Efficient Gene Transduction by RGB‐fiber Modified Recombinant Adenovirus into Dendritic Cells

Dendritic cells (DC) are important antigen‐presenting cells in the development of an anti‐tumor T cell response. To extend the range of current immuno/gene therapies, we tested luciferase‐expressing RGD‐adenovirus (Ad) (Ad5lucRGD)‐mediated transduction into DC. Phenotypically characterized DC were generated from peripheral blood CD14(+) cells by incubation with granulocyte‐macrophage colony‐stimulating factor, interleukin‐4 and tumor necrosis factor a. On the 7th day of culture, the cells became mature DC with a CD1a(+), CD11c(+), CD80(+), CD83(+), CD86(+), human leukocyte antigen (HLA)‐DR(+), CD14(−) phenotype. The expression of (α,β(3) integrin was enhanced on day 3 and returned to the basal level on day 7. We then compared the transduction efficiency of an AdSlucRGD system to that using conventional Ad, in cells harvested on days 1, 3 and 7 of culture. Luciferase activity was negligible in AdCMVLuc, but remarkable in cells processed with Ad5lucRGD. Activity was maximal in cells that had been cultured for 3 days. Recombinant Ad5 fiber knob protein blocked AdCMVLuc‐ and Ad5lucRGD‐mediated gene transduction by 90% and 20%, respectively. Surface markers and cytokine production were not affected by Ad5lucRGD‐mediated transduction.