LatY136F knock-in mouse model for human IgG4-related disease

PLoS One. 2018 Jun 14;13(6):e0198417. doi: 10.1371/journal.pone.0198417. eCollection 2018.

Abstract

Background: The adaptor protein Linker for activation of T cell (LAT) is a key signaling hub used by the T cell antigen receptor. Mutant mice expressing loss-of-function mutations affecting LAT and including a mutation in which tyrosine 136 is replaced by a phenylalanine (LatY136F) develop lymphoproliferative disorder involving T helper type 2 effector cells capable of triggering a massive polyclonal B cell activation that leads to hypergammaglobulinemia G1 and E and to non-resolving inflammation and autoimmunity. The purpose of this study was to evaluate whether the phenotypes of LatY136F knock-in mice resemble the immunohistopathological features of immunoglobulin G4-related disease (IgG4-RD).

Methods: LatY136F knock-in mice were sacrificed at 4-20 weeks of age, and pancreas, kidney, salivary gland and lung were obtained. All organs were stained with hematoxylin-eosin and with Azan for estimation of collagen in fibrosis, and the severity scores of inflammation and fibrosis were evaluated. Immunostainings were performed to analyze the types of infiltrating cells. In addition, the effects of corticosteroid treatment on the development of tissue lesions and serum levels of IgG1 were assessed.

Results: Tissue lesions characterized by inflammatory mononuclear cell infiltration and fibrosis were detected in pancreas, kidney, and salivary gland starting from 6 weeks of age. Immunostainings showed pronounced infiltration of plasma cells, CD4-positive T cells, and macrophages. Infiltrating plasma cells predominantly expressed IgG1. The extent of inflammation in pancreas and salivary glands was markedly reduced by corticosteroid treatment.

Conclusions: LatY136F knock-in mice displayed increased production of Th2-type IgG1 (a homologue of human IgG4) and developed multiple organ tissue lesions reminiscent of those seen in patients with IgG4-RD. Moreover, the development of these tissue lesions was highly sensitive to corticosteroid treatment like in IgG4-RD. For these reasons we consider the LatY136F knock-in mouse strain to represent a promising model for human IgG4-RD.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / genetics*
  • Adrenal Cortex Hormones / administration & dosage
  • Adrenal Cortex Hormones / pharmacology
  • Animals
  • Disease Models, Animal*
  • Gene Knock-In Techniques
  • Humans
  • Immunoglobulin G4-Related Disease / drug therapy
  • Immunoglobulin G4-Related Disease / genetics*
  • Immunoglobulin G4-Related Disease / immunology
  • Immunoglobulin G4-Related Disease / pathology*
  • Kidney / drug effects
  • Kidney / immunology
  • Kidney / pathology
  • Leukocytes, Mononuclear / immunology*
  • Lung / drug effects
  • Lung / immunology
  • Lung / pathology
  • Membrane Proteins / genetics*
  • Mice
  • Mutation*
  • Pancreas / drug effects
  • Pancreas / immunology
  • Pancreas / pathology
  • Phenotype
  • Phenylalanine / genetics
  • Phosphoproteins / genetics*
  • Salivary Glands / drug effects
  • Salivary Glands / immunology
  • Salivary Glands / pathology
  • Tyrosine / genetics

Substances

  • Adaptor Proteins, Signal Transducing
  • Adrenal Cortex Hormones
  • Lat protein, mouse
  • Membrane Proteins
  • Phosphoproteins
  • Tyrosine
  • Phenylalanine

Grants and funding

This work was supported by the Research Program of Intractable Diseases of the Ministry of Health, Labor, and Welfare of Japan (http://www.mhlw.go.jp/english/) to MK; JSPS KAKENHI, 26461487 (https://www.jsps.go.jp/english/e-grants/) to MK; JSPS KAKENHI, 17K09999 (https://www.jsps.go.jp/english/e-grants/) to KY and A grant-in-aid from THE KATO MEMORIAL NAMBYO RESEARCH to KY. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.