scFv(CD38)-OX40-CD3zeta CAR-T Lentivirus

The CAR structure consists of a single-chain antibody (scFv), a hinge region, a transmembrane domain, and an intracellular signal peptide. Binding to target antigens expressed on the cell surface triggers CAR-T cell activation independent of major histocompatibility complex (MHC) receptors. A single-chain fragment variable (scFv) is the single-chain variable region of a monoclonal antibody, consisting of a light chain variable region (VL) and a heavy chain variable region (VH), connected by a linker. Its primary function is to recognize tumor-associated antigens (TAAs).

The hinge region, located between the scFv and the transmembrane domain, is composed of immunoglobulin sequences such as CD8α and TCRβ. Its ability to deform and expand allows the heavy and light chains of the scFv to fold freely, creating space for the extracellular antigen-binding domain to approach the antigen. The transmembrane domain, composed of homologous or heterologous dimeric membrane proteins such as CD4, CD7, CD8, CD28, and CD3ζ, connects the extracellular and intracellular structures, ensuring the localization and stable expression of the CAR on the T cell membrane surface. The intracellular signal peptide region typically consists of costimulatory molecules (CM) and immunoreceptor tyrosine-based activating motifs (ITAMs), typically TCR/CD3ζ and FcεRIγ. When the extracellular domain binds to the antigen it recognizes, it transmits a T cell receptor (TCR)-like activation signal into the cell.