title: Synergistic Effect of Dermatophagoides farinae and Lipopolysaccharides in Human Middle ear Epithelial Cells.
abstract: OBJECTIVE
  Although the concept of "one airway, one disease," which includes the middle ear space as part of the united airway is well recognized, the role of allergens in otitis media with effusion (OME) is not clearly understood. We aimed to investigate the effect of the interaction between Dermatophagoides farinae (Der f) and lipopolysaccharide (LPS) on the induction of epithelial inflammatory response in vitro.
  
  
  METHODS
  Primary human middle ear epithelial cells were exposed to Der f, LPS, or both in different sequences, and the magnitude of the immunologic responses was compared. The mRNA expressiona of mucin (MUC) 4, 5AC, 5B, 8, GM-CSF, TNF-α, TLR4, and MD-2 were evaluated using real-time PCR. MUC levels before and after siRNA-mediated knockout of TLR4 and MD-2 were assessed. Lastly, the involved cell signaling pathway was evaluated.
  
  
  RESULTS
  The expressiona of cytokines, and the MUC 4, 5AC, 5B, and 8 genes were augmented by pretreatment with Der f followed by LPS; however, reverse treatment or combined treatment did not induce the same magnitude of response. Increased MUC expression was decreased by TLR4 knockdown, but not by MD-2 knockdown. The signal intensity of MUC 8 was higher in MD-2 over-expressed cells than in those exposed to LPS only. The translocation of nuclear factor-κB was observed in cells pretreated with Der f followed by LPS.
  
  
  CONCLUSIONS
  When Der f treatment preceded LPS exposure, Der f and LPS acted synergistically in the induction of pro-inflammatory cytokines and the MUC gene, suggesting an important role in the development of OME in patients with concealed allergy airway sensitization.
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Chosun University College of Medicine, Gwangju, Korea.|Department of Otorhinolaryngology-Head and Neck Surgery, Graduate school of Medicine, Seoul National University, Seoul, Korea.
authors.forename: Ji Eun
authors.initials: JE
authors.lastname: Lee
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Chosun University College of Medicine, Gwangju, Korea.
authors.forename: Yeon Hoo
authors.initials: YH
authors.lastname: Kim
authors.affiliation: Sensory Organ Research Center, Seoul National University Biomedical Research Institute, Seoul, Korea.|Institute of Allergy and Clinical Immunology, Seoul National University Biomedical Research Institute, Seoul, Korea.|Graduate School of Immunology, Seoul National University, Seoul, Korea.|Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.
authors.forename: Chae Seo
authors.initials: CS
authors.lastname: Rhee
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University College of Medicine, Seoul, Korea. dongkim@snu.ac.kr.
authors.forename: Dong Young
authors.initials: DY
authors.lastname: Kim
keywords: Dermatophagoides farinae; innate immunity; lipopolysaccharides; mucins; toll-like receptors