Current Immunotherapeutic Approaches in Pancreatic Cancer

Figure 1

CTL induction by DCs. Antigens are taken up and degraded into peptide fragments by antigen-presenting cells, such as immature DCs. DCs process tumor-derived peptides and MHC class I peptides derived from DCs. They form MHC class I-peptide complexes, in the endoplasmic reticulum, which are transported to the surface of DCs and presented to CD8+ T cells. DCs also synthesize MHC class II peptides in the endoplasmic reticulum, which are transported to the cytoplasm where MHC class II-peptide complexes are assembled with tumor-derived peptides and presented to CD4+ T cells. The CD4+ T cells produce increased amounts of IL-2, which drives CD8+ T-cell proliferation. CD8+ T cells then become CTL, which can destroy cancer cells through effector molecules such as granzyme B and perforin.