Adenovirus-Mediated MUC1 gene transduction into human blood-derived dendritic cells

MUCI protein is widely expressed on various human cancer cells and has a specific highly glycosylated core structure with multiple tandem repeats, which may include an immunogenic peptide sequence. The potency of MUC1 protein to induce human histocompatibility leukocyte antigen-class I-restricted cytotoxic T-lymphocyte (CTL) induction remains to be fully clarified in human beings. In the current study, we made MUCI-expressing human dendritic cells (DCs) using recombinant adenovirus vector. Adenovirus vector plasmid containing human MUCI cDNA, pAdHM4-MUC1 was constructed using in vitro ligation with a shuttle vector, pHMCMV5. Adenovirus vector expressing MUCI was generated by the transfection of PacI-digested recombinant vector plasmid into 293 cells. Human blood DCs were obtained from 7-day culture of monocytes with recombinant human (rh) granulocyte-macrophage (GM) colony-stimulating factor (CSF) and (rh)interleukin (IL)-4. Then, I x 10 6 DCs were incubated with viral supernatant at a multiplicity of infection of 200 for 24 h in the presence of rhGM-CSF and rhlL-4. Flow cytometric analysis showed that 30% to 40% of the transduced DCs expressed MUCI protein; by contrast, nontransduced or transduced DCs with mock virus expressed only small amounts of MUC1 protein. Adenovirus-mediated MUCI gene transduction into DCs had no significant effect on DC surface marker expressions or functions such as mixed leukocyte reaction. Furthermore, MUCI-specific CD8 + CTLs could be induced from healthy donor blood lymphocytes using MUCI-expressing DCs as stimulators. These results suggested that MUCI gene-transduced DCs are a functional and potent tool for triggering a CTL response against MUC1 + cancer cells.