Structure-based inhibition of chemokine signaling in the inflamed pancreas

修改后的项目摘要/摘要部分 该项目的目标是确定 CCL28 在慢性胰腺炎中的作用，并使用基于结构的药物发现方法来鉴定这种分泌蛋白的小分子抑制剂。 CCL28 是一种粘膜趋化因子，通过招募表达 G 蛋白偶联受体 CCR10 的调节性 T 细胞 (Treg) 来促进多种器官中的肿瘤生长。根据我们已发表的初步结果，我们假设胰腺导管上皮细胞分泌趋化因子 CCL28 也会导致慢性炎症发展为恶性疾病。我们假设抑制 CCL28 活性将改变胰腺粘膜微环境，从而减少癌前炎症并增强现有化疗和免疫疗法的活性。为了实现这一目标，我们提出了三个概念上相关但实验上独立的具体目标。首先，我们将在慢性胰腺炎动物模型中测试我们的机制假设，以通过实验证明 CCL28 通过 CCR10 的活性在体内纤维炎症反应中发挥关键作用，并开发可用于筛选有前途的抑制剂的体外模型（目标 1）。我们将使用 NMR 和分子模型详细绘制 G 蛋白偶联受体 CCR10 识别 CCL28 的关键要素，并且我们将使用最先进的受体药理学检测平台定义该趋化因子受体的完整细胞内信号传导谱（目标 2）。利用已解析的 CCL28 NMR 结构和对其磺基酪氨酸结合袋的了解，我们将采用 Volkman 实验室开发的基于结构的策略，该策略能够发现结合特定趋化因子靶标并抑制细胞迁移的小分子（目标 3）。总的来说，拟议的研究将为我们理解以下方面提供根本性进展：（1）胰腺中的Treg功能和病理生理学；（2）在很大程度上未经检验的趋化因子信号传导轴中配体-受体选择性和GPCR药理学的结构基础；以及（3）粘膜趋化因子在慢性炎症和肿瘤促进界面处的成药性。

Modified Project Summary/Abstract Section The goal of this project is to establish the role of CCL28 in chronic pancreatitis and use structure-based drug discovery methods to identify small molecule inhibitors of this secreted protein. CCL28 is a mucosal chemokine that promotes tumor growth in a variety of organs by recruiting regulatory T cells (Tregs) that express the G protein-coupled receptor CCR10. Based on our published and preliminary results, we postulate that secretion of the chemokine CCL28 by pancreatic ductal epithelial cells also drives chronic inflammation that progresses to malignant disease. We hypothesize that inhibition of CCL28 activity will alter the pancreatic mucosal microenvironment in a manner that reduces pre-malignant inflammation and enhances the activity of existing chemotherapeutics and immunotherapies. To achieve this objective, we propose three conceptually linked but experimentally independent specific aims. First, we will test our mechanistic hypothesis in animal models of chronic pancreatitis, to demonstrate experimentally that CCL28 activity through CCR10 plays a key role in the fibroinflammatory response in vivo and develop an in vitro model that can be used to screen promising inhibitors (aim 1). Key elements of CCL28 recognition by its G protein-coupled receptor CCR10 will be mapped in detail using NMR and molecular modeling, and we will define the complete intracellular signaling profile of this chemokine receptor using state-of-the-art assay platforms for receptor pharmacology (aim 2). Using the solved NMR structure of CCL28 and knowledge of its sulfotyrosine binding pocket, we will employ a structure-based strategy developed in the Volkman lab that enables the discovery of small molecules that bind a specific chemokine target and inhibit cell migration (aim 3). Collectively, the proposed studies will provide fundamental advances in our understanding of (1) Treg function and pathophysiology in the pancreas, (2) the structural basis for ligand-receptor selectivity and GPCR pharmacology in a largely unexamined chemokine signaling axis, and (3) the druggability of a mucosal chemokine at the tumor-promoting interface of chronic inflammation and neoplasia.