The role of mucin-protein interactions in the innate defense of the lung

描述(申请人提供)：呼吸道上皮粘膜屏障是一个强大的天然免疫系统的心脏，维持着下面的上皮表面。在最广泛的层面上，这项建议的主要科学目标是阐明由称为粘蛋白(MUC5B和MUC5AC)的非常大的糖蛋白(MUC5B和MUC5AC)与其他保护性生物分子通过不稳定的相互作用形成的呼吸道凝胶层的组织，并评估这些相互作用在呼吸道粘液完整性中的作用，作为治疗干预的基本先决条件。我们的假设是，正常的呼吸道粘液是高度结构化的，含有超过100种蛋白质，形成不同的蛋白质复合体，其中许多以这些粘蛋白为中心。这些复合体构成了一个离散的分泌实体，我们称之为‘粘蛋白相互作用体’。我们认为，凝胶性质产生于粘蛋白和蛋白质之间的动态相互作用，这些结构产生粘液的特定流变性，通过咳嗽和清流来调节粘液的清除。这一提议将改变粘蛋白是赋予粘液大部分流变性的唯一分子的范式，并最终将使人们更好地理解这些相互作用作为肺的天然防御所起的作用。在测试这些假说时，使用了广泛的生化、分子和细胞生物学方法，我们建议：1)确定显示特定粘蛋白结合证据的目标蛋白质组；2)确定粘蛋白-蛋白质相互作用所需的结构域；以及3)评估粘蛋白-蛋白质相互作用对粘液表面和整体流变性的影响。如果这项提议的目标得以实现，它们将增加我们对蛋白质组成和呼吸道分泌物功能之间关系的认识和理解。这些知识是知情的治疗干预的必要先决条件。 公共卫生相关性：这项建议将检查由非常大的糖蛋白(称为粘蛋白)通过不稳定的相互作用与其他保护性生物分子结合形成的呼吸道凝胶层的组织，并评估它们对呼吸道粘液完整性和功能的作用。这是一个新的提议，将改变粘蛋白是唯一赋予粘液大部分流变性的分子的范式，如果是真的，最终将使人们更好地理解这些相互作用作为肺的天然防御所起的作用。

DESCRIPTION (provided by applicant): The airway epithelial mucosal barrier is the heart of a powerful innate immune system that maintains the underlying epithelial surface. At the broadest level, the major scientific goal of this proposal is to elucidate the organization of the airway gel layer, which is formed by very large glycoproteins termed mucins (MUC5B and MUC5AC) coupled with other protective biomolecules through labile interactions, and assess the role of these interactions in airway mucus integrity as an essential pre-requisite for therapeutic intervention. Our hypothesis is that normal airway mucus is highly structured, containing an excess of 100 proteins that form distinct protein complexes many of which are centered around these mucins. These complexes constitute a discrete secretory entity we call the 'mucin interactome'. We propose that gel properties emerge from a dynamic interplay between the mucins and proteins and that these structures engender specific rheological properties of mucus that tune it to removal by cough and flow clearance. This proposal will change the paradigm that mucins are the only molecules that give most of the rheological properties to mucus and will ultimately lead to a greater understanding of the role of these interactions as an innate defense of the lung. In testing these hypotheses, using a broad range of biochemical, molecular and cellular biology methods, we propose: 1) To determine our target panel of proteins that show evidence of specific mucin binding; 2) To determine the domains required for the mucin-protein interactions and 3) To assess the effects of mucin-protein interactions on the surface and bulk rheological properties of the mucus. If the goals of this proposal are achieved, they will increase our knowledge and understanding of the relationship between protein composition and the function of airway secretions. Such knowledge is an essential pre-requisite for informed therapeutic intervention. PUBLIC HEALTH RELEVANCE: This proposal will examine the organization of the airway gel layer formed by very large glycoproteins, termed mucins, coupled to other protective biomolecules through labile interactions, and assess their role on airway mucus integrity and function. This is a novel proposal and will change the paradigm that mucins are the only molecules that give most of the rheological properties to mucus and, if true, will ultimately lead to a greater understanding of the role of these interactions as an innate defense of the lung.