Modeling Pulmonary Disease Pathways Using Recombinant Adeno-Associated Virus 6.2

Area of Science:

• * Pulmonary disease research
• * Gene therapy and vector development
• * Animal modeling for human diseases

Background:

• * Viral vectors are crucial for creating animal models and studying gene function in vivo.
• * Current viral vectors face challenges including complex production, safety concerns, and immune responses that can confound results.
• * Adeno-associated virus (AAV) variant 6.2 is presented as a potential solution to these limitations for lung delivery applications.

Purpose of the Study:

• * To evaluate adeno-associated virus (AAV) variant 6.2 as an improved vector for lung delivery in mice.
• * To demonstrate the utility of AAV6.2 for generating disease models of asthma and pulmonary fibrosis.
• * To assess the safety and efficacy of AAV6.2 by comparing it to other viral vectors and testing its suitability for drug development.

Main Methods:

• * Adeno-associated virus (AAV) variant 6.2 vectors were engineered to express Interleukin-13 (IL-13) for asthma modeling and transforming growth factor-β1 (TGF-β1) for pulmonary fibrosis modeling.
• * Disease hallmarks were induced in mice, followed by phenotypic characterization, deep sequencing, micro-computed tomography (micro-CT) imaging, and lung function measurements.
• * Pharmacological interventions using an anti-IL-13 antibody and dexamethasone were performed on the asthma model.
• * Control experiments utilized stuffer control vectors and compared AAV6.2 with adenovirus-5 (Ad5) vectors to assess inflammatory responses.

Main Results:

• * AAV6.2 vectors successfully induced key features of severe asthma and pulmonary fibrosis in mouse models.
• * The AAV-IL-13 asthma model exhibited a distinct disease signature, and was suitable for testing anti-asthma compounds.
• * The AAV-TGF-β1 model displayed relevant pathophenotypes, validated by micro-CT and lung function tests.
• * Crucially, AAV6.2 vectors, unlike Ad5 vectors, did not elicit measurable inflammation, minimizing interference with experimental outcomes.

Conclusions:

• * Adeno-associated virus (AAV) variant 6.2 is proposed as an optimal vector for gene delivery to the lungs in mice.
• * This vector system overcomes common limitations associated with viral vector use in vivo, particularly regarding immunogenicity.
• * AAV6.2 facilitates the development of robust and reliable mouse models for studying pulmonary diseases and for preclinical drug testing.