title: Expression and antimicrobial function of bactericidal permeability-increasing protein in cystic fibrosis patients.
abstract: In cystic fibrosis (CF), the condition limiting the prognosis of affected children is the chronic obstructive lung disease accompanied by chronic and persistent infection with mostly mucoid strains of Pseudomonas aeruginosa. The majority of CF patients have antineutrophil cytoplasmic antibodies (ANCA) primarily directed against the bactericidal permeability-increasing protein (BPI) potentially interfering with antimicrobial effects of BPI. We analyzed the expression of BPI in the airways of patients with CF. In their sputum samples or bronchoalveolar lavage specimens, nearly all patients expressed BPI mRNA and protein, which were mainly products of neutrophil granulocytes as revealed by intracellular staining and subsequent flow cytometry. Repeated measurements revealed consistent individual BPI expression levels during several months quantitatively correlating with interleukin-8. In vitro, P. aeruginosa isolates from CF patients initiated the rapid release of BPI occurring independently of protein de novo syntheses. Furthermore, purified natural BPI as well as a 27-mer BPI-derived peptide displayed antimicrobial activity against even patient-derived mucoid P. aeruginosa strains and bacteria resistant against all antibiotics tested. Thus, BPI that is functionally active against mucoid P. aeruginosa strains is expressed in the airways of CF patients but may be hampered by autoantibodies, resulting in chronic infection.
authors.affiliation: Institut für Klinische Mikrobiologie, Immunologie und Hygiene der Universität Erlangen-Nürnberg, Wasserturmstr. 3, D-91054 Erlangen, Germany.
authors.forename: Diana
authors.initials: D
authors.lastname: Aichele
authors.forename: Markus
authors.initials: M
authors.lastname: Schnare
authors.forename: Marc
authors.initials: M
authors.lastname: Saake
authors.forename: Martin
authors.initials: M
authors.lastname: Röllinghoff
authors.forename: Andre
authors.initials: A
authors.lastname: Gessner
mesh_terms: D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides; D001798:Blood Proteins / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*; D003550:Cystic Fibrosis / Q000378:metabolism / Q000382:microbiology*; D006801:Humans; D008171:Lung Diseases / Q000378:metabolism / Q000382:microbiology; D008565:Membrane Proteins / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*; D008969:Molecular Sequence Data; D009504:Neutrophils / Q000378:metabolism; D011552:Pseudomonas Infections / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000187:drug effects*; D013183:Sputum / Q000276:immunology / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D001798:Blood Proteins; D008565:Membrane Proteins; C021623:bactericidal permeability increasing protein