Aire is not essential for regulating neuroinflammatory disease in mice transgenic for human autoimmune-diseases associated MHC class II genes HLA-DR2b and HLA-DR4

Cell Immunol. 2018 Sep:331:38-48. doi: 10.1016/j.cellimm.2018.05.003. Epub 2018 May 14.

Abstract

The human autoimmune disease-associated HLA alleles HLA-DR2b (DRB1*1501) and HLA-DR4 (DRB1*0401) are strongly linked to increased susceptibility for multiple sclerosis (MS) and rheumatoid arthritis (RA), respectively. The underlying mechanisms are not fully understood, but these MHC alleles may shape the repertoire of pathogenic T cells via central tolerance. The transcription factor autoimmune regulator (AIRE) promotes central T cell tolerance via ectopic expression of tissue-specific antigens (TSAs). Aire deficiency in humans causes autoimmune polyendocrinopathy syndrome type 1 (APS1), and Aire knockout mice (Aire-/-) develop spontaneous autoimmune pathology characterized by multi-organ lymphocytic infiltrates. Here, we asked whether impaired TSAs gene expression in the absence of Aire promoted spontaneous MS- or RA-like autoimmune pathology in the context of human HLA alleles in HLA-DR2b or HLA-DR4 transgenic (tg) mice. The results show that reduced TSAs gene expression in the thymus of Aire-deficient HLA-DR2b or HLA-DR4 tg mice corresponded to mild spontaneous inflammatory infiltrates in salivary glands, liver, and pancreas. Moreover, Aire-deficiency modestly enhanced experimental autoimmune encephalomyelitis (EAE) in HLA-DR tg mice, but the animals did not show signs of spontaneous neuroinflammation or arthritis. No significant changes were observed in CD4+ T cell numbers, T cell receptor (TCR) distribution, regulatory T cells (Treg), or antigen-induced cytokine production. Abrogating Treg function by treatment with anti-CTLA-4 or anti-CD25 mAb in Aire-deficient HLA-DR tg mice did not trigger EAE or other autoimmune pathology. Our results suggest a redundant role for Aire in maintaining immune tolerance in the context of autoimmune disease-associated human HLA alleles.

Keywords: Aire; EAE; T cells.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • AIRE Protein
  • Animals
  • Antigens / immunology
  • Antigens / metabolism
  • Arthritis, Rheumatoid / genetics
  • Arthritis, Rheumatoid / immunology
  • Arthritis, Rheumatoid / metabolism
  • Autoimmune Diseases / genetics
  • Autoimmune Diseases / immunology*
  • Autoimmune Diseases / metabolism
  • Encephalomyelitis, Autoimmune, Experimental / genetics
  • Encephalomyelitis, Autoimmune, Experimental / immunology*
  • Encephalomyelitis, Autoimmune, Experimental / metabolism
  • HLA-DR2 Antigen / genetics
  • HLA-DR2 Antigen / immunology*
  • HLA-DR2 Antigen / metabolism
  • HLA-DR4 Antigen / genetics
  • HLA-DR4 Antigen / immunology*
  • HLA-DR4 Antigen / metabolism
  • Humans
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Mice, Transgenic
  • Multiple Sclerosis / genetics
  • Multiple Sclerosis / immunology
  • Multiple Sclerosis / metabolism
  • Organ Specificity / immunology
  • T-Lymphocytes / immunology
  • T-Lymphocytes / metabolism
  • Transcription Factors / genetics
  • Transcription Factors / immunology*
  • Transcription Factors / metabolism

Substances

  • Antigens
  • HLA-DR2 Antigen
  • HLA-DR4 Antigen
  • Transcription Factors