An ex vivo model for gene therapy of hemophilia B using cultured human oral mucosal epithelium

Human oral mucosal cells are important target tissues for regenetic engineering and are sources of epithelial sheets. In this study, we examine the possibility of mucosal epithelial sheet as a target tissue for gene therapy. Human oral mucosal cells were transduced with a retroviral vector carrying human factor IX gene and constructed epithelium after G418 selection with 3T3 cells in vitro. The cultured oral mucosal epithelium membrane was then grafted onto immunodeficient mice. Between 0.6 and 1.8 ng of human factor IX per milliliter was found in mouse plasma, and the production was continued for 23 days in vivo. These results demonstrate a model of ex vivo gene therapy for hemophilia B using gene-modified oral mucosal epithelium.