Adenoviral transduction of human osteoblastic cell cultures - A new perspective for gene therapy of bone diseases

This article confirms the susceptibility of osteoblastic cells to adenovira l transduction. Osteoblasts were harvested from human cancellous bone. Cell s were transduced, using various amounts of adenoviral vectors carrying the cDNA encoding interleukin-1 receptor antagonist (IL-1Ra), or the marker ge nes beta-galactosidase and luciferase. Expression of the transgenes and the biological activity of IL-1Ra produced by gene transfer were measured quan titatively in a timecourse by ELISA. The rate of transduction was 100% afte r exposure to 1 x 10(7) infective particles of adeno-LacZ. No expression of IL-1 Ra was seen after transduction with adeno-IL-1Ra at titers of 1 x 10( 4) and less. However, after transduction at titers of 1 x 10(7), infective particles cells expressed IL-1 Ha consistently for 72 days, with levels up to 1 mu g IL-1Ra/1 x 10(6) cells/48 hours. None of the control samples expr essed detectable levels of IL-1 Ha. The biological activity of the transgen ic IL-1 Ra was demonstrated by its ability to suppress successfully IL-1-in duced nitric oxide synthesis by rabbit articular chondrocytes. After transd uction with 1 x 10(7) infective particles of the adeno-luciferase vector, u p to 81,000 Units transgenic luciferase/x 10(6) osteoblastic cells were mea sured 2 days after gene transfer. Our results show that adenovirus transduc es osteoblastic cells at a high rate in vitro.