Lentiviral-mediated gene complementation to rescue pathogenic ABCA3 variants.

Area of Science:

• Pulmonary Medicine
• Genetics
• Cell Biology

Background:

• ATP-binding cassette subfamily A member 3 (ABCA3) protein is crucial for pulmonary surfactant production in alveolar type 2 (AT2) cells.
• ABCA3 deficiency, caused by pathogenic variants, leads to severe respiratory failure in neonates and children (chILD).
• Current treatments are limited to supportive care or lung transplantation.

Purpose of the Study:

• To investigate the therapeutic potential of ABCA3 gene complementation in a cellular model of ABCA3 deficiency.
• To evaluate the impact of different ABCA3 pathogenic variants on cellular function and response to gene therapy.

Main Methods:

• Utilized an ABCA3 knockout (KO) A549 human pulmonary epithelial cell line.
• Generated cell lines expressing wild-type (WT) or variant ABCA3 (L101P, E292V, E690K) via lentiviral delivery.
• Assessed lamellar body morphology, protein localization, cell proliferation, and NF-κB inflammatory signaling.

Main Results:

• WT ABCA3 expression partially restored AT2 cell characteristics, including localization to LAMP3+ vesicles and lamellar body-like structures.
• Gene complementation ameliorated aberrant NF-κB signaling in cells with type 2 ABCA3 variants (E292V, E690K).
• The L101P variant (type 1) and ABCA3 KO lines did not show significant improvement in inflammatory signaling.

Conclusions:

• ABCA3 gene complementation demonstrates therapeutic potential for ABCA3 deficiency.
• The efficacy of gene therapy may depend on the specific type of ABCA3 pathogenic variant.
• Understanding variant-specific effects is crucial for developing targeted genetic therapies for chILD.