title: Thymic stromal lymphopoietin-activated invariant natural killer T cells trigger an innate allergic immune response in atopic dermatitis.
abstract: BACKGROUND
  Although invariant natural killer T (iNKT) cells have been shown to play a critical role in the pathogenesis of asthma, the role of iNKT cells in atopic dermatitis (AD) has not been well evaluated.
  
  
  OBJECTIVE
  We investigated whether iNKT cells in patients with AD increased and whether iNKT cells were activated by thymic stromal lymphopoietin (TSLP), which is highly expressed in keratinocytes of AD.
  
  
  METHODS
  We assessed the population of iNKT cells in PBMCs of patients with AD and healthy controls (HCs) using flow cytometry. Immunohistochemistry was used to evaluate iNKT cells and TSLP expression in AD and HC skin. We also evaluated whether iNKT cells expressed the TSLP receptor, the effects of TSLP on iNKT cells, and iNKT cell-dendritic cell interactions in a TSLP-rich environment.
  
  
  RESULTS
  There were more iNKT cells among PBMCs of patients with moderate to severe AD than mild AD (P < .05) and HC (P < .001). The number of iNKT cells was significantly larger in severe AD skin lesions than in mild (P < .001) or moderate AD skin lesions (P < .05). TSLP expression increased in lesional skin (P < .001) but not in the sera of patients with AD (P = .729) compared with HC. iNKT cells expressed TSLP receptor protein and mRNA. TSLP directly activated iNKT cells to secrete IL-4 and IL-13, and the concurrent addition of dendritic cells further activated IFN-gamma expression.
  
  
  CONCLUSIONS
  Increased iNKT cells activated by TSLP, especially in patients with severe AD, might play an essential role in the innate allergic immune response in AD.
authors.affiliation: Department of Dermatology and Cutaneous Biology Research Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Wen Hao
authors.initials: WH
authors.lastname: Wu
authors.forename: Chang Ook
authors.initials: CO
authors.lastname: Park
authors.forename: Sang Ho
authors.initials: SH
authors.lastname: Oh
authors.forename: Hee Jung
authors.initials: HJ
authors.lastname: Kim
authors.forename: Yeon Sook
authors.initials: YS
authors.lastname: Kwon
authors.forename: Byung Gi
authors.initials: BG
authors.lastname: Bae
authors.forename: Ji Yeon
authors.initials: JY
authors.lastname: Noh
authors.forename: Kwang Hoon
authors.initials: KH
authors.lastname: Lee
mesh_terms: D000328:Adult; D002450:Cell Communication / Q000276:immunology; D016207:Cytokines / Q000276:immunology* / Q000378:metabolism; D003713:Dendritic Cells / Q000276:immunology / Q000473:pathology; D003876:Dermatitis, Atopic / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D005260:Female; D005434:Flow Cytometry; D005786:Gene Expression Regulation / Q000276:immunology*; D006801:Humans; D007113:Immunity, Innate; D007150:Immunohistochemistry; D008213:Lymphocyte Activation / Q000276:immunology*; D008297:Male; D055611:Natural Killer T-Cells / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D018121:Receptors, Cytokine / Q000276:immunology / Q000378:metabolism; D012867:Skin / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D000094632:Thymic Stromal Lymphopoietin
chemical_list: C498762:CRLF2 protein, human; D016207:Cytokines; D018121:Receptors, Cytokine; D000094632:Thymic Stromal Lymphopoietin