Figure 2.

Mechanisms of tumor cell recognition by T cells. In traditional CTL cell therapy, the TCR recognizes tumor antigen peptides presented by MHC molecules on the tumor cells' surface through the TCR-CD3 complex, activates with the assistance of co-stimulation molecules and releases cytotoxic substances to kill tumor cells. By contrast, CAR-T is able to recognize the antigen of tumor cells through the scFv; this recognition is not restricted by MHC molecules, which has significant advantages over the traditional CTL cell therapy. CTL, cytotoxic T lymphocyte; TCR, T cell receptor; scFv, single chain fragment variable; MHC, major histocompatibility complex; CAR-T, chimeric antigen receptor T-cell.