title: The 3G5 antigen is expressed in dermal mast cells but not pericytes.
abstract: BACKGROUND
  It has been shown that the 3G5 antigen recognized by monoclonal antibody 3G5 (mAb 3G5) is a useful marker of pericytes in normal human skin. However, most 3G5 antigen-expressing cells in capillary vessels were stained negatively for alpha-smooth muscle actin (alpha-SMA), a prominent pericyte marker. This study was designed to determine whether the expression of the 3G5 antigen is restricted to specific stages of pericyte development, or if it is expressed in other cells rather than pericytes in capillary vessels.
  
  
  METHODS
  3G5 antigen-expressing cells were detected in normal human skin, granulating tissues from decubitus ulcers and inflammatory psoriatic skin with extensive angiogenesis using double immunofluorescent staining with mAb 3G5 and monoclonal antibodies (mAbs) to various pericyte markers, tryptase and chymase. Furthermore, using immunoelectron microscopy, 3G5 antigen-expressing cells were observed in the granulating tissues.
  
  
  RESULTS
  The immunoelectron microscopic findings and double immunofluorescent staining (using mAb 3G5 and either anti-tryptase or anti-chymase mAbs) showed that 3G5 antigen-expressing cells were mast cells in normal skin, granulating tissues and psoriatic skin.
  
  
  CONCLUSIONS
  The results indicated that 3G5 antigen is a marker of mast cells, but not of pericytes in normal and diseased skin.
authors.affiliation: Department of Dermatology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima City, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Gushi
authors.forename: Masashi
authors.initials: M
authors.lastname: Tanaka
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Tsuyama
authors.forename: Taku
authors.initials: T
authors.lastname: Nagai
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Kanzaki
authors.forename: Takuro
authors.initials: T
authors.lastname: Kanekura
authors.forename: Takami
authors.initials: T
authors.lastname: Matsuyama
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology*; D015415:Biomarkers / Q000378:metabolism; D053818:Chymases / Q000276:immunology; D019084:Fluorescent Antibody Technique, Indirect; D005732:Gangliosides / Q000276:immunology / Q000378:metabolism*; D006097:Granulation Tissue / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D008407:Mast Cells / Q000378:metabolism* / Q000648:ultrastructure; D016253:Microscopy, Immunoelectron; D020286:Pericytes / Q000378:metabolism* / Q000648:ultrastructure; D003668:Pressure Ulcer / Q000378:metabolism / Q000473:pathology; D011565:Psoriasis / Q000378:metabolism / Q000473:pathology; D012867:Skin / Q000378:metabolism* / Q000473:pathology; D053802:Tryptases / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D015415:Biomarkers; D005732:Gangliosides; D053818:Chymases; D053802:Tryptases