Green fluorescent protein-adenoviral construct as a model for transient gene therapy for human cultured keratinocytes in an athymic mouse model

Background: The goal of gene therapy for cultured keratinocyte grafts is to accelerate growth and wound healing following engraftment without producing long-term complications from the delivered gene. We studied a Green Fluorescent Protein-Adenoviral construct (GFP-ADV) to determine the characteristics of gene expression in human cultured keratinocyte grafts. Methods: Twelve GFP-ADV grafts and twelve control grafts were transplanted to the flanks of 24 athymic mice. Mouse flanks were monitored with fluorescence-filtered microscopy and, on Day 21, were sectioned and stained with antihuman MHC Class I with H&E counterstaining. Real-time PCR was performed on graft biopsies for adenoviral DNA. Results: Fluorescence decreased from Days 3 to 5 resulting in no difference between GFP-ADV and control grafts from days 5 to 10. All grafts were positive for human MHC Class I with an epithelial architecture by H&E. Day 21 GFP-ADV grafts were negative for adenoviral DNA. Conclusion:. The delivered gene was transiently expressed without the persistence of viral DNA, demonstrating the potential of adenoviral gene delivery for the improvement of wound healing without long-term adverse effects to the graft.