Novel JEV antigen

CLINICAL AND VACCINE IMMUNOLOGY, May 2008, p. 825–835 Vol. 15, No. 5

Enzyme-Linked Immunosorbent Assays Using Novel JapaneseEncephalitis Virus Antigen Improve the Accuracy ofClinical Diagnosis of Flavivirus Infections


Shyan-Song Chiou,1 Wayne D. Crill,2 Li-Kuang Chen,3 and Gwong-Jen J. Chang2*

The cross-reactive antibodies induced by flavivirus infections confound serodiagnosis and pathogenesis,especially in secondary infections caused by antigenically closely related yet distinct flaviviruses. The envelope(E) glycoprotein fusion peptide contains immunodominant cross-reactive determinants. Using a recombinantJapanese encephalitis virus (JEV) premembrane and E expression plasmid producing JEV virus-like particles(VLPs), dramatic reductions in cross-reactivity were produced by the G106K-L107D (KD) double-mutant VLPagainst a panel of flavivirus murine monoclonal antibodies. Human serum panels from patients with recentflavivirus infections were analyzed to compare the accuracy of JEV wild-type (WT) and KD VLPs as serodiagnosticantigens in enzyme-linked immunosorbent assays. Statistical analysis demonstrated significant differencesin assay performances for accurate determination of current JEV infections between WT and KDantigens by detecting immunoglobulin M antibodies at a serum dilution of 1:4,000 (likelihood ratios
2.74[WT] and 22 [KD]). The application and continued development of cross-reactivity-reduced antigens shouldimprove both flavivirus infection serodiagnosis and estimates of disease burden.