title: Expression of Toll-like receptors in healthy and allergic conjunctiva.
abstract: OBJECTIVE
  To investigate the expression of toll-like receptors (TLRs) in healthy and active vernal keratoconjunctivitis (VKC) conjunctiva.
  
  
  METHODS
  Comparative nonrandomized interventional study.
  
  
  METHODS
  Nine patients with vernal keratoconjunctivitis and 10 healthy subjects.
  
  
  METHODS
  Normal and VKC conjunctiva were evaluated for TLR-2, TLR-4, and TLR-9 mRNA and proteins by relative real-time polymerase chain reaction and immunohistochemistry. Colocalization of TLRs was further evaluated by confocal microscopy and double-labeled immunofluorescence in T cells (CD4), mast cells (AA1), and eosinophils (EG2).
  
  
  METHODS
  Identification of TLRs at molecular and biochemical levels and identification of inflammatory cells that coexpress these receptors.
  
  
  RESULTS
  Toll-like receptor 2, TLR-4, and TLR-9 were expressed in normal and VKC conjunctival epithelium and stroma, both with a more intense immunoreactivity in the stroma. In VKC tissues, TLR-4 was upregulated, TLR-9 was downregulated, and TLR-2 was slightly decreased relative to normal tissues. Toll-like receptor 4 was localized on CD4+ lymphocytes, eosinophils, and mast cells, whereas lymphocytes and eosinophils, but not mast cells, expressed TLR-9.
  
  
  CONCLUSIONS
  Toll-like receptors are expressed in healthy and allergic conjunctiva. The upregulation or downregulation of these receptors and their presence on inflammatory cells suggest a role of TLRs in VKC.
authors: CIR Laboratory of Ophthalmology, Campus Bio-Medico and G. B. Bietti Eye Foundation, Rome, Italy. s.bonini@unicampus.it
authors: Stefano
authors: S
authors: Bonini
authors: Alessandra
authors: A
authors: Micera
authors: Alfonso
authors: A
authors: Iovieno
authors: Alessandro
authors: A
authors: Lambiase
authors: Sergio
authors: S
authors: Bonini
mesh_terms: D000293:Adolescent; D000328:Adult; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D003228:Conjunctiva / Q000378:metabolism*; D003233:Conjunctivitis, Allergic / Q000378:metabolism*; D004804:Eosinophils / Q000276:immunology; D004848:Epithelium / Q000378:metabolism; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008407:Mast Cells / Q000276:immunology; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D018613:Microscopy, Confocal; D012333:RNA, Messenger / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D051217:Toll-Like Receptor 9; D051193:Toll-Like Receptors; D015854:Up-Regulation
chemical_list: D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; C495342:TLR2 protein, human; C495345:TLR4 protein, human; C495371:TLR9 protein, human; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D051217:Toll-Like Receptor 9; D051193:Toll-Like Receptors