title: Establishment of a neutralization test involving reporter gene-expressing virus-like particles of tick-borne encephalitis virus.
abstract: Previously, a system for packaging tick-borne encephalitis virus (TBEV) subgenomic replicon RNAs into single-round infectious virus-like particles (VLPs) was developed. In the present study, VLPs were applied to measuring the levels of neutralizing antibodies against TBEV as an alternative to performing neutralization tests with live virus. As markers of VLP infection, the genes for GFP and luciferase were inserted into the TBEV replicon, which was then packaged into VLPs. The reporter genes were expressed in cells that were infected with the VLPs, and this infection was inhibited by neutralizing antibodies to TBEV. Serum samples from wild rodents were used to evaluate the neutralization test using VLPs. All the sera that were positive in the conventional neutralization test were also found to be positive in the neutralization test using VLPs, and there were highly significant correlations between the neutralization titres obtained using the native virus and those using VLPs. These results indicate that VLPs that express reporter genes represent a useful and safe alternative to conventional neutralization testing using live virus.
authors.affiliation: Laboratory of Public Health, Graduate School of Veterinary Medicine, Hokkaido University, Kita-18 Nishi-9, Kita-ku, Sapporo, Hokkaido, Japan. kyoshii@vetmed.hokudai.ac.jp
authors.forename: Kentaro
authors.initials: K
authors.lastname: Yoshii
authors.forename: Ayae
authors.initials: A
authors.lastname: Ikawa
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Chiba
authors.forename: Yuki
authors.initials: Y
authors.lastname: Omori
authors.forename: Junko
authors.initials: J
authors.lastname: Maeda
authors.forename: Ryo
authors.initials: R
authors.lastname: Murata
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kariwa
authors.forename: Ikuo
authors.initials: I
authors.lastname: Takashima
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D004669:Encephalitis Viruses, Tick-Borne / Q000235:genetics / Q000276:immunology*; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D009500:Neutralization Tests / Q000379:methods*; D012377:Rodentia; D022701:Virosomes
chemical_list: D000914:Antibodies, Viral; D022701:Virosomes; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D008156:Luciferases