title: Characterization of dendritic cell phenotype in allergic conjunctiva: increased expression of Fc(epsilon)RI, the high-affinity receptor for immunoglobulin E.
abstract: OBJECTIVE
  Dendritic cells (DCs) express the high-affinity receptor for IgE (Fc(epsilon)RI) on their surface, which may enhance their ability to capture and internalize antigens for presentation to T-lymphocytes. The aim of this study was to determine if expression of Fc(epsilon)RI(+) DCs is increased in the conjunctivae of vernal keratoconjunctivitis (VKC) patients compared with those of normal controls.
  
  
  METHODS
  Conjunctival biopsies were obtained from non-atopic and VKC patients. Double immunohistochemical staining was carried out using antibodies against Fc(epsilon)RI and the CD1a antigen, a DC marker. The double-positive cells were counted in five representative fields of view for each conjunctival sample.
  
  
  RESULTS
  Fc(epsilon)RI(+) CD1a(+) cells were present in significantly higher numbers in VKC conjunctivae compared with normal controls (mean cell count of 21.3 in VKC vs5.0 in controls, P<0.005). In normal patients the Fc(epsilon)RI-expressing DCs tended to be confined to the epithelial layer or the superficial substantia propria, but in the VKC samples these Fc(epsilon)RI(+) cells were mainly concentrated in the deeper substantia propria.
  
  
  CONCLUSIONS
  Fc(epsilon)RI(+) DC numbers are elevated in the conjunctivae of VKC patients, a finding consistent with the results of other studies focusing on atopic conditions. Elevated expression of Fc(epsilon)RI on DCs would facilitate antigen presentation and enhance T-cell priming, thereby contributing to ocular symptoms.
authors.affiliation: UCL, Institute of Ophthalmology, London, UK. b.manzouri@ucl.ac.uk
authors.forename: B
authors.initials: B
authors.lastname: Manzouri
authors.forename: M
authors.initials: M
authors.lastname: Ohbayashi
authors.forename: A
authors.initials: A
authors.lastname: Leonardi
authors.forename: D F P
authors.initials: DF
authors.lastname: Larkin
authors.forename: S J
authors.initials: SJ
authors.lastname: Ono
mesh_terms: D003228:Conjunctiva / Q000378:metabolism; D003233:Conjunctivitis, Allergic / Q000378:metabolism*; D003713:Dendritic Cells / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D010641:Phenotype; D017455:Receptors, IgE / Q000378:metabolism*
chemical_list: D017455:Receptors, IgE