Immunotherapy for colorectal cancer

Figure 2 Dendritic cell vaccines. Dendritic cells (DCs) are loaded with antigens, which are taken up and degraded into peptide fragments by antigen-presenting cells such as immature DCs. DCs process tumor-derived peptides and major histocompatibility complex (MHC) class I peptides derived from DCs. They form MHC class I-peptide complexes in the endoplasmic reticulum, which are then transported to the surface of the 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. CD8+ T cells become cytotoxic T lymphocytes (CTLs), which destroy cancer cells through effector molecules such as perforin and granzyme B. TCR: T cell receptor.