Anti-CepsilonmX antibodies capable of binding to human mIgE on B lymphocytes

摘要

The invention pertains to the generation and utility of antibodies that can bind effectively to CεmX domain on membrane-bound IgE (mIgE) expressed on the surface of human B lymphocytes. The CεmX domain of 52 amino acid residues, located between the CH4 domain and the C-terminal membrane-anchor peptide on human membrane-bound epsilon chain, had been suggested as an antigenic site for immunological targeting of B cells expressing mlgE. Previous reported monoclonal antibodies, including a20, which bind to RADWPGPP peptide at the C-terminal of CεmX, have now been found to bind poorly to mlgE on human B cells. We have discovered that only monoclonal antibodies specific for certain segments, such as GLAGGSAQSQRAPDRVL and HSGQQQGLPRAAGGSVPHPR, of CεmX can bind effectively to mlgE on human B cells and hence have the utility for targeting those B cells for the treatment of diseases mediated by IgE.