scFv(CD20)-CD28-41BB-CD3zeta CAR-T Lentivirus

CAR-T therapy involves genetically modifying T cell receptors (TCRs) with immunoglobulin (Ig) antigen-binding domains through gene cloning. This transfers genetic material carrying specific antigen recognition structures and T cell activation signals into T cells, enabling them to directly bind to specific antigens on the surface of tumor cells and activate them. After CAR recognizes tumor antigens, it activates T cell immune pathways, upregulating the expression of related genes and secreting substances such as granzymes and perforins, which directly mediate tumor cell lysis. Simultaneously, it secretes inflammatory factors such as granulocyte macrophage colony-stimulating factor (GM-CSF) and interferon-γ (IFNγ), recruiting innate immune cells such as macrophages to respond and kill tumor tissue, thereby treating cancer.

CARs are primarily composed of a single-chain Fv (scFv) segment that recognizes tumor-specific antigens, a hinge region and transmembrane domains, a costimulatory domain, and a CD3ζ domain. The development of CAR-T cells from the first generation to the current fourth generation has taken 30 years, primarily through the introduction of CAR-encoding genes into T cells. Third-generation CAR-T cells are constructed by adding a co-stimulatory molecule fragment to the second-generation CAR-T cells. These co-stimulatory molecules can be the classic CD28 and 4-1BB, or they can be composed of classic signaling molecules combined with OX40, ICOS, CD27, CD40-MyD88, and others, i.e., a tandem ScFv, two co-stimulatory molecules, and a CD37 domain. In 2009, June''s team showed that the addition of the two co-stimulatory molecules, CD28 and 4-1BB, to the CAR resulted in CAR-T cells with higher cytokine secretion levels and stronger proliferation activity. Researchers refer to these CAR-T cells containing two or more co-stimulatory molecules as third-generation CAR-T cells.