CD23-bound IgE augments and dominates recall responses through human naive B cells

J Immunol. 2011 Jan 15;186(2):1060-7. doi: 10.4049/jimmunol.1002709. Epub 2010 Dec 15.

Abstract

Human peripheral blood BCRμ(+) B cells express high levels of CD23 and circulate preloaded with IgE. The Ag specificity of CD23-bound IgE presumably differs from the BCR and likely reflects the Ag-specific mix of free serum IgE. CD23-bound IgE is thought to enhance B cell Ag presentation to T cells raising the question of how a B cell might respond when presented with a broad mix of Ags and CD23-bound IgE specificities. We recently reported that an increase in CD23(+) B cells is associated with the development of resistance to schistosomiasis, highlighting the potential importance of CD23-bound IgE in mediating immunity. We sought to determine the relationship between BCR and CD23-bound IgE-mediated B cell activation in the context of schistosomiasis. We found that crude schistosome Ags downregulate basal B cell activation levels in individuals hyperexposed to infectious worms. Schistosome-specific IgE from resistant, occupationally exposed Kenyans recovered responses of B cells to schistosome Ag. Furthermore, cross-linking of CD23 overrode intracellular signals mediated via the BCR, illustrating its critical and dominating role in B cell activation. These results suggest that CD23-bound IgE augments and dominates recall responses through naive B cells.

Publication types

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

MeSH terms

  • Animals
  • Antigen Presentation / immunology
  • Antigens, Helminth / immunology
  • Antigens, Helminth / metabolism
  • B-Lymphocyte Subsets / cytology
  • B-Lymphocyte Subsets / immunology*
  • B-Lymphocyte Subsets / metabolism
  • Binding Sites, Antibody
  • Cell Line, Tumor
  • Humans
  • Immunity, Innate / genetics
  • Immunity, Innate / immunology*
  • Immunoglobulin E / metabolism*
  • Immunoglobulin E / physiology
  • Immunologic Memory / genetics
  • Intracellular Fluid / immunology
  • Intracellular Fluid / parasitology
  • Lymphocyte Activation / immunology*
  • Mice
  • Mice, 129 Strain
  • Mice, Inbred NZB
  • Protein Binding / immunology
  • Receptors, IgE / biosynthesis
  • Receptors, IgE / metabolism
  • Receptors, IgE / physiology*
  • Resting Phase, Cell Cycle / immunology*
  • Schistosomiasis mansoni / immunology*
  • Schistosomiasis mansoni / metabolism
  • Schistosomiasis mansoni / prevention & control

Substances

  • Antigens, Helminth
  • Receptors, IgE
  • Immunoglobulin E