Cell-specific Delivery of RNAi to Pulmonary Alveolar Macrophages in vivo

描述（由申请人提供）：将干扰RNA递送至肺组织为开发用于多种肺部疾病的新型抗病毒和抗炎疗法提供了机会。用于RNA干扰（RNAi）的构建体的体内递送，如已用于阻断流感和副流感病毒肺部感染，是治疗肺部疾病的特别令人兴奋的方法，因为它提供了这些分子到靶器官的潜在组织特异性递送。然而，用这些方法转导的细胞类型尚不清楚，一些研究人员发现了暴露于这种递送途径的小鼠的非肺组织中的非特异性效应。此外，肺部潜在的不良反应，如炎症的激活，是限制RNAi技术应用的问题。细胞特异性、组织特异性地将RNAi递送到肺内的免疫细胞将是一个重大的进步，使得能够潜在地治疗以炎症为特征的许多疾病，包括哮喘和肺气肿。该授权申请提供了初步数据，证明了一种新的基于慢病毒的系统，该系统允许将RNAi细胞特异性、组织特异性体内递送至驻留的肺泡巨噬细胞。该提案的具体目的是测试这种靶向体内递送方法的有效性，并了解该系统的生物学，包括筛选特异性和潜在的脱靶效应。最后，将该系统应用于小鼠肺泡巨噬细胞中NF-κ B信号传导的体内敲低和烟草烟雾诱导的肺部炎症的治疗。

DESCRIPTION (provided by applicant): The delivery of interfering RNAs to lung tissue provides an opportunity to develop novel anti-viral and anti-inflammatory therapies for a variety of lung disorders. Intratracheal delivery of constructs for RNA interference (RNAi), as has been used to block influenza and parainfluenza lung infections, is a particularly exciting approach to treating lung disease because it offers potentially tissue-specific delivery of these molecules to a target organ. However, the cell types transduced with these methods are not yet known, and some investigators have found concerning non-specific effects in non-pulmonary tissues of mice exposed to this route of delivery. In addition, the potential for adverse effects in the lung, such as activation of inflammation are concerns that limit application of RNAi technology. Cell-specific, tissue-specific delivery of RNAi to immune cells within the lung would be a significant advance enabling potential treatment of many diseases characterized by inflammation, including asthma and emphysema. This grant application presents preliminary data demonstrating a novel lentiviral-based system that allows the cell-specific, tissue-specific in vivo delivery of RNAi to resident alveolar macrophages. The specific aims of this proposal are designed to test the efficacy of this targeted in vivo delivery method and to understand the biology of this system, including screening for specificity and potential off-target effects. Finally, the system is applied for in vivo knockdown of NF-kB signaling in mouse alveolar macrophages and the treatment of tobacco smoke- induced lung inflammation.