Influence of short-term adenoviral vector and prolonged lentiviral vector mediated bone morphogenetic protein-2 expression on the quality of bone repair in a rat femoral defect model

• Published in: Bone (New York, N.Y.) N.Y.), 2008-05, Vol.42 (5), p.921-931
• Main Authors: Virk, Mandeep Singh, Conduah, Augustine, Park, Sang-Hyun, Liu, Nancy, Sugiyama, Osamu, Cuomo, Anna, Kang, Christine, Lieberman, Jay R
• Format: Article
• Language: English
• Subjects: Adenoviral vector; Adenoviridae - genetics; Adenovirus; Animals; Biological and medical sciences; Bioluminescent imaging; Biomechanical Phenomena; Bone Marrow Cells - metabolism; Bone Marrow Transplantation; Bone morphogenetic protein; Bone Morphogenetic Protein 2; Bone Morphogenetic Proteins - genetics; Bone Morphogenetic Proteins - metabolism; Bone repair; Elasticity; Ex vivo regional gene therapy; Femoral Fractures - pathology; Femoral Fractures - physiopathology; Femoral Fractures - therapy; Fracture Healing; Fundamental and applied biological sciences. Psychology; Genetic Therapy - methods; Genetic Vectors - genetics; Intercellular Signaling Peptides and Proteins - genetics; Intercellular Signaling Peptides and Proteins - metabolism; Lentiviral vector; Lentivirus; Lentivirus - genetics; Luciferases - genetics; Luciferases - metabolism; Luminescent Measurements; Male; Orthopedics; Rats; Rats, Inbred Lew; Recombinant Proteins - genetics; Recombinant Proteins - metabolism; Transfection; Transforming Growth Factor beta - genetics; Transforming Growth Factor beta - metabolism; Vertebrates: anatomy and physiology, studies on body, several organs or systems
• ISSN: 8756-3282; 1873-2763
• DOI: 10.1016/j.bone.2007.12.216

Abstract The objective of this study was to compare the efficacy of adenoviral and lentiviral regional gene therapy in a rat critical sized femoral defect model. The healing rates and quality of bone repair of femoral defects treated with syngeneic rat bone marrow cells (RBMCs) transduced with either lentiviral vector (Group I) or adenoviral vector (Group II) expressing bone morphogenetic protein-2 (BMP-2) gene were assessed. RBMCs transduced with the adenoviral vectors produced more than 3 times greater ( p < 0.001) BMP-2 when compared to RBMCs transduced with lentiviral vectors in an in vitro evaluation. Serial bioluminescent imaging demonstrated short duration luciferase expression (less than 3 weeks) in defects treated with RBMCs co-transduced with two adenoviral vectors (Group IV; adenovirus expressing BMP-2 and luciferase [Ad-BMP-2 + Ad-Luc]). In contrast, the luciferase signal was present for 8 weeks in defects treated with RBMCs co-transduced with two lentiviral vectors (Group III; lentivirus expressing BMP-2 and luciferase gene [LV-BMP-2 + LV-Luc]). There were no significant differences with respect to the radiological healing rates ( p = 0.12) in defects treated with lentiviral versus adenoviral mediated BMP-2 gene transfer. Biomechanical testing of healed Group I femoral specimens demonstrated significantly higher energy to failure ( p < 0.05) when compared to Group II defects. Micro CT analysis revealed higher bone volume/tissue volume fraction ( p = 0.04) in Group I defects when compared to Group II defects. In conclusion, prolonged BMP-2 expression associated with lentiviral mediated gene transfer demonstrated a trend towards superior quality of bone repair when compared to adenoviral mediated transfer of BMP-2. These results suggest that the bone repair associated with regional gene therapy is influenced not just by the amount of protein expression but also by duration of protein production. This observation needs validation in a more biologically challenging environment where differences in healing rates and quality of bone repair are more likely to be significantly different.