ATG16L1 T300A: genetics to biology

描述（由申请人提供）：最近的遗传分析显示，自噬在克罗恩病（CD）1中起着意想不到的作用，揭示了自噬基因ATG16L1的编码多态性与CD4风险增加相关。然而，ATG16L1的生物学功能仍然相对未知，T300A风险多态性易患CD的机制尚不清楚。本应用中提出的实验将对ATG16L1 T300A的生物学特性产生新的见解，并为预防或治疗CD的新方法提供线索。我们的总体假设是ATG16L1是自噬所必需的，ATG16L1 T300A CD风险多态性通过调节细胞特异性防御反应来促进疾病，而细胞特异性防御反应是维持肠粘膜稳态的核心。为了验证这一假设，我们建议确定ATG16L1 T300A在细胞对应激和促炎配体的反应中的功能作用，并检查自噬突变对肥大细胞功能和Paneth细胞功能所必需的分泌程序的影响。此外，我们将研究导致T300A相关表型的分子决定因素，并提出一种新的基因调控网络分析方法，这将有助于深入了解ATG16L1 T300A在CD中的功能。为了研究这些问题，我们将采用几种遗传方法。使用实验室开发的两种独特的小鼠模型（Atg16l1 T300A敲入小鼠和Atg16l1的条件缺失）以及来自健康个体和乳糜泻患者的原代外周血细胞携带这种多态性。所描述的初步数据证明了该建议具体目标的可行性。这些研究的最终目的是了解ATG16L1激活引起对CD患者异常免疫反应的详细分子机制。这个核心问题的答案将具有直接的临床意义。目的1)利用微生物因素的微扰分析来确定在与环境（微生物）相互作用的背景下，ATG16L1 T300A如何参与CD敏感性。目的2)揭示与ATG16L1 T300A相关的表型在涉及分泌的非规范自噬途径中的潜在机制。目的3)确定与CD患者疾病风险相关的ATG16L1 T300A的分子决定因素。目的4)鉴定ATG16L1 t300a特异性调控网络模块，以深入了解参与CD发病机制的自噬相关表型。

DESCRIPTION (provided by applicant): Recent genetic analyses have shown an unsuspected role for autophagy in Crohn's disease (CD)1, revealing a coding polymorphism in the autophagy gene ATG16L1 that is associated with increased risk of CD4. However, the biological function of ATG16L1 remains relatively unexplored, and the mechanism whereby the T300A risk polymorphism predisposes to CD is not known. The experiments proposed in this application will yield novel insights into the biology of ATG16L1 T300A and provide clues to novel means to preventing or treating CD. Our overarching hypothesis is that ATG16L1 is required for autophagy and that the ATG16L1 T300A CD risk polymorphism contributes to disease by regulating cell-specific defense responses that are central to maintaining intestinal mucosal homeostasis. To test this hypothesis, we propose to determine the functional effects of ATG16L1 T300A in the cellular response to stress and pro-inflammatory ligands and to examine the effects of autophagy mutations in secretion programs essential for mast cell function and Paneth cell function. Furthermore, we will investigate the molecular determinants that contribute to T300A-associated phenotypes and present a novel approach for analysis of gene regulatory networks that will offer insight into the function of ATG16L1 T300A in CD. To investigate these questions, we will employ several genetic approaches, using two unique mouse models developed in the lab (Atg16l1 T300A knock-in mice and conditional deletion of Atg16l1) as well as primary peripheral blood cells from healthy individuals and CD patients bearing this polymorphism. The preliminary data described demonstrate the feasibility of the specific aims of this proposal. The ultimate aim of these studies is to understand the detailed molecular mechanism of ATG16L1 activation that gives rise to aberrant immunological responses to patients with CD. Answers to this central question will have direct clinical implications. Aim 1) Use perturbational profiling by microbial factors to determine how ATG16L1 T300A is involved in CD susceptibility in the context of interactions with the environment (microbes). Aim 2) Unravel underlying mechanisms of phenotypes associated with ATG16L1 T300A in non-canonical autophagy pathways that involve secretion. Aim 3) Identify the molecular determinants of ATG16L1 T300A that contribute to disease risk in CD patients. Aim 4) Identify ATG16L1 T300A-specific regulatory network modules to gain insights into autophagy- associated phenotypes involved in CD pathogenesis.