title: Evaluation of protein expression in bovine bronchoalveolar fluid following challenge with Mannheimia haemolytica.
abstract: Proteomics analysis of bovine bronchoalveolar fluid (BAF) following induction of pneumonia with Mannheimia haemolytica using nanoflow liquid chromatography coupled with tandem mass spectrometry (nanoLC-MS/MS) resulted in the identification of 88 unique proteins. Proteins detected in BAF included antimicrobial peptides (AMPs), complement factors, acute-phase proteins, protease inhibitors, and proteins involved in oxidation-reduction. Notwithstanding biological variation, differences in relative protein abundance, determined using normalized peptide counts, were detected for select proteins in BAF from genuinely infected versus sham-infected animals. To demonstrate the applicability of using normalized peptide counts to assess protein expression trends, LC-MS/MS data for the acute-phase protein haptoglobin (HPT) were compared with ELISA data, and statistical evaluation of the relationship between the data revealed a strong measure of association. Differences were detected between sham- and genuinely infected animals for haptoglobin, as well as the AMPs cathelicidin-1 and cathelicidin-4, and inter-α-trypsin inhibitor heavy chain-4, a fairly novel protein involved in the acute phase response. Though the small sample size limited the scope of the inferences, the results indicate the likely importance of AMPs and acute-phase proteins during respiratory infection, and provide additional information regarding potential mechanisms involved in the bovine mucosal barrier defense.
authors.affiliation: U.S. Food and Drug Administration Center for Veterinary Medicine, Laurel, MD 20708, USA. jamie.boehmer@fda.hhs.gov
authors.forename: Jamie L
authors.initials: JL
authors.lastname: Boehmer
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Degrasse
authors.forename: Vicki A
authors.initials: VA
authors.lastname: Lancaster
authors.forename: Melinda A
authors.initials: MA
authors.lastname: McFarland
authors.forename: John H
authors.initials: JH
authors.lastname: Callahan
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Ward
mesh_terms: D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry* / Q000276:immunology / Q000382:microbiology; D054804:Cathelicidins / Q000032:analysis; D002417:Cattle / Q000378:metabolism* / Q000382:microbiology; D002418:Cattle Diseases / Q000276:immunology / Q000382:microbiology; D002853:Chromatography, Liquid; D004797:Enzyme-Linked Immunosorbent Assay; D006242:Haptoglobins / Q000032:analysis; D008297:Male; D016978:Mannheimia haemolytica / Q000276:immunology / Q000472:pathogenicity*; D010446:Peptide Fragments / Q000032:analysis; D048089:Pneumonia of Calves, Enzootic / Q000276:immunology / Q000382:microbiology; D020543:Proteome / Q000032:analysis*; D040901:Proteomics; D053719:Tandem Mass Spectrometry
chemical_list: D054804:Cathelicidins; D006242:Haptoglobins; D010446:Peptide Fragments; D020543:Proteome