This article confirms the susceptibility of osteoblastic cells to adenoviral transduction. Osteoblasts were harvested from human cancellous bone. Cells were transduced, using various amounts of adenoviral vectors carrying the cDNA encoding interleukin-1 receptor antagonist (IL-1Ra), or the marker genes β-galactosidase and luciferase. Expression of the transgenes and the biological activity of IL-1Ra produced by gene transfer were measured quantitatively in a time-course by ELISA. The rate of transduction was 100% after exposure to 1 x 107 infective particles of adeno-LacZ. No expression of IL-1 Ra was seen after transduction with adeno-IL-1Ra at titers of 1x104 and less. However, after transduction at titers of 1 x107, infective particles cells expressed IL-1Ra consistently for 72 days, with levels up to 1 μg IL-1Ra/1 x 106 cells/48 hours. None of the control samples expressed detectable levels of IL-1Ra. The biological activity of the transgenic IL-1Ra was demonstrated by its ability to suppress successfully IL-1-induced nitric oxide synthesis by rabbit articular chondrocytes. After transduction with 1 x107 infective particles of the adeno-luciferase vector, up to 81,000 Units transgenic luciferase/x 106 osteoblastic cells were measured 2 days after gene transfer. Our results show that adenovirus transduces osteoblastic cells at a high rate in vitro.
ASJC Scopus subject areas
- Orthopedics and Sports Medicine