Autoimmune Regulator Is Expressed in the Cells Regulating Immune Tolerance in Thymus Medulla

Heino, Maarit; Peterson, Pärt; Kudoh, Jun; Nagamine, Kentaro; Lagerstedt, Anssi; Ovod, Vladimir; Ranki, Annamari; Rantala, Immo; Nieminen, Markku S.; Tuukkanen, Juha; Scott, Hamish S.; Antonarakis, Stylianos E.; Shimizu, Nobuyoshi; Krohn, Kai

doi:10.1006/bbrc.1999.0308

Cited by 268 publications

(236 citation statements)

References 34 publications

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“…This marked difference in the clonal distribution of Treg cells in patients and controls suggests a wider aberration, because an Ag-specific failure would be expected to manifest as narrow holes in an otherwise normal repertoire. Also, AIRE is expressed in peripheral tissues (4,5), albeit at lower levels than in the thymus, and it may be associated with the differentiation of dendritic cells or their interaction with T cells (37)(38)(39). Disruption of dendritic cell function could well contribute to the kind of defect observed in our analysis of TCR repertoire.…”

Section: Discussionmentioning

confidence: 94%

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A Defect of Regulatory T Cells in Patients with Autoimmune Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy

Kekäläinen¹,

Tuovinen²,

Joensuu³

et al. 2007

The Journal of Immunology

189

142

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Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED), a monogenic recessive disease characterized by autoimmunity against multiple tissues, offers a unique possibility to study the breakdown of self-tolerance in humans. It is caused by mutations in the autoimmune regulator gene (AIRE), which encodes a transcriptional regulator. Work using Aire−/− mice suggests that Aire induces ectopic expression of peripheral Ags and promotes their presentation in the thymus. We have explored reasons for the difference between the comparatively mild phenotype of Aire-deficient mice and human APECED patients. We provide evidence that, unlike in the Aire−/− mice, in the patients a key mediator of active tolerance, the CD4+CD25+ regulatory T (Treg) cell subset is impaired. This was shown by significantly decreased expression of FOXP3 mRNA and protein, decreased function, and alterations in TCR repertoire. Also, in the normal human thymus a concentric accumulation of AIRE+ cells was seen around thymic Hassall’s corpuscles, suggesting that in the patients these cells may be involved in the observed Treg cell failure. In Aire−/− mice the expression of FoxP3 was normal and even increased in target tissues in parallel with the lymphocyte infiltration process. Our results suggest that a Treg cell defect is involved in the pathogenesis of APECED and emphasize the importance of active tolerance mechanisms in preventing human autoimmunity.

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Section: Discussionmentioning

confidence: 94%

“…AIRE is strongly expressed in thymic medullary epithelial cells (MECs) and at lower levels in many peripheral tissues, including spleen and lymph nodes (4,5).…”

mentioning

confidence: 99%

A Defect of Regulatory T Cells in Patients with Autoimmune Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy

Kekäläinen¹,

Tuovinen²,

Joensuu³

et al. 2007

The Journal of Immunology

189

142

View full text Add to dashboard Cite

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“…Moreover, the PHD1 domain of AIRE has been suggested to have an E3 ubiquitin ligase activity in cell-free assays [19], findings in variance with a recent report [20]. Aire is highly expressed in a subset of the medullary thymic epithelial cells (mTEC) as well as in DC in the spleen and lymph nodes [21][22][23][24], indicating a potential role in immunological tolerance.To characterize the function of Aire, we previously engineered an Aire-deficient mouse targeting the most common APS I mutation [4]. Aire-deficient mice develop multiple organ-specific autoantibodies and lymphocytic infiltrates, thus mimicking some of the features of human APS I [4].…”

mentioning

confidence: 76%

Increased antigen presenting cell‐mediated T cell activation in mice and patients without the autoimmune regulator

