title: Induction of autoimmunity in a transgenic model of B cell receptor peripheral tolerance: changes in coreceptors and B cell receptor-induced tyrosine-phosphoproteins.
abstract: Abrogation of peripheral tolerance in transgenic mice that express a uniform B-cell receptor may create a powerful tool to examine the molecular mechanisms that underlie the autoimmune response in B cells. Here we report that processes that induce a systemic lupus erythematosus-like syndrome in normal mice, namely chronic graft vs host reaction, trigger systemic autoimmunity in a well-established transgenic mice model of B cell receptor peripheral tolerance. The induction of graft vs host reaction in mice that carry both a rearranged B cell Ag receptors specific for hen egg lysozyme and expressing chronically circulating hen egg lysozyme Ag resulted in induction of high and sustained levels of circulating anti-hen egg lysozyme autoantibodies and glomerulonephritis with proteinuria. This was associated with marked changes in expression of cell-surface proteins, such as CD23 and complement receptor 2. B cells from the graft vs host-induced mice could proliferate in vitro in response to self-Ag, and upon stimulation with anti-IgD demonstrated rapid phosphotyrosine phosphorylation of specific proteins, which could not be induced in the anergic double transgenic B cells. Conversely, loss of tolerance was not associated with a higher induction in the level of Syk kinase phosphorylation following stimulation with anti-IgD. Taken collectively, these data establish that 1) processes that induce a systemic lupus erythematosus-like syndrome in normal mice can abrogate peripheral tolerance in transgenic mice expressing self-tolerized B cells, and that 2) loss of tolerance in this model is associated with marked changes in surface expression of B cell coreceptors as well as with selective changes in IgD-induced signaling by discrete tyrosine-phosphoproteins, but not Syk kinase.
authors.affiliation: Division of Rheumatology, Department of Medicine, University of Pennsylvania, Philadelphia 19104, USA. Feuerstein@email.chop.edu
authors.forename: N
authors.initials: N
authors.lastname: Feuerstein
authors.forename: F
authors.initials: F
authors.lastname: Chen
authors.forename: M
authors.initials: M
authors.lastname: Madaio
authors.forename: M
authors.initials: M
authors.lastname: Maldonado
authors.forename: R A
authors.initials: RA
authors.lastname: Eisenberg
mesh_terms: D000818:Animals; D001323:Autoantibodies / Q000097:blood; D001324:Autoantigens / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology; D004195:Disease Models, Animal; D004792:Enzyme Precursors / Q000378:metabolism; D006087:Graft vs Host Reaction / Q000235:genetics / Q000276:immunology; D007108:Immune Tolerance / Q000235:genetics*; D007072:Immunoglobulin D / Q000235:genetics; D007075:Immunoglobulin M / Q000235:genetics; D047908:Intracellular Signaling Peptides and Proteins; D008180:Lupus Erythematosus, Systemic / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism; D008181:Lupus Nephritis / Q000276:immunology; D008213:Lymphocyte Activation / Q000235:genetics; D008565:Membrane Proteins / Q000096:biosynthesis; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009113:Muramidase / Q000235:genetics / Q000276:immunology; D010750:Phosphoproteins / Q000096:biosynthesis*; D019000:Phosphotyrosine / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D011947:Receptors, Antigen, B-Cell / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D017634:Self Tolerance / Q000235:genetics; D000072377:Syk Kinase
chemical_list: D001323:Autoantibodies; D001324:Autoantigens; D004792:Enzyme Precursors; D007072:Immunoglobulin D; D007075:Immunoglobulin M; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D010750:Phosphoproteins; D011947:Receptors, Antigen, B-Cell; D019000:Phosphotyrosine; D011505:Protein-Tyrosine Kinases; D000072377:Syk Kinase; C000606897:Syk protein, mouse; D009113:Muramidase