title: Enteroantigen (eAg)-binding B lymphocytes in the mouse - phenotype, distribution, function and eAg-specific antibody secretion.
abstract: Studies reporting beneficial effects of B lymphocytes in autoimmune diseases have been accumulating and a regulatory role for certain B cell subsets is hence getting more and more recognition. Recently, B cells were shown to exhibit a regulatory effect in a T cell transfer model of colitis. Here, B cells exposed to enteroantigen (eAg) ex vivo abrogated the colitogenic effect if co-transplanted with Treg-depleted (CD4+CD25-) T cells into severe combined immune deficiency (SCID) mice. These data may imply a role for B cells that bind eAg (eAg+ B cells) in the immunopathology of colitis. Here, we report the detection of a subset of eAg+ B cells, including both B2 and B1 lineages, and show that these cells are present in all peripheral lymphoid organs of the mouse including the peritoneal cavity. eAg+ B cells are far more efficient as eAg-presenting cells than unfractionated splenocytes or eAg- B cells in causing proliferation of eAg-specific T cells. In comparison with eAg- B cells, eAg+ B cells secrete a significant amount of IL-10 in vitro, suggesting an anti-inflammatory potential. Compared with wild-type B cells, B cell receptor (BCR) transgenic, hen egg lysozyme-specific B cells show inferior eAg binding and T cell stimulatory activity suggesting involvement of the BCR in eAg binding and processing. After activation of CD19(+) B cells by eAg and hybridization with hypoxanthine-aminopterin-thymidine (HAT) sensitive ×63 lymphoma cells followed by cloning at limiting dilution conditions, around 10% of the hybridoma cells secrete eAg-specific antibodies.
authors.affiliation: Laboratory of Experimental Immunology, Department of International Health, Immunology and Microbiology, The Panum Institute, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Freja Albjerg
authors.initials: FA
authors.lastname: Venning
authors.forename: Mette Louise
authors.initials: ML
authors.lastname: Trempenau
authors.forename: Esben
authors.initials: E
authors.lastname: Schmidt
authors.forename: Mogens Helweg
authors.initials: MH
authors.lastname: Claesson
mesh_terms: D000630:Aminopterin; D000818:Animals; D000906:Antibodies / Q000276:immunology; D000938:Antigen-Presenting Cells / Q000276:immunology; D018941:Antigens, CD19 / Q000276:immunology*; D000971:Antineoplastic Combined Chemotherapy Protocols; D001402:B-Lymphocytes / Q000276:immunology* / Q000637:transplantation; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000473:pathology / Q000637:transplantation; D049109:Cell Proliferation; D002478:Cells, Cultured; D003092:Colitis / Q000276:immunology*; D005260:Female; D019271:Hypoxanthine; D016753:Interleukin-10 / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D016513:Mice, SCID; D011947:Receptors, Antigen, B-Cell / Q000235:genetics; D013936:Thymidine
chemical_list: D000906:Antibodies; D018941:Antigens, CD19; C556062:IL10 protein, mouse; D011947:Receptors, Antigen, B-Cell; D016753:Interleukin-10; D019271:Hypoxanthine; D000630:Aminopterin; D013936:Thymidine
keywords: B cells; antibodies; cytokines; spleen and lymph nodes