Complement-dependent cytotoxicity assay for differentiating West Nile virus from Japanese encephalitis virus infections in horses.
A complement-dependent cytotoxicity (CDC) assay was established to measure antibodies to the West Nile virus (WNV) nonstructural protein 1 (NS1) in horses. Sera collected from a WNV-infected horse mediated lysis of WNV NS1-expressing cells in a dose-dependent manner at higher percentages than sera from a Japanese encephalitis virus (JEV)-infected horse. The percentages of specific lysis for sera diluted 1:10 to 1:80 were <19.8% (assay cutoff) for almost all of the 100 JEV-infected or uninfected horses tested, in contrast to 55 to 76% in WNV-infected horses. Experimental infection revealed that horses became anti-WNV NS1 antibody positive 10 days after WNV infection. This study demonstrated the utility of this assay for differentiating WNV from JEV infections in horses.
Department of International Health, Kobe University Graduate School of Health Sciences, Kobe, Japan.
Yoko
Y
Kitai
Takashi
T
Kondo
Eiji
E
Konishi
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D003165:Complement System Proteins / Q000276:immunology*; D003601:Cytotoxicity Tests, Immunologic / Q000379:methods*; D003937:Diagnosis, Differential; D004664:Encephalitis Virus, Japanese / Q000276:immunology; D004672:Encephalitis, Japanese / Q000175:diagnosis / Q000662:veterinary*; D006734:Horse Diseases / Q000175:diagnosis* / Q000821:virology; D006736:Horses; D012680:Sensitivity and Specificity; D014901:West Nile Fever / Q000175:diagnosis / Q000662:veterinary*; D014902:West Nile virus / Q000276:immunology
D000914:Antibodies, Viral; D003165:Complement System Proteins