title: Macrophages from patients with atopic dermatitis show a reduced CXCL10 expression in response to staphylococcal α-toxin.
abstract: BACKGROUND
  Patients with atopic dermatitis (AD) are frequently colonized with Staphylococcus aureus (S. aureus), one-third of them producing α-toxin, which is correlated with the severity of eczema in AD. Staphylococcus aureus colonizes in patients with psoriasis as well. Distinct expression of chemokine (C-C motif) ligand (CCL) and chemokine (C-X-C motif) ligand (CXCL) chemokines has been documented in both diseases. In this study, we investigated the effects of sublytic α-toxin concentrations on human macrophages that accumulate in the skin of patients with AD and psoriasis.
  
  
  METHODS
  IFN-γ-induced protein of 10-kDa (IP-10)/CXCL10 and macrophage-derived chemokine (MDC)/CCL22 production were evaluated at the mRNA or at the protein level using qRT-PCR or ELISA, respectively. Cell surface markers' expression and chemotaxis were determined by flow cytometry and Boyden chamber technique, respectively.
  
  
  RESULTS
  Sublytic concentrations of α-toxin strongly induced CXCL10 in macrophages at both the mRNA and the protein levels and significantly up-regulated MHC class II expression. Supernatants of α-toxin-stimulated macrophages induced the migration of human CD4+ lymphocytes via the CXCL10 receptor (CXCR3). Macrophages from patients with AD produced lower levels of CXCL10 compared to cells from patients with psoriasis as well as healthy controls in response to α-toxin. α-Toxin did not lead to a large variation in CCL22 production in macrophages from all three groups.
  
  
  CONCLUSIONS
  Staphylococcal α-toxin contributes to Th1 polarization by induction of CXCL10 in macrophages. Macrophages from patients with AD and psoriasis responded to α-toxin in the induction of Th1-related chemokine CXCL10 diversely, which could favour the recruitment of distinct leucocyte subsets into the skin.
authors: Division of Immunodermatology and Allergy Research, Department of Dermatology and Allergy, Hannover Medical School, Carl-Neuburg-Strasse 1, Hannover,Germany. kasraie.sadaf@mh-hannover.de
authors: S
authors: S
authors: Kasraie
authors: M
authors: M
authors: Niebuhr
authors: V
authors: V
authors: Kopfnagel
authors: O
authors: O
authors: Dittrich-Breiholz
authors: M
authors: M
authors: Kracht
authors: T
authors: T
authors: Werfel
mesh_terms: D001427:Bacterial Toxins / Q000276:immunology*; D015153:Blotting, Western; D002454:Cell Differentiation / Q000276:immunology; D002465:Cell Movement / Q000276:immunology; D002469:Cell Separation; D002478:Cells, Cultured; D054357:Chemokine CXCL10 / Q000096:biosynthesis* / Q000276:immunology; D003876:Dermatitis, Atopic / Q000150:complications / Q000276:immunology* / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D008264:Macrophages / Q000276:immunology* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013207:Staphylococcal Skin Infections / Q000150:complications / Q000276:immunology; D013211:Staphylococcus aureus / Q000276:immunology*; D018417:Th1 Cells / Q000166:cytology / Q000276:immunology
chemical_list: D001427:Bacterial Toxins; C114753:CXCL10 protein, human; D054357:Chemokine CXCL10