A detailed mathematical model predicts that serial engagement of IgE-Fc epsilon RI complexes can enhance Syk activation in mast cells

J Immunol. 2010 Sep 15;185(6):3268-76. doi: 10.4049/jimmunol.1000326. Epub 2010 Aug 23.


The term serial engagement was introduced to describe the ability of a single peptide, bound to a MHC molecule, to sequentially interact with TCRs within the contact region between a T cell and an APC. In addition to ligands on surfaces, soluble multivalent ligands can serially engage cell surface receptors with sites on the ligand, binding and dissociating from receptors many times before all ligand sites become free and the ligand leaves the surface. To evaluate the role of serial engagement in Syk activation, we use a detailed mathematical model of the initial signaling cascade that is triggered when FcepsilonRI is aggregated on mast cells by multivalent Ags. Although serial engagement is not required for mast cell signaling, it can influence the recruitment of Syk to the receptor and subsequent Syk phosphorylation. Simulating the response of mast cells to ligands that serially engage receptors at different rates shows that increasing the rate of serial engagement by increasing the rate of dissociation of the ligand-receptor bond decreases Syk phosphorylation. Increasing serial engagement by increasing the rate at which receptors are cross-linked (for example by increasing the forward rate constant for cross-linking or increasing the valence of the ligand) increases Syk phosphorylation. When serial engagement enhances Syk phosphorylation, it does so by partially reversing the effects of kinetic proofreading. Serial engagement rapidly returns receptors that have dissociated from aggregates to new aggregates before the receptors have fully returned to their basal state.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Binding Sites, Antibody / genetics
  • Cell Line, Tumor
  • Enzyme Activation / genetics
  • Enzyme Activation / immunology
  • Immunoglobulin E / chemistry
  • Immunoglobulin E / metabolism*
  • Immunoglobulin E / physiology
  • Immunoglobulin Fragments / chemistry
  • Immunoglobulin Fragments / metabolism*
  • Immunoglobulin Fragments / physiology
  • Intracellular Signaling Peptides and Proteins / metabolism*
  • Leukemia, Basophilic, Acute / enzymology
  • Leukemia, Basophilic, Acute / immunology
  • Ligands
  • Lymphocyte Activation / genetics
  • Lymphocyte Activation / immunology
  • Mast Cells / enzymology*
  • Mast Cells / immunology*
  • Mast Cells / metabolism
  • Models, Immunological*
  • Predictive Value of Tests
  • Protein Transport / genetics
  • Protein Transport / immunology
  • Protein-Tyrosine Kinases / metabolism*
  • Rats
  • Receptors, IgE / chemistry
  • Receptors, IgE / metabolism*
  • Receptors, IgE / physiology
  • Signal Transduction / genetics
  • Signal Transduction / immunology
  • Syk Kinase
  • Up-Regulation / genetics
  • Up-Regulation / immunology*


  • FCER1A protein, rat
  • Immunoglobulin Fragments
  • Intracellular Signaling Peptides and Proteins
  • Ligands
  • Receptors, IgE
  • Immunoglobulin E
  • Protein-Tyrosine Kinases
  • Syk Kinase
  • Syk protein, rat