Lentiviral-mediated gene complementation rescues pathogenic ABCA3 variants.

Area of Science:

• Pulmonary Medicine
• Molecular Genetics
• Cell Biology

Background:

• ABCA3 protein is crucial for pulmonary surfactant production in alveolar type 2 cells.
• ABCA3 deficiency, caused by pathogenic variants, leads to severe respiratory failure in neonates and children.
• Current treatments for ABCA3 deficiency are limited to supportive care or lung transplantation.

Purpose of the Study:

• To investigate the potential of gene addition therapy for ABCA3 deficiency.
• To evaluate the functional rescue of different ABCA3 pathogenic variants using gene complementation.
• To assess the impact of gene addition on cellular morphology, proliferation, and inflammatory signaling.

Main Methods:

• Utilized a human pulmonary epithelial cell line (A549) with a silenced ABCA3 locus (ABCA3^KO).
• Generated cell lines expressing wild-type or variant ABCA3 cDNA (L101P, E292V, E690K) via lentiviral delivery.
• Assessed rescue of ABCA3 localization, lamellar body morphology, cell proliferation, and NF-κB signaling.

Main Results:

• Lentiviral-mediated ABCA3 gene delivery partially rescued localization to LAMP3+ vesicles, lamellar body-like structures, and cell proliferation.
• Complementation ameliorated aberrant NF-κB inflammatory signaling in type 2 ABCA3 variants (E292V, E690K), but not in type 1 (L101P) or knockout lines.
• Observed differences in therapeutic response based on the type of ABCA3 pathogenic variant.

Conclusions:

• Gene addition holds therapeutic potential for ABCA3 deficiency, offering a promising alternative to current treatments.
• The efficacy of gene therapy for ABCA3 deficiency may depend on the specific pathogenic variant.
• Further research is warranted to optimize gene addition strategies for different ABCA3 mutations and clinical outcomes.