Enzyme-Linked Immunosorbent Assays Using Novel Japanese Encephalitis Virus Antigen Improve the Accuracy of Clinical Diagnosis of Flavivirus Infections

Graduate Institute of Veterinary Public Health, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan, Republic of China.
Clinical and vaccine Immunology: CVI (Impact Factor: 2.47). 06/2008; 15(5):825-35. DOI: 10.1128/CVI.00004-08
Source: PubMed


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 recombinant Japanese 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 VLP against a panel of flavivirus murine monoclonal antibodies. Human serum panels from patients with recent flavivirus infections were analyzed to compare the accuracy of JEV wild-type (WT) and KD VLPs as serodiagnostic antigens in enzyme-linked immunosorbent assays. Statistical analysis demonstrated significant differences in assay performances for accurate determination of current JEV infections between WT and KD antigens 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 should improve both flavivirus infection serodiagnosis and estimates of disease burden.

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Available from: Li-Kuang Chen, Jun 18, 2014
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    • "But, at the same time, various virus resistant neutralization antibodies may circulate in the blood stream, even then virus escapes the immune defense [29]. Therefore, mutation analysis of the cross-reactive epitopes of Japanese encephalitis virus envelope glycoprotein is highly essential and important to improve the accuracy of clinical diagnosis of flavivirus infections [52]. Thus, mutations generated in virus genome not only affect epitope conformational structure in antigenic binding region of protein but also affect protein folding [53]. "
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    • "Also, PL10 could successfully distinguish DENV serotypes from other flaviviruses in immunized mice sera. The high degree of antibody cross-reactivity among different flaviviruses has been a diagnostic challenge to distinguish various flaviviral infections, and this limitation is apparent for members of DENV serotypes [57,58]. It has been previously reported that prM-specific antibodies could be applied as a diagnostic marker to distinguish previous infection of DENV from JEV [22]. "
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    • "In contrast, a significant fraction of E protein-specific B cells appear to produce antibodies specific for the E-DII-FL (Throsby et al., 2006), and antibodies against this determinant are readily detected in serum. Using a similar approach, mutations in the fusion loop have improved the accuracy of serum diagnostic assays for DENV, JEV, and SLEV by eliminating detection of the highly crossreactive fusion loop antibodies (Chiou et al., 2008, and references within). As a more detailed understanding of the structural basis of antibody recognition and neutralization of flaviviruses emerges, it may be possible to generate highthroughput epitope-based diagnostic assays with a series of E protein variants that defines serotype specificity and functional classes of neutralizing antibodies after infection or vaccination. "
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