Mechanism of anti-inflammatory role of MUC1 during airway bacterial infection

描述（由申请人提供）：尽管炎症是肺部感染期间宿主的一种重要防御机制，但及时解决炎症对于宿主预防不受控制的炎性细胞导致的肺损伤至关重要。 最近，我们发现MUC1，一种表达于气道上皮细胞顶面的膜系粘蛋白，具有在气道铜绿假单胞菌（Pa）感染结束时通过抑制Toll样受体（TLR）5信号传导来控制炎症的能力。 在这个更新的应用程序中，我们建议阐明的机制，MUC1抑制TLR5在Pa感染。 我们假设MUC1在Pa感染期间通过与TLR 5的直接相互作用抑制TLR 5信号传导，所述直接相互作用通过EGFR的活化介导，并提出以下目的来检验该假设。 在目的1中，我们将通过使用遗传学和免疫学方法检测培养的上皮细胞中MUC1和TLR5之间的分子相互作用的细节，来确定MUC1在气道Pa感染期间的抗炎作用是否是由于其与TLR5的直接相互作用。 在目标2中，我们将使用遗传学和免疫学方法确定MUC1与TLR5的相互作用是否受培养细胞中EGFR对MUC1的酪氨酸磷酸化的调节，并且EGFR的这种作用将使用EGFR缺陷小鼠进行验证。 在最终的目标3中，将使用培养的细胞和体内动物两者来真实的实时监测从Pa感染到MUC1的炎症消退所发生的事件的完整序列。 这些实验的成功完成将提供与气道Pa感染期间MUC1的抗炎作用相关的详细的分子相互作用，并且应该提供对控制慢性炎性肺病（诸如COPD和囊性纤维化）的过度和延长的肺部炎症特征的可能的治疗策略的见解。

DESCRIPTION (provided by applicant): Although inflammation is an essential host defense mechanism during lung infection, its timely resolution is critical for the host to prevent lung injuries resulting from uncontrolled inflammatory cells. Recently we discovered that MUC1, one of the membrane-tethered mucins expressed on the apical surface of airway epithelial cells, has an ability to control inflammation at the end of airway Pseudomonas aeruginosa (Pa) infection by suppressing toll-like receptor (TLR)5 signaling. In this renewal application, we propose to elucidate the mechanism by which MUC1 suppresses TLR5 during Pa infection. We hypothesize that MUC1 suppresses TLR5 signaling during Pa infection by a direct interaction with TLR5 which is mediated through activation of EGFR and propose the following aims to test the hypothesis. In Aim 1, we will determine whether anti-inflammatory effect of MUC1 during airway Pa infection is due to its direct interaction with TLR5 by examining the details of molecular interactions between MUC1 and TLR5 in cultured epithelial cells using both genetic and immunological methods. In Aim 2, we will determine whether the interaction of MUC1 with TLR5 is regulated by tyrosine phosphorylation of MUC1 by EGFR in cultured cells using genetic as well as immunological methods and such role of EGFR will be verified using EGFR deficient mice. In the final Aim 3, the complete sequence of the events that take place from Pa infection to the resolution of inflammation by MUC1 will be monitored in real time using both cultured cells and in vivo animals. Successful completion of these experiments will provide the detailed molecular interactions associated with the anti-inflammatory role of MUC1 during airway Pa infection and should provide insights into possible therapeutic strategies to control excessive and prolonged lung inflammation characteristic of chronic inflammatory lung diseases such as COPD and cystic fibrosis.