Early airway infection in a porcne model of cystic fibrosis

囊性纤维化跨膜传导调节因子（CFTR）的缺失导致肺部疾病， 囊性纤维化（CF）患者发病和死亡的主要原因。然而，尽管取得了显著进展， 经过基础、转化和临床研究的多个领域，我们仍然不知道CF肺为何会成为 被细菌占据根据联合培养和血清学结果，超过97%的患者 CF在3岁时感染铜绿假单胞菌。铜绿假单胞菌感染与肺部 功能下降和早期死亡。目前对CF患者铜绿假单胞菌的研究主要集中在 慢性感染对CF气道初始定植机制的了解有限 由于临床研究的难度、技术问题和伦理方面的考虑。虽然CF小鼠具有 在他们有限的生命周期中，他们不会发展出典型的呼吸道疾病， 人类研究气道细菌定植的主要障碍是缺乏动物模型 （非鼠），其在患有CF的人中复制肺病。我们培育出的猪， CFTR基因我们决定研究猪，因为它们的肺与人类非常相似。如果CFTR无效猪 被铜绿假单胞菌或任何其他细菌定殖，这将是一个非常令人兴奋的发现。它将 提供了一种动物模型，使研究人员能够充分描述CF的发病机制 肺部感染，特别是在最早期：CF气道的初始定植。我们的总体 假设CFTR缺乏将导致猪气道中细菌气道定殖。我们建议3 具体目标。 具体目标1：CFTR缺失猪对细菌和病毒定植易感。这一目标将是至关重要的， 确定CF肺和环境中遇到的微生物如何相互作用并导致CF 表型。我们还将确定CF猪是否发生气道阻塞。 具体目标2：CFTR无效猪的气道可以实验性地被CF细菌病原体定殖。 用感染人CF肺的细菌和猪呼吸道细菌感染气道 病原体将使我们能够研究疾病的早期发病机制，阐明对感染的反应， 并为今后的研究提供了模型。 具体目的3：猪中CFTR的缺乏导致粘膜纤毛清除异常，抗菌剂缺陷 活性和/或改变的巨噬细胞的吞噬细胞功能。我们将调查CFTR是否在每个 这是猪体内的抗菌机制之一我们将研究猪CF气道清洁的能力 细菌大小的颗粒，运输硫氰酸盐，生成次硫氰酸盐， 猪嗜中性粒细胞和巨噬细胞中的吞噬体。

Loss of the cystic fibrosis transmembrane conductance regulator (CFTR) causes lung disease that is the major cause of morbidity and mortality in people with cystic fibrosis (CF). Yet despite outstanding progress in several areas of basic, translational and clinical research, we still do not know why do CF lungs become colonized with bacteria. On the basis of combined culture and serologic results, over 97% of patients with CF are infected with P. aeruginosa by the age of 3. Infection with P. aeruginosa is associated with pulmonary function decline and early mortality. Most current research on P. aeruginosa in patients with CF focuses on chronic infection. Knowledge of the mechanisms that allow the initial colonization of the CF airways is limited by the difficulty of clinical research, technical problems and ethical considerations. Although CF mice have been developed, during their limited lifespan they do not develop the airway disease typically found in humans. A major impediment to studying airway colonization with bacteria is the lack of an animal model (non-murine) that replicates the lung disease in humans with CF. We generated pigs with disruption of the CFTR gene. We decided to study pigs because their lungs are very similar to humans. If the CFTR-null pigs are colonized with P. aeruginosa or any other bacteria, it will be an extremely exiting discovery. It will provide an animal model that will allow investigators to fully describe mechanistically the pathogenesis of CF lung infections, in particular at the earliest period: the initial colonization of the CF airways. Our overarching hypothesis is that lack of CFTR will result in bacterial airway colonization in pig airways. We propose 3 specific aims. Specific Aim 1: CFTR null pigs are susceptible to bacteria and viral colonization. This aim will be critical in establishing how the CF lung and environmentally encountered microorganisms interact and lead to the CF phenotype. We will also determine whether CF pigs develop airway obstruction. Specific Aim 2: The airways of CFTR null pigs can be experimentally colonized by CF bacterial pathogens. Challenging the airways with bacteria that infect human CF lungs and with porcine respiratory bacterial pathogens will allow us to investigate the early pathogenesis of disease, elucidate the response to infection, and provide models for many future studies. Specific Aim 3: Lack of CFTR in pig results in abnormal mucociliary clearance, defective antimicrobial activity, and/or altered phagocyte function of macrophages. We will investigate if CFTR plays a role in each one of these antimicrobial mechanisms in pigs. We will investigate the ability of pig CF airways to clean bacterial-sized particles, transport thiocyanate, generate hypothiocyanite, and the acidification of phagosomes in both pig neutrophils and macrophages.