title: Expression patterns of sialylated epitope recognized by KL-6 monoclonal antibody in ocular surface epithelium of normals and dry eye patients.
abstract: OBJECTIVE
  To determine the association of the KL-6 epitope (sugar moiety) with MUC1 and its distribution on the ocular surface of human non-dry and dry eyes.
  
  
  METHODS
  The human ocular surface was examined immunohistochemically and immunoelectron microscopically using monoclonal antibody (mAb) KL-6, which recognize a carbohydrate epitope of MUC1. The expression patterns of KL-6 epitope in corneal and conjunctival cells were examined by impression cytology from 24 non-dry eye volunteers and 43 dry-eye patients.
  
  
  RESULTS
  In the cornea, bulbar conjunctiva, and limbus epithelium, mAb KL-6 reacted to the apical cell membrane of superficial cells and the intercellular space of superficial and wing cells. No immune reactivity of mAb KL-6 was observed in the basal plasma membrane of basal epithelial cells. Results of impression cytology indicated that the corneal epithelium of 13 of 24 non-dry eyes was weakly stained by mAb KL-6, whereas 42 of 43 dry eyes showed a mosaic pattern. In non-dry eyes, 19 of 24 bulbar conjunctival epithelia expressed the KL-6 epitope in a honeycomb pattern. In mild (17/19) and moderate (17/17) dry eye conjunctiva, the KL-6 epitope showed a mosaic pattern. However, the expression of KL-6 epitope decreased in severe dry eyes, showing a mosaic pattern in three of seven patients and labeling a few cells weakly in four of seven patients.
  
  
  CONCLUSIONS
  These findings suggest that there is an upregulation of the sialylated KL-6 epitope of MUC1 by apical corneal and conjunctival cells in mild and moderate dry eyes. This upregulation may in part alleviate the consequences caused by goblet cell mucin dysfunction in dry eyes. It is noteworthy that the KL-6 epitope is downregulated in the conjunctiva of severe dry eyes, a phenomenon that may be explained in part by the malfunction of conjunctival epithelial cells.
authors.affiliation: Department of Ophthalmology, Ehime University Medical School, Ehime, Japan. hayashy@email.uc.edu
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Hayashi
authors.forename: Winston W-Y
authors.initials: WW
authors.lastname: Kao
authors.forename: Nobuoki
authors.initials: N
authors.lastname: Kohno
authors.forename: Miyuki
authors.initials: M
authors.lastname: Nishihara-Hayashi
authors.forename: Atsushi
authors.initials: A
authors.lastname: Shiraishi
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Uno
authors.forename: Masahiko
authors.initials: M
authors.lastname: Yamaguchi
authors.forename: Shigeki
authors.initials: S
authors.lastname: Okamoto
authors.forename: Mitsuyo
authors.initials: M
authors.lastname: Maeda
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Ikeda
authors.forename: Hironobu
authors.initials: H
authors.lastname: Hamada
authors.forename: Keiichi
authors.initials: K
authors.lastname: Kondo
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Ohashi
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology*; D000941:Antigens / Q000276:immunology / Q000378:metabolism*; D000951:Antigens, Neoplasm; D015415:Biomarkers; D003228:Conjunctiva / Q000378:metabolism* / Q000473:pathology; D015352:Dry Eye Syndromes / Q000378:metabolism* / Q000473:pathology; D004847:Epithelial Cells / Q000378:metabolism* / Q000473:pathology; D019573:Epithelium, Corneal / Q000378:metabolism* / Q000473:pathology; D000939:Epitopes / Q000276:immunology / Q000378:metabolism; D005260:Female; D006023:Glycoproteins / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018396:Mucin-1; D009077:Mucins / Q000276:immunology / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D000941:Antigens; D000951:Antigens, Neoplasm; D015415:Biomarkers; D000939:Epitopes; D006023:Glycoproteins; C060192:MUC1 protein, human; D018396:Mucin-1; D009077:Mucins