Electrostatic Effects in Cystic Fibrosis Mucous

描述(由申请人提供)：粘性粘液在呼吸道中的堆积是长期细菌感染、呼吸衰竭以及囊性纤维化(CF)最终死亡的主要原因。呼吸道感染引起的炎症反应导致细胞骨架蛋白、DNA等聚电解质的病理性释放，导致纤维粘液中阳离子配体稳定的大聚集体的静电聚集，导致内源性抗菌多肽的滞留，导致抗菌功能的丧失。这项建议的长期目标是在对CF粘液中静电相互作用的生物物理理解的基础上，合理设计恢复CF抗菌功能的治疗策略。该建议的三个具体目标是： (1)测定有无功能性囊性纤维化跨膜电导调节剂(CFTR)的培养的人呼吸道上皮细胞株表达的呼吸道表面液体(ASL)内的离子强度。 (2)定量表征内源性抗菌肽与阴离子聚电解质在碱性磷酸酶生理条件下的静电复合体的结构形式和热力学稳定性，并设计生物物理治疗策略来解离这些被隔离的抗菌肽。 (3)通过定向分子进化，开发一种模拟阳离子乳铁蛋白的生物膜抑制作用的阴离子DNAzyme，但由于其相反的电荷而不会被隔离。

DESCRIPTION (provided by applicant): The accumulation of viscous mucus in the airways is the primary cause of long-term bacterial infections, respiratory failure, and eventually death in cystic fibrosis (CF). The inflammatory response to infections in the airways leads to the pathological release of cytoskeletal proteins, DNA and other polyelectrolytes, which cause the electrostatic assembly of large aggregates stabilized by cationic ligands in CF mucus, and results in the sequestration of endogenous antibacterial polypeptides and contributes to the loss of antimicrobial function. The long-range goal of this proposal is the rational design of therapeutic strategies in the restoration of antimicrobial function in CF, based on a biophysical understanding of electrostatic interactions in CF mucus. The three specific aims of the proposal are: (1) To determine the ionic strength within the airway surface liquid (ASL) expressed on cultured human airway epithelial cell lines with and without a functioning cystic fibrosis transmembrane conductance regulator (CFTR). (2) To characterize quantitatively the structural form and thermodynamic stability of electrostatic complexes of endogenous antibacterial peptides and anionic polyelectrolytes in the ASL under CF physiological conditions, and design biophysical therapeutic strategies to unbind these sequestered antibacterial peptides. (3) To develop, via directed molecular evolution, an anionic DNAzyme which mimics the biofilm suppression action of cationic lactoferrin, but will not be sequestered due to its opposite charge.