et al. 2006

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Patients with autoimmune polyendocrine syndrome type I (APS I)suffer from endocrine and non-endocrine disorders due to mutations in the autoimmune regulator gene (AIRE). Mouse Aire is expressed both in thymic medullary epithelial cells and in peripheral antigen-presenting cells, suggesting a role in both central and peripheral tolerance. We here report that Aire -/-dendritic cells (DC) activate naive T cells more efficiently than do Aire +/+ DC. Expression array analyses of Aire -/-DC revealed differential regulation of 68 transcripts, among which, the vascular cell adhesion molecule-1 (VCAM-1) transcript was up-regulated in Aire -/-DC. Concurrently, the expression of the VCAM-1 protein was up-regulated on both Aire -/-DC and monocytes from APS I patients. Blocking the interaction of VCAM-1 prevented enhanced Aire -/-DC stimulation of T cell hybridomas. We determined an increased number of DC in spleen and lymph nodes and of monocytes in the blood from Aire -/-mice, and an increased number of blood monocytes in APS I patients. Our findings imply a role for Aire in peripheral DC regulation of T cell activation, and suggest that Aire participates in peripheral tolerance.Supporting information for this article is available at http://www.wiley-vch.de/contents/jc_2040/2006/35240_s.pdf IntroductionInactivation of the autoimmune regulator gene (AIRE) [1][2][3] causes autoimmunity in patients with autoimmune polyendocrine syndrome type I (APS I, APECED, OMIM 240300) and in a gene targeted mouse model [4,5]. APS I is a rare monogenic autosomal recessive disease without HLA association [6,7], which is prevalent in isolated populations [8][9][10]. APS I patients develop a progressive loss of tolerance against self antigens and suffer from multiorgan failures due to the immunological destruction of adrenals, parathyroid glands and b cells of the islets of Langerhans [11]. Many of the APS I organ-specific autoantigens have been identified and characterized [12,13]. In addition, as a sign of immune dysfunction, these patients have difficulties clearing Candida albicans infections in mucosal membranes [14]. Functional studies of AIRE suggest a role as a transcription factor and in vitro transactivating studies support this notion [15][16][17][18]. Moreover, the PHD1 domain of AIRE has been suggested to have an E3 ubiquitin ligase activity in cell-free assays [19], findings in variance with a recent report [20]. Aire is highly expressed in a subset of the medullary thymic epithelial cells (mTEC) as well as in DC in the spleen and lymph nodes [21][22][23][24], indicating a potential role in immunological tolerance.To characterize the function of Aire, we previously engineered an Aire-deficient mouse targeting the most common APS I mutation [4]. Aire-deficient mice develop multiple organ-specific autoantibodies and lymphocytic infiltrates, thus mimicking some of the features of human APS I [4]. Subsequently, the role of Aire in negative selection was demonstrated [5]. These findings were further supported using TCR transgenic mic...

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“…Human AIRE is expressed in the medullar epithelial cells and monocyte-dendritic cells of the thymus with lower expression in the spleen, foetal liver, and lymph node paracortex and medulla. The AIRE protein was not found in target organs of autoimmune destruction [157]. In adult mice, however, AIRE expression was found in bone marrow, kidney, testis, adrenal gland, liver and ovary [158,159].…”

Section: ªMonogenicº Diabetes Syndromesmentioning

confidence: 91%

Genetic control of autoimmunity in Type I diabetes and associated disorders

2002

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Type I (insulin-dependent) diabetes mellitus is a heterogeneous disease with major subdivisions termed Type 1A (immune-mediated) and Type 1B. Immunemediated diabetes is also heterogeneous with ªmono-genicº, oligogenic, and polygenic forms present in humans and in animal models. Single-gene mutations of two transcription factors have been recently identified in rare syndromes of autoimmunity with type 1A diabetes: autoimmune polyendocrine syndrome type 1 (APS-1) and X-linked polyendocrinopathy, immune dysfunction and diarrhoea (XPID). For more common forms of diabetes, susceptibility loci within the major histocompatibility complex and at the insulin locus have been identified. Both DQ* and DR* alleles provide susceptibility and certain alleles dominant protection. In the Diabetes Autoimmunity Study of the Young approximately 50 % of the siblings studied with the highest-risk HLA genotype develop anti-islet autoantibodies by age 3. Insulin could be a crucial autoantigen related to genetic susceptibility. The crystal structure of the high-risk allele, HLA-DQ8, complexed with an insulin peptide has just been reported. Insulin production by macrophage-dendritic cells within the thymus and lymphoid organs could underlie insulin gene polymorphisms influencing the risk of diabetes. Genome-wide scans for linkage in animal models and in humans have not conclusively identified other susceptibility genes though many loci have been implicated. We favour the hypothesis that HLA is a major determinant of susceptibility in animal models and in most families, and that the search for diabetogenes should concentrate on unique families to decrease heterogeneity and favour the eventual discovery of genes influencing risk. [Diabetologia (2002) 45:605±622]

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Autoimmune Regulator Is Expressed in the Cells Regulating Immune Tolerance in Thymus Medulla

Cited by 268 publications

References 34 publications

A Defect of Regulatory T Cells in Patients with Autoimmune Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy

A Defect of Regulatory T Cells in Patients with Autoimmune Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy

Increased antigen presenting cell‐mediated T cell activation in mice and patients without the autoimmune regulator

Genetic control of autoimmunity in Type I diabetes and associated disorders

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