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

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.

• Authors: Daniel Onguru, YanMei Liang, Jennifer Elliot, Pauline Mwinzi, Lisa Ganley-Leal
• Journal: Infection and immunity (Infect Immun) Vol. 79 Issue 9 Pg. 3770-7 (Sep 2011) ISSN: 1098-5522 [Electronic] United States
• PMID: 21708991 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

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

Topics

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