title: Generation and functional analysis of human TNF-α/iNOS-producing dendritic cells (Tip-DC).
abstract: BACKGROUND
  A unique type of CD11c(pos) dendritic cells (DC) is abundant in inflamed tissue, for example, in chronic inflammatory skin diseases. Due to their remarkable production of tumor necrosis factor (TNF)-α and inducible NO synthase (iNOS), these cells have been referred to as TNF and iNOS-producing DC (Tip-DC). While Tip-DC have been mainly characterized in murine models of infection, functional data about their human counterpart are lacking.
  
  
  OBJECTIVE
  We sought to generate human Tip-DC in vitro und thus provide a new model for the investigation of their phenotype and function.
  
  
  METHODS
  We generated human Tip-DC from monocytic precursor cells of healthy individuals, atopic and psoriatic patients using human serum. Resting and stimulated cells were analyzed by flow cytometry, real-time PCR, and by ELISA. INOS activity was measured by fluorometric detection of NO.
  
  
  RESULTS
  Tip-DC closely resembled their in vivo counterparts by expressing CD11c, CD86, and CD40 while lacking CD1a, CD1c, or CD207/Langerin. Bacterial stimulation of Tip-DC from healthy donors, atopic dermatitis, or psoriasis patients resulted in a similar increase in iNOS activity and TNF-α production. In kinetic experiments, TNF-α, a putative activator of Tip-DC, could not induce NOS2. Upon bacterial stimulation, TNFA, IL6, IL12B, and IL23A mRNA appeared in a first wave, while IL12A and NOS2 mRNA were up-regulated later on but not blocked by anti-TNF-α agents, implying a biphasic pro-inflammatory response.
  
  
  CONCLUSIONS
  We developed a new model for the study of human Tip-DC and provide the first evidence of their pro-inflammatory capacity.
authors.affiliation: Department of Dermatology and Allergy, Rheinische Friedrich Wilhelms University of Bonn, Bonn, Germany. dagmar.wilsmann-theis@ukb.uni-bonn.de
authors.forename: D
authors.initials: D
authors.lastname: Wilsmann-Theis
authors.forename: S
authors.initials: S
authors.lastname: Koch
authors.forename: C
authors.initials: C
authors.lastname: Mindnich
authors.forename: S
authors.initials: S
authors.lastname: Bonness
authors.forename: S
authors.initials: S
authors.lastname: Schnautz
authors.forename: D
authors.initials: D
authors.lastname: von Bubnoff
authors.forename: T
authors.initials: T
authors.lastname: Bieber
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D016207:Cytokines / Q000276:immunology / Q000378:metabolism*; D003713:Dendritic Cells / Q000276:immunology* / Q000378:metabolism; D003876:Dermatitis, Atopic / Q000276:immunology / Q000503:physiopathology; D005434:Flow Cytometry; D006801:Humans; D051379:Mice; D009000:Monocytes / Q000276:immunology / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000096:biosynthesis* / Q000276:immunology; D011565:Psoriasis / Q000276:immunology / Q000503:physiopathology; D060888:Real-Time Polymerase Chain Reaction; D012016:Reference Values; D018709:Statistics, Nonparametric; D051193:Toll-Like Receptors / Q000276:immunology / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000276:immunology
chemical_list: D016207:Cytokines; D051193:Toll-Like Receptors; D014409:Tumor Necrosis Factor-alpha; C496319:NOS2 protein, human; D052247:Nitric Oxide Synthase Type II
keywords: TNF-α and iNOS-producing DC; atopic dermatitis; dendritic cells; inducible NO synthase; psoriasis