Figure 2. Tumor antigen synthesis, processing and presentation by an antigen-presenting cell after viral transduction and T-cell activation.
Viral vector expressing offers several advantages in generating antitumor immunity: (1) the contact of virus optimally activates APCs; (2) multiple altered peptide ligands are integrated into the epitope-optimized heteroclitic full length Ag, activating a broader spectrum of immune responses and facilitating epitope identification; (3) Ag synthesized inside APCs may undergo the same Ag processing and presentation pathway as that in tumor cells; and (4) the activated T cells will have better chance of recognizing tumor cells. Ag: Antigen; APC: Antigen-presenting cell; ER: Endoplasmic reticulum.