title: Involvement of granzyme B and granulysin in the cytotoxic response in lichen planus.
abstract: BACKGROUND
  Lichen planus is an inflammatory dermatosis involving either skin and/or mucosal epithelial surfaces. A cell-mediated cytotoxicity response is the main suspected mechanism of this dermatosis. Granzyme B and granulysin are components of the cytoplasmic granules of cytotoxic T lymphocytes and natural killers. They are involved in cell-mediated apoptosis. This work studies the possible implication of granzyme B and granulysin in the cell-mediated cytotoxicity response in lichen planus.
  
  
  METHODS
  In situ expression of granzyme B and granulysin was studied by real-time reverse transcriptase polymerase chain reaction in 15 biopsies of lichen planus. The distribution and the phenotype of the inflammatory infiltrate and the expression of granzyme B were studied by immunohistochemistry in seven other biopsies of lichen planus.
  
  
  RESULTS
  Granzyme B and granulysin mRNA expression was one to two hundred times greater than in biopsies of normal skin. Immunohistochemical study revealed that the lymphohistiocytic infiltrate consisted mainly of CD4+ and CD8+ lymphocytes. Granzyme B+ cells were observed close to apoptotic keratinocytes.
  
  
  CONCLUSIONS
  Our results suggest a central role for cell-mediated cytotoxicity by the granule exocytosis pathway probably because of auto-cytotoxic T-cell clones in the pathogenesis of lichen planus.
authors.affiliation: Laboratoire d'Immunologie, de Génétique et de Pathologie Humaine, Faculté des Sciences, Tunis, Tunisie. myriambensaid@yahoo.fr
authors.forename: M
authors.initials: M
authors.lastname: Ammar
authors.forename: M
authors.initials: M
authors.lastname: Mokni
authors.forename: S
authors.initials: S
authors.lastname: Boubaker
authors.forename: Amel
authors.initials: A
authors.lastname: El Gaied
authors.forename: A
authors.initials: A
authors.lastname: Ben Osman
authors.forename: H
authors.initials: H
authors.lastname: Louzir
mesh_terms: D000293:Adolescent; D000328:Adult; D015703:Antigens, CD / Q000378:metabolism; D000945:Antigens, Differentiation, T-Lymphocyte / Q000235:genetics / Q000378:metabolism*; D017209:Apoptosis / Q000276:immunology; D002648:Child; D005260:Female; D053804:Granzymes / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D016130:Immunophenotyping; D008010:Lichen Planus / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012867:Skin / Q000473:pathology; D018709:Statistics, Nonparametric; D013602:T-Lymphocytes, Cytotoxic / Q000378:metabolism
chemical_list: D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; C075005:GNLY protein, human; D012333:RNA, Messenger; D053804:Granzymes