CD23b isoform expression in human schistosomiasis identifies a novel subset of activated B cells

Infect Immun. 2011 Sep;79(9):3770-7. doi: 10.1128/IAI.05094-11. Epub 2011 Jun 27.

Abstract

Resistance to schistosomiasis is associated with increased levels of serum parasite-specific IgE. IgE exerts its functions through its cellular receptors, FcεRI and FcεRII/CD23; however, its functional significance in humans requires further characterization. We previously reported that increased levels of CD23(+) B cells correlate with resistance to schistosomiasis in hyperexposed populations and sought to define their potential function and relationship with IgE. We found that CD23(+) B cells are a heterogeneous cell population with functional and phenotypic differences. Circulating CD23(+) B cells are uniquely activated in schistosomiasis and express the CD23b isoform and CXCR5, the homing receptor for lymphoid follicles. High CXCR5 expression by CD23(+) B cells was associated with the capacity to home to the cognate ligand CXCL13. CD23-bound IgE cross-linking increased surface expression of CXCR5, suggesting that CD23(+) B cells home directly into the lymphoid follicles upon antigen capture. As human schistosomiasis is an intravascular parasitic infection associated with a high antigenic burden in the blood, circulating CD23(+) B cells may play a role in the capture and shuttling of antigens directly to splenic follicles, highlighting a new role for circulating B cells. This function likely plays an important role in the development of protective immunity to infection with schistosomes.

Publication types

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

MeSH terms

  • Adult
  • Animals
  • B-Lymphocyte Subsets / immunology*
  • Cells, Cultured
  • Chemokine CXCL13 / metabolism
  • Flow Cytometry
  • Humans
  • Immunoglobulin E / blood
  • Immunoglobulin E / immunology
  • Lymphocyte Activation
  • Male
  • Middle Aged
  • Protein Isoforms / metabolism
  • Receptors, CXCR5 / biosynthesis
  • Receptors, CXCR5 / metabolism
  • Receptors, IgE / biosynthesis
  • Receptors, IgE / immunology*
  • Receptors, IgE / metabolism
  • Schistosoma mansoni / immunology*
  • Schistosomiasis mansoni / immunology*
  • Spleen / immunology

Substances

  • CXCL13 protein, human
  • CXCR5 protein, human
  • Chemokine CXCL13
  • Protein Isoforms
  • Receptors, CXCR5
  • Receptors, IgE
  • Immunoglobulin E