scFv(CD33)-CD28-CD3zeta CAR-T Lentivirus

The use of chimeric antigen receptor (CAR) vectors to produce engineered T cells that can recognize tumor-associated antigens (also known as CAR T cells) has become a very promising tool for cancer treatment. In CAR T cell immunotherapy, T cells from patients (autologous) or healthy donors (allogeneic) are modified to express CAR. CAR receptors can target and recognize antigens on the surface of tumor cells, activating T cells to exert immune functions and help kill tumor cells.

The structure of CAR receptors consists of four main parts: (1) an extracellular antigen recognition domain composed of a single chain variable fragment (scFv) of an antibody with known specificity. The scFv facilitates antigen binding and consists of a light chain variable region fragment and a specific monoclonal antibody heavy chain fragment, both connected by a flexible peptide chain; (2) an extracellular hinge region or spacer that connects the scFv to the transmembrane domain of the CAR and provides flexibility and stability to the CAR structure; (3) the transmembrane domain that anchors the CAR to the plasma membrane, thereby linking the extracellular hinge region and antigen binding domain with the intracellular domain. It plays a key role in enhancing receptor expression and stability; (4) the intracellular signaling domain, which is usually derived from the CD3 zeta chain of the T cell receptor and contains the immunoreceptor tyrosine-based activation motif (ITAM). After antigen binding to the CAR, the ITAM is phosphorylated and activates downstream signaling, leading to subsequent T cell activation. In addition, the intracellular domain can also introduce one or more co-stimulatory domains (derived from CD28, CD137, etc.) in series with the CD3 zeta signaling domain to improve the efficiency of T cell proliferation and the persistence of activation.