Although animal studies have shown that tumor antigen (TA)-pulsed dendritic cell (DC)-based vaccines can mediate antitumor effects in vivo, human clinical trials utilizing this strategy have thus far had only modest success. In an effort to improve the efficacy of tumor vaccines, numerous investigators have explored the genetic engineering of DC to impart cytokine or TA-expression capability on DC. These efforts have focused on enhancing TA presentation and as well as subsequent T-cell activation and expansion. This chapter reviews recent progress in studies aimed to potentiate the efficacy of DC-based vaccines by genetic engineering of DCs with cDNAs encoding immuno-stimulatory cytokine-genes or TAs.
Keywords: DC-based vaccines, tumor antigens, gene-silencing, GM-CSF, Immunological Microenvironment