887. Bone Formation by Ex Vivo Gene Therapy Using Lentiviral Vector Expressing BMP-2 under the Control of the MLV Promoter

Objective: Bone morphogenetic protein-2 (BMP-2) is an osteoinductive growth factor that can induce bone formation in vivo. Bone marrow stromal cells (BMSCs) are attractive targets for ex vivo gene therapy, and have been reported to differentiate into osteoblasts in the presence of BMP-2. Although we previously demonstrated that ex vivo gene therapy using an adenovirus expressing the BMP-2 induced bone formation successfully in animal models, the transient protein production may not be of adequate duration to heal large bone defects. Lentivirus is known to infect both dividing and non-dividing cells and induce long-term transgene expression. The objective of this study is to examine the potential of ex vivo gene therapy to enhance bone repair using a lentiviral vector.