Definition

A preparation of autologous T lymphocytes that have been engineered to express a chimeric autoantibody receptor (CAAR) containing the autoantigen muscle, skeletal receptor tyrosine-protein kinase (MuSK; muscle-specific kinase) that is fused to the co-stimulatory domain of 4-1BB (CD137) and the T-cell receptor signaling domain of CD3zeta (CD3z), with potential immunomodulatory activity. Upon administration, the autologous MuSK-CD3z/4-1BB-expressing CAAR T cells MuSK-CAART specifically recognize and induce selective toxicity in aberrant B cells expressing MuSK autoantibodies. This inhibits the production of MuSK autoantibodies. MuSK is a transmembrane protein expressed on skeletal muscle cell membrane that plays an important role in the formation and maintenance of the neuromuscular junction. MuSK autoantibodies are produced and expressed by aberrant B cells in MuSK-associated myasthenia gravis.