Figure 1.

Schematic representation of therapeutic vaccination using a peptide vaccine in a patient with tongue cancer. (1) Injection of the vaccine subcutaneously containing one or more peptides associated with tumor cells. Vaccine compounds are phagocyted by locally present dendritic cells. After migration of dendritic cells into lymph nodes, stimulation of CD4+ (2) and CD8+ (3) T lymphocytes by recognition of the antigens (formed from the vaccine) through interaction between the T cell receptor and the corresponding major histocompatibility complex. CD4+ effector T-lymphocytes produce surface proteins and cytokines for the activation of B lymphocytes, dendritic cells, and macrophages. They are also involved in the production of memory T cells. (4) Then, effector T-lymphocytes migrate through the blood vessels to the tumor. (5) Increased lymphocyte infiltration and inflammation within the cancerous tissue. (6) Tumor antigen recognition by cytotoxic CD8+ T lymphocytes via major histocompatibility complex type I. Activation of cytolytic compounds (as granzymes and perforin) to kill the cancer cells. Note the probable synergistic effect of immune checkpoint inhibitors and therapeutic vaccines.