METHODS AND MATERIALS FOR MODULATION OF THE IMMUNOSUPPRESSIVE ACTIVITY AND TOXICITY OF MONOCLONAL ANTIBODIES

摘要

The binding specificity of the murine OKT3 has been transferred into a human antibody framework in order to reduce its immunogenicity. This "humanized" anti-CD3 mAb (gOKT3-5) was previously shown to retain, in vitro, all the properties of native OKT3, including T cell activation which has been correlated, in vivo, with the severe side-effects observed in transplant recipients after the first administration of the mAb. Disclosed is a single amino acid mutation from a leucine to a glutamic acid at position 235 in the Fc receptor (FcR) binding segment of the gOKT3-5 mAb to produce Glu-235 mAb. Also disclosed is an amino acid mutation from the contiguous phenylalanine at position 234 to a leucine (Leu-234).