The present disclosure relates to anti-TRBC1 antigen binding domainscharacterized by the sequences of the variablechains. The CDRs sequences of the variable chains are : (VH CDR1) GYTFT, (VHCDR2) NPYNDDIQS, (VH CDR3)GAGYNFDGAYRFFDF; and (VL CDR1) RSSQRLVHSNGNTYL, (VL CDR2) RVSNRFP, (VL CDR3)SQSTHVPYT. The claimedhumanized antibodies derive from the murine JOVI antibody. Uses in cancertherapy.