title: An immunoproteomic approach for identification of clinical biomarkers for monitoring disease: application to cystic fibrosis.
abstract: Circulating antibodies can be used to probe protein arrays of body fluids, prepared by two-dimensional gel electrophoresis, for antigenic biomarker detection. However, detected proteins, particularly low abundance antigens, often remain unidentifiable due to proteome complexity and limiting sample amounts. Using a novel enrichment approach exploiting patient antibodies for isolation of antigenic biomarkers, we demonstrate how immunoproteomic strategies can accelerate biomarker discovery. Application of this approach as a means of identifying biomarkers was demonstrated for cystic fibrosis (CF) lung disease by isolation and identification of inflammatory-associated autoantigens, including myeloperoxidase and calgranulin B from sputum of subjects with CF. The approach was also exploited for isolation of proteins expressed by the Pseudomonas aeruginosa strain PA01. Capture of PA01 antigens using circulating antibodies from CF subjects implicated in vivo expression of Pseudomonas proteins. All CF subjects screened, but not controls, were immunoreactive against immunocaptured Pseudomonas proteins, representing stress (GroES and ferric iron-binding protein HitA), immunosuppressive (thioredoxin), and alginate synthetase pathway (nucleoside-diphosphate kinase) proteins, implicating their clinical relevance as biomarkers of infection.
authors.affiliation: Proteome Systems Ltd., 1/35-41 Waterloo Road, North Ryde, New South Wales 2113, Australia. sanne.pedersen@proteomesystems.com
authors.forename: Susanne K
authors.initials: SK
authors.lastname: Pedersen
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Sloane
authors.forename: Sindhu S
authors.initials: SS
authors.lastname: Prasad
authors.forename: Lucille T
authors.initials: LT
authors.lastname: Sebastian
authors.forename: Robyn A
authors.initials: RA
authors.lastname: Lindner
authors.forename: Michael
authors.initials: M
authors.lastname: Hsu
authors.forename: Michael
authors.initials: M
authors.lastname: Robinson
authors.forename: Peter T
authors.initials: PT
authors.lastname: Bye
authors.forename: Ron P
authors.initials: RP
authors.lastname: Weinberger
authors.forename: Jenny L
authors.initials: JL
authors.lastname: Harry
mesh_terms: D000293:Adolescent; D000328:Adult; D000464:Alginates / Q000378:metabolism; D001324:Autoantigens / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism*; D003550:Cystic Fibrosis / Q000378:metabolism*; D015180:Electrophoresis, Gel, Two-Dimensional; D005838:Genotype; D020723:Glucuronic Acid / Q000378:metabolism; D006603:Hexuronic Acids / Q000378:metabolism; D006801:Humans; D008875:Middle Aged; D040901:Proteomics; D011550:Pseudomonas aeruginosa / Q000378:metabolism; D013183:Sputum / Q000737:chemistry
chemical_list: D000464:Alginates; D001324:Autoantigens; D001426:Bacterial Proteins; D015415:Biomarkers; D006603:Hexuronic Acids; D020723:Glucuronic Acid