title: Polyinosine-polycytidylic acid enhances cellular adherence of Streptococcus pneumoniae.
abstract: OBJECTIVE
  Viral upper respiratory tract infections (URIs) are often followed by secondary bacterial infections. To better understand this phenomenon, we examined the impact of the viral agent polyinosine-polycytidylic acid [Poly (I:C)] on the adherence of Streptococcus pneumoniae (Spn) to pharyngeal epithelial cells.
  
  
  METHODS
  In vitro model of cultured human pharyngeal epithelial cells.
  
  
  METHODS
  Detroit 562 cells, a human pharyngeal carcinoma cell line, were pretreated with Poly (I:C). Poly (I:C)-induced expression of platelet-activating factor receptor (PAF-R) was assayed using real-time polymerase chain reaction, flow cytometry, and immunofluorescence microscopy. Bacterial adhesion to these epithelial cells was assessed using immunofluorescence microscopy and colony formation assays.
  
  
  RESULTS
  Pretreatment with Poly (I:C) increased mRNA and protein expression of PAF-R in Detroit 562 cells and enhanced the adherence of Spn to these epithelial cells.
  
  
  CONCLUSIONS
  RNA viral infection can enhance PAF-R expression in epithelial cells and increase the adherence of Spn. These findings might explain in part the mechanisms that underlie the increase in bacterial infection following URIs.
authors: Department of Otolaryngology-Head and Neck Surgery, Kagoshima University, Graduate School of Medical and Dental Science, Kagoshima, Japan. supercar@m.kufm.kagoshima-u.ac.jp
authors: Masaki
authors: M
authors: Kawabata
authors: Yuichi
authors: Y
authors: Kurono
mesh_terms: D001422:Bacterial Adhesion / Q000187:drug effects* / Q000235:genetics; D045744:Cell Line, Tumor; D060085:Coinfection / Q000382:microbiology; D015169:Colony Count, Microbial; D004847:Epithelial Cells / Q000382:microbiology*; D005434:Flow Cytometry; D006801:Humans; D066298:In Vitro Techniques; D008856:Microscopy, Fluorescence; D010614:Pharynx / Q000382:microbiology*; D010980:Platelet Membrane Glycoproteins / Q000235:genetics; D011070:Poly I-C / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D043562:Receptors, G-Protein-Coupled / Q000235:genetics; D012141:Respiratory Tract Infections / Q000382:microbiology; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000235:genetics
chemical_list: D010980:Platelet Membrane Glycoproteins; D012333:RNA, Messenger; D043562:Receptors, G-Protein-Coupled; C039351:platelet activating factor receptor; D011070:Poly I-C