Identification of a Mouse Anti-Rat IgE Monoclonal Antibody, 44.7b, Which Inhibits IgE Binding to RBL Cells

摘要

We have identified a monoclonal antibody specific for rat IgE, 44.7b, which blocks binding of rat IgE to the mast cell-like line RBL. Other monoclonal anti-rat IgE antibodies (MARE1 and B5) did not inhibit IgE binding to these cells. Furthermore, 44.7b did not react with IgE previously bound to these cells. These results indicate that 44.7b binds to an epitope on the IgE molecule which is within the binding site of the mast cell IgE Fc receptor (FcERI). The 44.7b monoclonal antibody did recognize IgE bound to a B lymphocyte cell line indicating that mast cell and B lymphocyte FcERs recognize different regions of the IgE molecule.