The expression of murine B cell CD23, in vivo, is regulated by its ligand, IgE

Int Immunol. 1998 Sep;10(9):1377-84. doi: 10.1093/intimm/10.9.1377.


CD23, the low-affinity IgE receptor, is believed to participate in immune responses by mediating antigen capture for presentation by B cells and by shedding fragments with immunomodulatory properties. The number of CD23 molecules on B cells is increased during allergic responses and infection with helminths. This can be attributed in part to regulation of CD23 expression by cytokines, including IL-4. In addition, there is evidence that CD23 can be induced on cultured B cells by its ligand, IgE. In the current study we use IgE-deficient (IgE-/-) mice to establish the effects of IgE on CD23 expression by B cells in vivo, in the absence of allergic or parasitic stimuli. The spleens of IgE-/- and wild-type mice contained similar proportions of CD23+ B lymphocytes. However, cells from IgE-/- mice were found to have nearly 3-fold less CD23 on their surface. The mutant B cells had a corresponding defect in their ability to bind IgE. CD23 could be normally induced on IgE-/- B cells after culture with IL-4 or CD40 ligand, indicating that these cells had no inherent defect in CD23 biosynthesis. CD23 expression and IgE-binding capacity were both restored when splenocytes from IgE-/- mice were cultured in the presence of IgE. IgE-induced up-regulation of CD23 could be elicited in vivo as well. In IgE-/- mice, i.v. infusion of IgE corrected CD23 expression to wild-type levels. Our results demonstrate that IgE directly participates in CD23 regulation in vivo. This positive feedback loop may constitute a mechanism for the amplification of ongoing allergic responses.

Publication types

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

MeSH terms

  • Animals
  • B-Lymphocytes / metabolism*
  • Immunoglobulin E / deficiency
  • Immunoglobulin E / pharmacology
  • Immunoglobulin E / physiology*
  • Immunoglobulin Heavy Chains
  • Ligands
  • Mice
  • RNA, Messenger / metabolism
  • Receptors, IgE / biosynthesis*


  • Immunoglobulin Heavy Chains
  • Ligands
  • RNA, Messenger
  • Receptors, IgE
  • Immunoglobulin E