The 1D3 monoclonal antibody reacts with mouse CD19, a B cell-specific 95 kDa transmembrane glycoprotein of the immunoglobulin superfamily. CD19 contains two extracellular immunoglobulin-like domains and an extensive cytoplasmic tail. It functions as a positive regulator of B-cell receptor signaling in conjunction with CD21 and CD81. CD19 is highly expressed in most lymphomas and leukemias including some early B-cell malignancies that do not express CD20. For these reasons CD19 is quickly becoming an attractive alternative target for the immunotherapy of lymphoproliferative disorders. The 1D3 antibody has been reported to deplete B cells however, B cell depletion often requires treatment with a combination of 1D3, anti-mouse B220 (clone
RA3.3A1/6.1), anti-mouse CD22 (clone Cy34.1), and anti-rat kappa light chain (clone MAR 18.5) antibodies. Please see the provided references for protocol details.