The application provides a nanobody targeting human transmembrane activator and
calcium modulator and
cyclophilin interactor (TACI) and an application thereof, and the
antibody is derived from a llama
heavy chain antibody variable region. The anti-TACI single-domain
antibody NB38 can specifically bind to human TACI with high affinity, can recognize a recombinant TACI
protein, can also recognize a TACI with a natural conformation on a
cell surface, and can partially block a BAFF / APRIL
signal pathway. Based on the nanobody, the application constructs a
fusion protein, a
chimeric antigen receptor, an
effector cell expressing the
chimeric antigen receptor, and a double-specific
cell linker and other
genetically engineered forms. The nanobody can be further extended into a
drug coupling form. The product of the application can be used for mediating directional recognition and killing of TACI positive cells, and can be used as a supplement and expansion of BCMA
targeted therapy, and provides a new candidate technical scheme for
targeted therapy of
multiple myeloma and other TACI related diseases.