title: Development of neuraminidase subtype-specific reference antisera by recombinant protein expressed in baculovirus.
abstract: Outbreaks of avian influenza A virus infection, particularly the H5N1 strains that have affected birds and some humans for the past 15 years, have highlighted the need for increased surveillance and disease control. Such measures require diagnostic tests to detect and characterize the different subtypes of influenza virus. In the current study, a simple method for producing reference avian influenza virus antisera to be used in diagnostic tests was developed. Antisera of nine avian influenza A virus neuraminidases (NA) used for NA subtyping were produced using a recombinant baculovirus. The recombinant NA (rNA) proteins were expressed in Sf9 insect cells and inoculated intramuscularly into specific-pathogen-free chickens with the ISA70 adjuvant. The NA inhibition antibody titers of the rNA antiserum were in the ranges of 5 to 8 and 6 to 9 log(2) units after the primary and boost immunizations, respectively. The antisera were subtype specific, showing low cross-reactivity against every other NA subtype using the conventional thiobarbituric acid NA inhibition assay. These results suggest that this simple method for producing reference NA antisera without purification may be useful for the diagnosis and surveillance of influenza virus.
authors.affiliation: Avian Disease Division, Animal, Plant and Fisheries Quarantine and Inspection Agency (QIA), Anyang City, Gyeonggi-do, Republic of Korea.
authors.forename: Kyu-Jun
authors.initials: KJ
authors.lastname: Lee
authors.forename: Jun-Gu
authors.initials: JG
authors.lastname: Choi
authors.forename: Hyun-Mi
authors.initials: HM
authors.lastname: Kang
authors.forename: Kwang-Il
authors.initials: KI
authors.lastname: Kim
authors.forename: Choi-Kyu
authors.initials: CK
authors.lastname: Park
authors.forename: Youn-Jeong
authors.initials: YJ
authors.lastname: Lee
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood / Q000276:immunology*; D016367:Baculoviridae / Q000235:genetics; D002645:Chickens / Q000276:immunology; D003429:Cross Reactions; D006385:Hemagglutination Inhibition Tests / Q000662:veterinary; D006801:Humans; D007106:Immune Sera; D053124:Influenza A Virus, H5N1 Subtype / Q000276:immunology*; D005585:Influenza in Birds / Q000175:diagnosis* / Q000276:immunology / Q000517:prevention & control; D007251:Influenza, Human / Q000175:diagnosis* / Q000276:immunology / Q000517:prevention & control; D009439:Neuraminidase / Q000145:classification / Q000235:genetics / Q000276:immunology*; D011994:Recombinant Proteins / Q000276:immunology; D061987:Sf9 Cells
chemical_list: D000914:Antibodies, Viral; D007106:Immune Sera; D011994:Recombinant Proteins; D009439:Neuraminidase