Apoptosis of malignant human B cells by ligation of CD20 with monoclonal antibodies

摘要: CD20 is a nonglycosylated 33 to 37 kD phosphoprotein involved in B-cell signaling that subserves important functions the regulation of proliferation and differentiation. In addition, this surface antigen has been shown recently be an effective target for immunotherapy malignancies using chimeric (mouse/human) or radiolabeled murine monoclonal anti-CD20 antibodies. report we show extensive crosslinking with antibodies (MoAbs) presence either goat anti-mouse IgG Fc receptor (FcR)-expressing cells directly inhibits proliferation, induces nuclear DNA fragmentation, leads cell death by apoptosis. The apoptotic effects these MoAbs can inhibited chelation extracellular intracellular Ca2+ EGTA Bapta AM, indicating anti-CD20–mediated apoptosis may related changes concentration. These findings suggest ligation vivo FcR-expressing initiate signal transduction events induce elevation [Ca2+]i lead malignant B cells, thereby contributing impressive tumor regressions observed mouse models clinical trials MoAbs.