Chimeric antigen receptors (CARs, also known as chimeric immune-receptors, chimeric T cell receptors or artificial T cell receptors) are engineered receptors that express on the surface of T cells and instruct the immune cell to specifically target cancer cells. The receptors are called chimeric because they are fused of parts from different sources. CAR-T cells are a new type of treatment that uses living T cells that have beentransduced.
The basic principle of CAR-T cell design involves recombinant receptors that combine antigen-binding and T-cell activating functions. The general premise of CAR-T cells is to artificially generate T-cells targeted to markers found on cancer cells. Scientists can remove T-cells from a person, genetically alter them, and put them back into the patient for them to attack the cancer cells.Once the T cell has been engineered to become a CAR-T cell, it act as a "living drug". CAR-T cells create a link between an extracellular ligand recognition domain to an intracellular signaling molecule which in turn activates T cells. The extracellular ligand recognition domain is usually a single-chain variable fragment (scFv). The specificity and safety of CAR-T cells are determined by the choice of molecule that is targeted.