Epitope analysis and primary structures of variable regions of anti-human FcepsilonRI monoclonal antibodies, and expression of the chimeric antibodies fused with human constant regions

Biosci Biotechnol Biochem. 2000 Sep;64(9):1856-67. doi: 10.1271/bbb.64.1856.


The structural analysis of monoclonal antibodies (mAbs) against the alpha subunit of the high affinity IgE receptor (FcepsilonRIalpha) is an alternative approach to obtaining information for the design of inhibitors that will block complementary interaction between IgE and FcepsilonRIalpha and to analyzing the various biological effects induced by anti-FcepsilonRIalpha autoantibodies in chronic urticaria. In this study, epitopes for mouse anti-human FcepsilonRIalpha mAbs and primary structures of variable regions of the mAbs were analyzed. Three mAbs inhibitory for IgE-binding reacted to the deletion mutants of FcepsilonRIalpha containing the whole second immunoglobulin-like domain as well as IgE did. On the other hand, two uninhibitory mAbs reacted to those containing the whole first immunoglobulin-like domain. The cDNAs for variable regions of the five mAbs were cloned and sequenced. Two inhibitory mouse/human chimeric antibodies were expressed in COS7 cells and bound to Chinese hamster ovary transfectant cells expressing FcepsilonRI (CHO/alphabetagamma), and these inhibited the binding of IgE to CHO/alphabetagamma cells.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antibodies, Monoclonal / chemistry*
  • Antibodies, Monoclonal / genetics
  • Base Sequence
  • CHO Cells
  • COS Cells
  • Cloning, Molecular
  • Cricetinae
  • Epitopes / analysis
  • Escherichia coli
  • Flow Cytometry
  • Genes, Immunoglobulin*
  • Humans
  • Immunoglobulin Constant Regions / chemistry*
  • Immunoglobulin Constant Regions / genetics
  • Immunoglobulin E / immunology
  • Immunoglobulin Variable Region / chemistry*
  • Immunoglobulin Variable Region / genetics
  • Mice
  • Molecular Sequence Data
  • Mutagenesis
  • Protein Subunits
  • Rabbits
  • Receptors, IgE / immunology*
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / immunology
  • Recombinant Proteins / immunology
  • Sequence Alignment
  • Sequence Deletion
  • Sequence Homology, Amino Acid
  • Sequence Homology, Nucleic Acid
  • Transfection


  • Antibodies, Monoclonal
  • Epitopes
  • Immunoglobulin Constant Regions
  • Immunoglobulin Variable Region
  • Protein Subunits
  • Receptors, IgE
  • Recombinant Fusion Proteins
  • Recombinant Proteins
  • Immunoglobulin E