title: Effects of influenza A nucleoprotein on polymorphonuclear neutrophil function.
abstract: Infection with influenza virus is commonly associated with polymorphonuclear neutrophil (PMNL) dysfunction and consequent secondary bacterial pneumonia. A recently isolated human-derived protein that inhibits PMNL chemotaxis and oxidant production shows a striking homology to the influenza A nucleoprotein. In the present study, the effects of purified influenza A nucleoprotein on PMNL chemotaxis, oxidant production, degranulation, and calcium homeostasis were studied. Results of the study demonstrate that purified nucleoprotein inhibits PMNL chemotaxis as well as superoxide production. In addition, purified nucleoprotein induces a rise in PMNL cytosolic calcium concentration in a manner similar to that demonstrated for crude influenza A lysates. In contrast, no difference in FMLP-stimulated PMNL elastase or beta glucuronidase release was noted after exposure to nucleoprotein. These studies suggest that the influenza A nucleoprotein may account for some of the neutrophil defect associated with cellular infection by this virus.
authors.affiliation: Pulmonary Sections, Birmingham VA Medical Center, Alabama, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Cooper
authors.forename: R
authors.initials: R
authors.lastname: Carcelen
authors.forename: R
authors.initials: R
authors.lastname: Culbreth
mesh_terms: D002118:Calcium / Q000378:metabolism; D015550:Cell Degranulation / Q000187:drug effects; D002634:Chemotaxis, Leukocyte / Q000187:drug effects* / Q000502:physiology; D004591:Electrophoresis, Polyacrylamide Gel; D005966:Glucuronidase / Q000378:metabolism; D006801:Humans; D009980:Influenza A virus / Q000737:chemistry*; D019272:Leukocyte Elastase; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects* / Q000502:physiology; D019590:Nucleocapsid Proteins; D009698:Nucleoproteins / Q000302:isolation & purification / Q000494:pharmacology*; D010196:Pancreatic Elastase / Q000378:metabolism; D016601:RNA-Binding Proteins; D013481:Superoxides / Q000378:metabolism; D014758:Viral Core Proteins / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: C048842:NP protein, Influenza A virus; D019590:Nucleocapsid Proteins; D009698:Nucleoproteins; D016601:RNA-Binding Proteins; D014758:Viral Core Proteins; D013481:Superoxides; D009240:N-Formylmethionine Leucyl-Phenylalanine; D005966:Glucuronidase; D010196:Pancreatic Elastase; D019272:Leukocyte Elastase; D002118:Calcium