Optimizing aerosol gene delivery and expression in the ovine lung

Area of Science:

• Pulmonary Medicine
• Gene Therapy
• Animal Models

Background:

• Cystic fibrosis (CF) requires effective gene therapy delivery methods.
• Large animal models are crucial for preclinical testing of CF therapies.
• Optimizing gene transfer agents (GTAs) for lung delivery is essential.

Purpose of the Study:

• To establish and validate the sheep as a large animal model for cystic fibrosis gene therapy.
• To assess the delivery, efficacy, and safety of aerosolized GTAs in the ovine lung.
• To investigate dose-response relationships and the impact of adjunct therapies.

Main Methods:

• Administered aerosolized gene transfer agents (GTAs), including plasmid DNA (pDNA):GL67 and pDNA:PEI complexes, to the ovine lung using a clinical nebulizer.
• Evaluated GTA distribution and reporter gene expression.
• Assessed dose-response relationships and the effect of glycopyrrolate as an adjunct therapeutic.
• Compared toxicity of aerosol administration versus direct instillation.

Main Results:

• Demonstrated successful GTA distribution and reporter gene expression throughout the sheep lung.
• The sheep model effectively differentiated between GTA doses.
• The anticholinergic glycopyrrolate enhanced transgene expression.
• Aerosol administration reduced dose-related GTA toxicity compared to direct instillation.

Conclusions:

• The ovine model is suitable for optimizing cystic fibrosis gene therapy protocols.
• Aerosolized GTAs show promise for CF gene therapy delivery in a large animal model.
• This model provides confidence for advancing toward human clinical studies.