title: Hemolytic phospholipase C inhibition protects lung function during Pseudomonas aeruginosa infection.
abstract: BACKGROUND
  The opportunistic pathogen Pseudomonas aeruginosa causes both acute and chronic lung infections and is particularly problematic in patients with cystic fibrosis and those undergoing mechanical ventilation. Decreased lung function contributes significantly to morbidity and mortality during P. aeruginosa infection, and damage inflicted by P. aeruginosa virulence factors contributes to lung function decline.
  
  
  OBJECTIVE
  We sought to describe direct contribution of a bacterial phospholipase C/sphingomyelinase, PlcHR, to alteration of host lung physiology and characterize a potential therapeutic for protection of lung function.
  
  
  METHODS
  We infected C57Bl/6 mice with P. aeruginosa wild-type or isogenic plcHR deletion strains and measured lung function using computer-controlled ventilators. For in vivo testing, miltefosine was delivered intraperitoneally 1 hour after infection. Infection and respiratory endpoints were at 24 hours after infection.
  
  
  RESULTS
  P. aeruginosa wild-type infection caused significant lung function impairment, whereas the effects of a ΔplcHR strain infection were much less severe. Surfactometry analysis of bronchoalveolar lavage fluid indicated that PlcHR decreased pulmonary surfactant function. Miltefosine has structural similarity to the PC and sphingomyelin substrates of PlcHR, and we found that it inhibits the cleavage of these choline-containing lipids in vitro. Miltefosine administration after P. aeruginosa infection limited the negative effects of PlcHR activity on lung function.
  
  
  CONCLUSIONS
  We have directly linked production of a single virulence factor in P. aeruginosa with effects on lung function, and demonstrated that the inhibitor miltefosine protects lung function from PlcHR-dependent surfactant dysfunction.
authors.affiliation: Department of Microbiology and Molecular Genetics, University of Vermont College of Medicine, Burlington, VT 05405, USA. Matthew.Wargo@med.uvm.edu
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Wargo
authors.forename: Maegan J
authors.initials: MJ
authors.lastname: Gross
authors.forename: Sathish
authors.initials: S
authors.lastname: Rajamani
authors.forename: Jenna L
authors.initials: JL
authors.lastname: Allard
authors.forename: Lennart K A
authors.initials: LK
authors.lastname: Lundblad
authors.forename: Gilman B
authors.initials: GB
authors.lastname: Allen
authors.forename: Michael L
authors.initials: ML
authors.lastname: Vasil
authors.forename: Laurie W
authors.initials: LW
authors.lastname: Leclair
authors.forename: Deborah A
authors.initials: DA
authors.lastname: Hogan
mesh_terms: D000818:Animals; D000935:Antifungal Agents / Q000008:administration & dosage / Q000494:pharmacology; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D003550:Cystic Fibrosis / Q000150:complications / Q000382:microbiology*; D004195:Disease Models, Animal; D006801:Humans; D007274:Injections, Intraperitoneal; D008168:Lung / Q000187:drug effects / Q000382:microbiology / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D009894:Opportunistic Infections / Q000382:microbiology; D010767:Phosphorylcholine / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000494:pharmacology; D011552:Pseudomonas Infections / Q000188:drug therapy / Q000382:microbiology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000472:pathogenicity; D012121:Respiration, Artificial / Q000009:adverse effects; D012141:Respiratory Tract Infections / Q000209:etiology* / Q000382:microbiology
chemical_list: D000935:Antifungal Agents; D010767:Phosphorylcholine; C039128:miltefosine