In vitro induction of anterior gradient-2-specific cytotoxic T lymphocytes by dendritic cells transduced with recombinant adenoviruses as a potential therapy for colorectal cancer

Anterior gradient-2 (AGR2) promotes tumor growth, cell migration, and cellular transformation, and is one of the specific mRNA markers for circulating tumor cells in patients with gastrointestinal cancer. We investigated the feasibility of AGR2 as a potent antigen for tumor immunotherapy against colorectal cancer (CRC) cells using dendritic cells (DCs) transduced with a recombinant adenovirus harboring the AGR2 gene (AdAGR2). DCs transduced with a recombinant adenovirus encoding the AGR2 gene (AdAGR2/DCs) were characterized. These genetically-modified DCs expressed AGR2 mRNA as well as AGR2 protein at a multiplicity of infection of 1,000 without any significant alterations in DC viability and cytokine secretion (IL-10 and IL-12p70) compared with unmodified DCs as a control. In addition, AdAGR2 transduction did not impair DC maturation, but enhanced expression of HLA-DR, CD80, and CD86. AdAGR2/DCs augmented the number of IFN-gamma-secreting T-cells and elicited potent AGR2-specific cytotoxic T lymphocytes capable of lysing AGR2-expressing CRC cell lines. These results suggest that AGR2 act as a potentially important antigen for immunotherapy against CRC in clinical applications.