B4 - Heart, Lung, and Kidney Diseases
1582: Enhancing Airway Transduction Using AAV Equipped with Advanced Barcoding Methods for CF Gene Therapy
Type: Poster Session
Poster Board Number: 1582
Presentation Details
Session Title: Friday Posters: Heart, Lung, and Kidney Diseases
Approximately ~10% of people with CF do not benefit from current CFTR modulators, including those with nonsense or splicing mutations and those intolerant of the medications. This motivates our investigations into genetic therapies including gene addition and gene editing. A key limitation to applying these and other emerging technologies to CF is effective therapeutic delivery. Adeno-associated virus (AAV) is a broadly useful vector for delivery to many cell types and is safe unless delivered at very high doses. Because of its persistence as an episome, expression lasts for months or years in slowly dividing cells. While past CF clinical trials using AAV2 were unsuccessful, many of the contributing limitations have been identified including poor transduction efficiency and inappropriate expression cassette design. Here, we address the inefficiency of current AAVs by taking advantage of an AAV library screen. Using advanced AAV barcoding methods and screening in multiple large mammalian species, we identified capsid variants that can transduce target cell types at doses 1 to 2 logs lower than currently available capsids. Additionally, libraries of capsids from multiple serotypes were screened in primary air-liquid interface cultures of human airway epithelia (HAE) isolated from CF and non-CF individuals. One consistently enriched variant, BLD034, shows significantly enhanced transduction properties compared with the benchmark AAV2.5T capsid in HAE, even in the absence of the proteosome inhibitor doxorubicin (Dox). To test the transduction ability of BLD034 in a relevant airway model, HAE were transduced from the apical surface with AAV2.5T and AAV-BLD034 overnight in the presence or absence of Dox. By 21 days post-transduction, GFP expression in HAE transduced with BLD034 was robust relative to AAV2.5T in the absence of Dox. In the presence of Dox, these results were further amplified. Ongoing experiments are testing minimal effective dose and complementing CFTR in CF HAE. AAV capsids designed with advanced barcoding techniques provide opportunities for improved potency and may omit the need for concomitant proteasome modulation in airway gene therapy applications.
Plain Language Summary
A major hurdle for genetic lung diseases such as cystic fibrosis is delivery to target cells in the airway. Here we use an advanced barcoding approach to modify the AAV capsid to improve delivery to the airways. Additionally, AAV delivery is enhanced by proteasome modulation. This new capsid generated, termed AAV-BLD034, improves transduction in the absence of a proteasome inhibitor relative to the leading airway-tropic capsid. Using this technology could decrease the therapeutic index necessary for gene therapy applications.
Ashley L. Cooney1, Yonghong Chen2, Brian Lewandowski2, Priyanka K. Newase1, Beverly L. Davidson2, Paul B. McCray1
1University of Iowa, Iowa City, IA,2Children's Hospital of Philadelphia, Philadelphia, PA"
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