title: DNFB activates MAPKs and upregulates CD40 in skin-derived dendritic cells.
abstract: BACKGROUND
  The intracellular mechanisms involved in the activation of DCs during sensitization in allergic contact dermatitis (ACD) are not known.
  
  
  OBJECTIVE
  Here, we investigated the effect of a strong sensitizer, 2,4-dinitrofluorobenzene (DNFB) on the activity of MAPKs in a dendritic cell (DC) line generated from fetal mouse skin (FSDC), and the results were correlated with the expression of a costimulatory molecule upregulated upon DC maturation, CD40.
  
  
  METHODS
  Phosphorylation of ERK1/2 (pERK1/2) and p38 MAPK (pp38 MAPK), and CD40 protein levels, were determined by Western blot. Cellular localization of pERK1/2 and pp38 MAPK were determined by immunocytochemistry using phospho-specific antibodies.
  
  
  RESULTS
  Although with different kinetics, DNFB activated ERK1/2 and p38 MAPK, and induced the translocation of the phosphorylated forms of the kinases to the nucleus. In addition, DNFB upregulated significantly CD40 protein levels in FSDC. However, 2,4-dichloronitrobenzene (DCNB), an inactive analogue of DNFB, did not affect significantly the phosphorylation of MAPKs and CD40 protein levels. SB203580 and SB202190, inhibitors of the p38 MAPK activity, inhibited DNFB-induced CD40 upregulation, although this effect did not reach statistical significance. In contrast, PD 98059 and U0126, inhibitors of mitogen or extracellular signal-regulated kinase (MEK), had no effect on the CD40 upregulation induced by DNFB.
  
  
  CONCLUSIONS
  Taken together, these results indicate that the strong sensitizer DNFB activates ERK1/2 and p38 MAPK signaling pathways, and upregulates CD40 protein levels. However, MAPKs do not play a major role in the induction of CD40, one of the phenotypic markers of DC maturation.
authors.affiliation: Centro de Neurosciências e Biologia Celular, Universidade de Coimbra, Portugal.
authors.forename: Teresa J
authors.initials: TJ
authors.lastname: Matos
authors.forename: Carlos B
authors.initials: CB
authors.lastname: Duarte
authors.forename: Margarida
authors.initials: M
authors.lastname: Gonçalo
authors.forename: M Celeste
authors.initials: MC
authors.lastname: Lopes
mesh_terms: D021581:Active Transport, Cell Nucleus; D000818:Animals; D015153:Blotting, Western; D019013:CD40 Antigens / Q000096:biosynthesis*; D002460:Cell Line; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000166:cytology*; D017449:Dermatitis, Allergic Contact / Q000276:immunology; D004139:Dinitrofluorobenzene / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D007150:Immunohistochemistry; D007700:Kinetics; D020935:MAP Kinase Signaling System; D051379:Mice; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D009578:Nitrobenzenes / Q000494:pharmacology; D010641:Phenotype; D010766:Phosphorylation; D011725:Pyridines / Q000494:pharmacology; D015398:Signal Transduction; D012867:Skin / Q000473:pathology; D013997:Time Factors; D015854:Up-Regulation; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D019013:CD40 Antigens; D007093:Imidazoles; D009578:Nitrobenzenes; D011725:Pyridines; C053747:2,4-dichloro-1-nitrobenzene; D004139:Dinitrofluorobenzene; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D048051:p38 Mitogen-Activated Protein Kinases; C093642:SB 203580; C090942:4-(4-fluorophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)imidazole