Visions of the Hereafter: Releasing the Brakes of the Immune System by Checkpoint Inhibition Immunotherapy

Activation and control of the immune system is regulated by costimulatory molecules as well as by checkpoint inhibitors. Checkpoints are essential in maintaining self-tolerance and minimizing collateral damage by modulating the immune response. Evasion of the immune system, one of the hallmarks of cancer, has been found to include interference with checkpoints by tumor cells as one of the evasive mechanisms. Tumor cells express molecules that when bound to their respective ligand or receptor, send out inhibitory signals that block T-cell activation. Specific antibodies have been engineered against these Immunosuppressive molecules (mainly CTLA-4 and PD-1) such that the T-cells can exert cytotoxic anti-tumor effects. These