title: Mapping of B cell epitopes on desmoglein 3 in pemphigus vulgaris patients by the use of overlapping peptides.
abstract: BACKGROUND
  Pemphigus vulgaris (PV) is a severe autoimmune blistering disease associated with autoantibodies to desmoglein 3 (Dsg 3), a transmembrane glycoprotein of the cadherin family. Previous studies mainly focused on the mapping of conformational epitopes of Dsg 3 using recombinant fragments of Dsg 3 and competition ELISA.
  
  
  OBJECTIVE
  Here, we performed a mapping of linear B cell epitopes on Dsg 3 in PV patients by the use of overlapping synthetic peptides.
  
  
  METHODS
  A set of 254 overlapping synthetic peptides of 14 amino acids length covering the entire Dsg 3 extracellular domain was generated. Sera of patients with active PV (n=10) and healthy volunteers (n=10) were tested for IgG reactivity with the 254 peptides by ELISA. Testing each peptide separately, 7 major antigenic sites were identified. In order to validate these reactivities, 7 corresponding peptides of 13-33 amino acids in length were generated and employed by ELISA. Additional sera of active PV patients (n=17) and healthy volunteers (n=20) were tested and the most reactive peptide was used to specifically purify anti-Dsg 3 antibodies from PV sera (n=3).
  
  
  RESULTS
  The major autoantibody reactivity in PV sera was mapped to amino acids 333-356 within the EC3 domain. Purifying patients IgG using the identified peptide, however, failed to induce acantholysis in keratinocyte dissociation assay.
  
  
  CONCLUSIONS
  We conclude that linear epitopes do not play a major pathogenic role in human PV.
authors.affiliation: Department of Dermatology, University of Lübeck, Lübeck, Germany.
authors.forename: Jenny
authors.initials: J
authors.lastname: Dworschak
authors.forename: Andreas
authors.initials: A
authors.lastname: Recke
authors.forename: Miriam
authors.initials: M
authors.lastname: Freitag
authors.forename: Ralf J
authors.initials: RJ
authors.lastname: Ludwig
authors.forename: Jana
authors.initials: J
authors.lastname: Langenhan
authors.forename: Oliver J
authors.initials: OJ
authors.lastname: Kreuzer
authors.forename: Detlef
authors.initials: D
authors.lastname: Zillikens
authors.forename: Enno
authors.initials: E
authors.lastname: Schmidt
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001323:Autoantibodies / Q000008:administration & dosage / Q000097:blood*; D016022:Case-Control Studies; D002460:Cell Line; D051184:Desmoglein 3 / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D018604:Epitope Mapping / Q000379:methods*; D018985:Epitopes, B-Lymphocyte / Q000276:immunology*; D005858:Germany; D006801:Humans; D007116:Immunization, Passive; D007279:Injections, Subcutaneous; D015603:Keratinocytes / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D010392:Pemphigus / Q000097:blood / Q000276:immunology* / Q000473:pathology; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000276:immunology*; D017434:Protein Structure, Tertiary
chemical_list: D001323:Autoantibodies; C071894:DSG3 protein, human; D051184:Desmoglein 3; D018985:Epitopes, B-Lymphocyte; D010446:Peptide Fragments