title: Characterization of Langerin-expressing dendritic cell subsets in the normal cornea.
abstract: OBJECTIVE
  In addition to Langerhans cells (LCs), other dendritic cells (CD11c(+)) have recently been shown to express Langerin (c-type lectin). In skin, (non-LC) Langerin+ dendritic cells initiate adaptive immunity. However, whether such dendritic cells (DC) reside in the cornea, an immune-privileged tissue, is unknown.
  
  
  METHODS
  Normal C57BL/6 corneas were harvested for qRT-PCR analyses of Langerin expression in the epithelium versus stroma. Immunohistochemistry for Langerin was also performed. Single-cell preparations of epithelium versus stroma were FACS analyzed for CD11c, CD11b, and CD103 expression. Fluorescence microscopy of corneas from muLangerin-eGFP mice (in which all CD11c(+) Langerin+ cells express eGFP), huLangerin-DTA mice (only LCs are constitutively deleted), and huLangerin-Cre eYFP-flox (only LCs express eYFP) was performed.
  
  
  RESULTS
  qRT-PCR, immunohistochemistry, and FACS analysis identified CD11c(+) Langerin+ cells in the epithelium and stroma. Similarly, corneas of muLangerin-eGFP mice contained eGFP+ cells in the epithelium and stroma. However, FACS analysis indicated phenotypically differing CD11c(+) Langerin+ populations in the epithelium (CD11b(low)CD103(low)) versus stroma (CD11b(+)CD103(low)). Additionally, corneas from huLangerin-DTA mice were devoid of Langerin+ cells in the epithelium but were detectable in the stroma. In corneas from huLangerin-Cre eYFP-flox, eYFP+ cells were detectable in the epithelium but not in the stroma.
  
  
  CONCLUSIONS
  The normal corneal epithelium is endowed with CD11c(+) Langerin+ cells that are LCs, whereas the stroma is endowed with a separate population of (non-LC) Langerin+ DCs. These findings should henceforth facilitate the examination of Langerin-expressing DC subsets in the immunopathogeneses of conditions such as keratoconjunctivitis sicca, allergic keratoconjunctivitis, and corneal allograft rejection.
authors.affiliation: Schepens Eye Research Institute, Boston, Massachusetts 02117, USA.
authors.forename: Takaaki
authors.initials: T
authors.lastname: Hattori
authors.forename: Sunil K
authors.initials: SK
authors.lastname: Chauhan
authors.forename: Hyunsoo
authors.initials: H
authors.lastname: Lee
authors.forename: Hiroki
authors.initials: H
authors.lastname: Ueno
authors.forename: Reza
authors.initials: R
authors.lastname: Dana
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Kaplan
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Saban
mesh_terms: D000818:Animals; D000954:Antigens, Surface / Q000096:biosynthesis / Q000235:genetics*; D003315:Cornea / Q000166:cytology* / Q000378:metabolism; D003319:Corneal Stroma / Q000166:cytology / Q000378:metabolism; D003713:Dendritic Cells / Q000166:cytology / Q000378:metabolism*; D005434:Flow Cytometry; D005786:Gene Expression Regulation; D007150:Immunohistochemistry; D037181:Lectins, C-Type / Q000096:biosynthesis / Q000235:genetics*; D008297:Male; D037241:Mannose-Binding Lectins / Q000096:biosynthesis / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D008856:Microscopy, Fluorescence; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics*
chemical_list: D000954:Antigens, Surface; C498497:Cd207 protein, mouse; D037181:Lectins, C-Type; D037241:Mannose-Binding Lectins; D012333:RNA, Messenger