title: Antigen-specific immunoglobulin E+ B cells are preferentially localized within germinal centres.
abstract: Allergen-specific immunoglobulin E (IgE) mediates immediate-type hypersensitivity reactions and plays a central role in allergic diseases. Although antigen-driven B-cell maturation and isotype switching occur within germinal centres (GCs), the role of GCs in IgE production is poorly understood. In view of this, we investigated the development of IgE-expressing cells within GCs in response to an extensively characterized antigen, 2-phenyloxazolone (phOx). The phOx-specific IgE-expressing cells localized within GCs 7 days after immunization, and peaked in number on day 11. Surprisingly, very few IgE-positive cells were found in the T-cell areas of the lymph node. Flow cytometric studies confirmed that IgE was expressed by B cells and was not the result of trapping by follicular dendritic cells. The specificity of the antibody response was confirmed by microdissection and reverse transcription-polymerase chain reaction using phOx-specific IgE primers. IgE-positive cells were primarily found within GCs while, in contrast, many IgG1-positive cells could also be detected outside GCs in the T-cell areas. Taken together, these data highlight the importance of GCs in the production of antigen-specific IgE antibody.
authors.affiliation: Department of Pathology and Laboratory Medicine, Geffen School of Medicine at University of California Los Angeles, Los Angeles, CA 90095, USA.
authors.forename: Kathleen A
authors.initials: KA
authors.lastname: Kelly
authors.forename: Anthony W
authors.initials: AW
authors.lastname: Butch
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D018985:Epitopes, B-Lymphocyte / Q000276:immunology; D005260:Female; D005786:Gene Expression Regulation / Q000276:immunology; D018858:Germinal Center / Q000276:immunology*; D006241:Haptens / Q000276:immunology; D007073:Immunoglobulin E / Q000096:biosynthesis* / Q000097:blood / Q000235:genetics; D007074:Immunoglobulin G / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D042282:Microdissection / Q000379:methods; D010081:Oxazolone / Q000031:analogs & derivatives / Q000276:immunology; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods
chemical_list: D018985:Epitopes, B-Lymphocyte; D006241:Haptens; D007074:Immunoglobulin G; D012333:RNA, Messenger; C018361:2-phenyloxazolone; D010081:Oxazolone; D007073:Immunoglobulin E