Adenovirus-mediated transgene-engineered dendritic cell vaccine of cancer

Dendritic cells (DCs) are the most effective antigen presenting cells (APCs) to elicit both primary and secondary T-cell response that is critical for antitumor immunity and elimination of intracellular pathogens. Therefore, DCs pulsed ex vivo with antigens have the potential used as cell-based vaccines against tumors. Viral vectors derived from adenoviruses have been extensively used to pulse DCs ex vivo by delivering genes encoding immunomodulatory molecules and tumor antigens to DCs since these vectors are relatively safe, effective in inducing the maturation of DCs, and can accommodate large expression cassettes encoding antigens. One of the hurdles for gene delivery to DCs by adenovirus (Ad) vectors, however, is low transfection efficiency of DCs due to the paucity of Ad receptor on DCs. To overcome this obstacle, targeted Ad vectors have been made by modifying viral capsid proteins. These targeted Ad vectors not only enhance the gene delivery to DCs, but also allow in vivo gene delivery to DCs, thus avoiding ex vivo manipulation of DCs.