title: CD23-bound IgE augments and dominates recall responses through human naive B cells.
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.
authors.affiliation: Section of Infectious Diseases, Department of Medicine, Boston University School of Medicine, Boston Medical Center, Boston, MA 02118, USA.
authors.forename: Qyana K
authors.initials: QK
authors.lastname: Griffith
authors.forename: YanMei
authors.initials: Y
authors.lastname: Liang
authors.forename: Daniel O
authors.initials: DO
authors.lastname: Onguru
authors.forename: Pauline N
authors.initials: PN
authors.lastname: Mwinzi
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Ganley-Leal
mesh_terms: D000818:Animals; D017951:Antigen Presentation / Q000276:immunology; D000947:Antigens, Helminth / Q000276:immunology / Q000378:metabolism; D016175:B-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D001666:Binding Sites, Antibody; D045744:Cell Line, Tumor; D006801:Humans; D007113:Immunity, Innate / Q000235:genetics / Q000276:immunology*; D007073:Immunoglobulin E / Q000378:metabolism* / Q000502:physiology; D007156:Immunologic Memory / Q000235:genetics; D007424:Intracellular Fluid / Q000276:immunology / Q000469:parasitology; D008213:Lymphocyte Activation / Q000276:immunology*; D051379:Mice; D057507:Mice, 129 Strain; D008814:Mice, Inbred NZB; D011485:Protein Binding / Q000276:immunology; D017455:Receptors, IgE / Q000096:biosynthesis / Q000378:metabolism / Q000502:physiology*; D016192:Resting Phase, Cell Cycle / Q000276:immunology*; D012555:Schistosomiasis mansoni / Q000276:immunology* / Q000378:metabolism / Q000517:prevention & control
chemical_list: D000947:Antigens, Helminth; D017455:Receptors, IgE; D007073:Immunoglobulin E