title: Engineered cationic antimicrobial peptide (eCAP) prevents Pseudomonas aeruginosa biofilm growth on airway epithelial cells.
abstract: Chronic infections with the opportunistic pathogen Pseudomonas aeruginosa are responsible for the majority of the morbidity and mortality in patients with cystic fibrosis (CF). While P. aeruginosa infections may initially be treated successfully with standard antibiotics, chronic infections typically arise as bacteria transition to a biofilm mode of growth and acquire remarkable antimicrobial resistance. To address the critical need for novel antimicrobial therapeutics that can effectively suppress chronic bacterial infections in challenging physiological environments, such as the CF lung, we have rationally designed a de novo engineered cationic antimicrobial peptide, the 24-residue WLBU2, with broad-spectrum antibacterial activity for pan-drug-resistant P. aeruginosa in liquid culture. In the current study, we tested the hypothesis that WLBU2 also prevents P. aeruginosa biofilm growth.
  
  
  
  Using abiotic and biotic biofilm assays, co-culturing P. aeruginosa with polarized human airway epithelial cells, we examined the ability of WLBU2 to prevent biofilm biogenesis alone and in combination with currently used antibiotics.
  
  
  
  We observed a dose-dependent reduction in biofilm growth on an abiotic surface and in association with CF airway epithelial cells. WLBU2 prevented P. aeruginosa biofilm formation when co-cultured with mucus-producing primary human CF airway epithelial cells and using CF clinical isolates of P. aeruginosa, even at low pH and high salt conditions that mimic the CF airway. When used in combination, WLBU2 significantly increases killing by the commonly used antibiotics tobramycin, ciprofloxacin, ceftazidime and meropenem.
  
  
  
  While other studies have demonstrated the ability of natural and synthetic antimicrobial peptides to prevent abiotic bacterial biofilm formation, the current studies for the first time demonstrate the effective peptide treatment of a biotic bacterial biofilm in a setting similar to the CF airway, and without negative effects on human airway epithelial cells, thus highlighting the unique potential of this engineered cationic antimicrobial peptide for treatment of human respiratory infections.
authors.affiliation: Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Lauren P
authors.initials: LP
authors.lastname: Lashua
authors.affiliation: Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Melvin
authors.affiliation: Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, USA Center for Vaccine Research, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Berthony
authors.initials: B
authors.lastname: Deslouches
authors.affiliation: Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Pilewski
authors.affiliation: Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, USA Center for Vaccine Research, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Ronald C
authors.initials: RC
authors.lastname: Montelaro
authors.affiliation: Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, USA jbomb@pitt.edu.
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Bomberger
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000235:genetics / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D002460:Cell Line; D018920:Coculture Techniques; D004847:Epithelial Cells / Q000382:microbiology*; D006801:Humans; D015202:Protein Engineering; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000502:physiology; D011994:Recombinant Proteins / Q000235:genetics / Q000494:pharmacology*
chemical_list: D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides; D011994:Recombinant Proteins