title: Pseudomonas aeruginosa binds to extracellular matrix deposited by human corneal epithelial cells.
abstract: OBJECTIVE
  To measure the effect of extracellular matrix substrate, pH, and O(2) on Pseudomonas aeruginosa binding.
  
  
  METHODS
  Extracellular matrix substrates were prepared from human corneal epithelial cells cultured in 2% or 20% O(2). P. aeruginosa strains ATCC 19660 or PAO1 (suspended in pH 7.0 or 7.5 buffer) were cultured on extracellular matrix substrates in 2% or 20% O(2). The mean number of adherent bacteria per counted per field +/- SEM (n = 15) was determined for combinations of bacteria, extracellular matrix substrate, pH, and O(2). Binding in the presence of antibodies directed against laminin-5 was also measured.
  
  
  RESULTS
  Extracellular matrix substrates produced by cells cultured in 20% O(2), combined with an environment of pH 7.0, provided the least favorable conditions for binding of strain 19660. In contrast, extracellular matrix substrates produced by cells cultured in 2% O(2), combined with an environment of pH 7.0, provided the most favorable conditions for binding of strain 19660. Binding of PAO1, however, as a function of extracellular matrix substrate and pH, did not similarly compare with binding of strain 19660. Antibodies against laminin-5 chains served to increase the number of strain 19660 bacteria bound to extracellular matrix substrates compared with the control.
  
  
  CONCLUSIONS
  The extracellular matrix secreted by hypoxic corneal epithelial cells is a substrate for binding of P. aeruginosa. Results in previous studies have shown that hypoxic extracellular matrix contains less laminin-5 protein than normoxic matrix. The antibody studies in this report suggest that the decrease in laminin-5 content in hypoxic matrix, relative to matrix secreted by normoxic corneal epithelium, may be responsible for increased bacterial adhesion.
authors.affiliation: Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan 48201, USA.
authors.forename: Miechia A
authors.initials: MA
authors.lastname: Esco
authors.forename: Linda D
authors.initials: LD
authors.lastname: Hazlett
authors.forename: Michelle
authors.initials: M
authors.lastname: Kurpakus-Wheater
mesh_terms: D000293:Adolescent; D001422:Bacterial Adhesion; D015815:Cell Adhesion Molecules / Q000378:metabolism; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000378:metabolism / Q000648:ultrastructure; D019573:Epithelium, Corneal / Q000378:metabolism* / Q000382:microbiology* / Q000648:ultrastructure; D005109:Extracellular Matrix / Q000378:metabolism* / Q000382:microbiology* / Q000648:ultrastructure; D006801:Humans; D006863:Hydrogen-Ion Concentration; D000860:Hypoxia / Q000378:metabolism; D008297:Male; D008855:Microscopy, Electron, Scanning; D011550:Pseudomonas aeruginosa / Q000502:physiology* / Q000648:ultrastructure; D000097794:Kalinin
chemical_list: D015815:Cell Adhesion Molecules; D000097794:Kalinin