title: Autoimmune regulator (AIRE) contributes to Dectin-1-induced TNF-α production and complexes with caspase recruitment domain-containing protein 9 (CARD9), spleen tyrosine kinase (Syk), and Dectin-1.
abstract: BACKGROUND
  Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) syndrome is a complex immunologic disease caused by mutation of the autoimmune regulator (AIRE) gene. Autoimmunity in patients with APECED syndrome has been shown to result from deficiency of AIRE function in transcriptional regulation of thymic peripheral tissue antigens, which leads to defective T-cell negative selection. Candidal susceptibility in patients with APECED syndrome is thought to result from aberrant adaptive immunity.
  
  
  OBJECTIVE
  To determine whether AIRE could function in anticandidal innate immune signaling, we investigated an extrathymic role for AIRE in the immune recognition of β-glucan through the Dectin-1 pathway, which is required for defense against Candida species.
  
  
  METHODS
  Innate immune signaling through the Dectin-1 pathway was assessed in both PBMCs from patients with APECED syndrome and a monocytic cell line. Subcellular localization of AIRE was assessed by using confocal microscopy.
  
  
  RESULTS
  PBMCs from patients with APECED syndrome had reduced TNF-α responses after Dectin-1 ligation but in part used a Raf-1-mediated pathway to preserve function. In the THP-1 human monocytic cell line, reducing AIRE expression resulted in significantly decreased TNF-α release after Dectin-1 ligation. AIRE formed a transient complex with the known Dectin-1 pathway components phosphorylated spleen tyrosine kinase and caspase recruitment domain-containing protein 9 after receptor ligation and localized with Dectin-1 at the cell membrane.
  
  
  CONCLUSIONS
  AIRE can participate in the Dectin-1 signaling pathway, indicating a novel extrathymic role for AIRE and a defect that likely contributes to fungal susceptibility in patients with APECED syndrome.
authors.affiliation: Center for Investigation in Pediatrics, University of Campinas Medical School, São Paulo, Brazil.
authors.forename: Luis A
authors.initials: LA
authors.lastname: Pedroza
authors.forename: Vipul
authors.initials: V
authors.lastname: Kumar
authors.forename: Keri B
authors.initials: KB
authors.lastname: Sanborn
authors.forename: Emily M
authors.initials: EM
authors.lastname: Mace
authors.forename: Harri
authors.initials: H
authors.lastname: Niinikoski
authors.forename: Kari
authors.initials: K
authors.lastname: Nadeau
authors.forename: Dewton de Moraes
authors.initials: Dde M
authors.lastname: Vasconcelos
authors.forename: Elena
authors.initials: E
authors.lastname: Perez
authors.forename: Soma
authors.initials: S
authors.lastname: Jyonouchi
authors.forename: Harumi
authors.initials: H
authors.lastname: Jyonouchi
authors.forename: Pinaki P
authors.initials: PP
authors.lastname: Banerjee
authors.forename: Olli
authors.initials: O
authors.lastname: Ruuskanen
authors.forename: Antonio
authors.initials: A
authors.lastname: Condino-Neto
authors.forename: Jordan S
authors.initials: JS
authors.lastname: Orange
mesh_terms: D053468:CARD Signaling Adaptor Proteins / Q000276:immunology*; D002460:Cell Line; D006801:Humans; D007113:Immunity, Innate; D047908:Intracellular Signaling Peptides and Proteins / Q000276:immunology*; D037181:Lectins, C-Type / Q000276:immunology*; D007963:Leukocytes, Mononuclear / Q000276:immunology; D018613:Microscopy, Confocal; D016884:Polyendocrinopathies, Autoimmune / Q000276:immunology*; D011505:Protein-Tyrosine Kinases / Q000276:immunology*; D000072377:Syk Kinase; D014157:Transcription Factors / Q000235:genetics / Q000276:immunology*; D014161:Transduction, Genetic; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology*; D047071:beta-Glucans / Q000494:pharmacology; D000096927:AIRE Protein; D000099181:Dectin-1
chemical_list: D053468:CARD Signaling Adaptor Proteins; D047908:Intracellular Signaling Peptides and Proteins; D037181:Lectins, C-Type; D011505:Protein-Tyrosine Kinases; D000072377:Syk Kinase; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha; D047071:beta-Glucans; D000096927:AIRE Protein; D000099181:Dectin-1; C505855:CARD9 protein, human; C038459:curdlan; C000606896:SYK protein, human