Genetic Interdependence of Lyn and Negative Regulators of B Cell Receptor Signaling in Autoimmune Disease Development
Details
Publication Year 2012-08-15,Volume 189,Issue #4,Page 1726-1736
Journal Title
JOURNAL OF IMMUNOLOGY
Publication Type
Journal Article
Abstract
Ab-mediated autoimmune disease is multifaceted and may involve many susceptibility loci. The majority of autoimmune patients are thought to have polymorphisms in a number of genes that interact in different combinations to contribute to disease pathogenesis. Studies in mice and humans have implicated the Lyn protein tyrosine kinase as a regulator of Ab-mediated autoimmune disease. To examine whether haploinsufficiency of Lyn gives rise to cellular and clinical manifestations of autoimmune disease, we evaluated the phenotype of Lyn(+/-) mice. We find that their B cell compartment is significantly perturbed, with reduced numbers of marginal zone and transitional stage 2 B cells, expansion of plasma cells, downregulation of surface IgM, and upregulation of costimulatory molecules. Biochemical studies show that Lyn(+/-) B cells have defects in negative regulation of signaling, whereas Lyn(+/-) mice develop IgG autoantibodies and glomerulonephritis with age. Because Lyn has a pivotal role in the activation of inhibitory phosphatases, we generated mice harboring double heterozygous loss-of-function mutations in Lyn and SHP-1 or Lyn and SHIP-1. Partial inactivation of SHP-1 or SHIP-1 amplifies the consequence of Lyn haploinsufficiency, leading to an accelerated development of autoantibodies and disease. Our data also reveal that the BALB/c background is protective against autoimmune-mediated glomerulonephritis, even in the face of high titer autoantibodies, whereas the C57BL/6 background is susceptible. This study demonstrates that Lyn is a haploinsufficient gene in autoimmune disease and importantly shows that quantitative genetic variation in Lyn-regulated pathways can mirror the complete loss of a single critical inhibitory molecule. The Journal of Immunology, 2012, 189: 1726-1736.
Publisher
AMER ASSOC IMMUNOLOGISTS
Keywords
SYSTEMIC-LUPUS-ERYTHEMATOSUS; DEFICIENT MICE; TYROSINE KINASE; AUTOANTIBODY PRODUCTION; SERUM IMMUNOGLOBULINS; VIABLE MOTHEATEN; PIR-B; SHIP; CD22; ACTIVATION
Research Division(s)
Immunology
Terms of Use/Rights Notice
Copyright ©2013 by The American Association of Immunologists, Inc. All rights reserved


Creation Date: 2012-08-15 12:00:00
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