bi- ased” endosomal signaling that promotes a T cell transcriptional response that results in different patterns of inflammation. To address our objective, first, we will determine how the receptor:ligand complex promotes biased responses through allosteric regulation of effectors. We have found that CXCR3 biased agonists promote differ- ent 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 future research on biased agonists as CXCR3 therapeutics and serve as a model for targeting other CKRs.

抽象的 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的多个同源趋化因子配体之间的潜在冗余和缺乏关于CKRS激活信号通路如何调节免疫细胞功能和IN-的知识燃烧。这是针对趋化因子系统的药物的关键未满足需求。这置于上下文我小组在趋化因子受体CXCR3上的工作。我们已经证明了CXCR3的同源配体， CXCL9、10和11充当偏见的激动剂，从一个定量和质量上产生与一个偏见的信号另一种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。在上一个项目期，我们已经确定了小分子G蛋白和β-arrest蛋白偏向的CXCR3激动剂（1）差异 cxcr3下游的狂热激活信号通路，（2）在小鼠模型中具有明显的影响 T细胞介导的炎症性皮肤病。这些发现表明G蛋白和β-arrestin在促进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。总体该提议的目的是确定偏见的激动剂如何促进导致不同的效应子构象对信号传导的不同模式，导致T细胞功能和注射的变化。我们的中心假设是β-arrestin偏置的激动剂会诱导独特的受体和β-arrest素构象，有利于“位置” ASED”内体信号传导，促进T细胞转录响应，从而导致不同的模式炎。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偏见通过变构调节作用的反应。我们发现CXCR3偏见的激动剂促进了不同的 - ENTβ-arrest蛋白介导的作用，我们将通过使用接收器突变体进一步探索。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CXCR3疗法的未来研究，是针对其他CKR的模型。