scholarly journals A Functional Epitope Determinant on Domain III of the Japanese Encephalitis Virus Envelope Protein Interacted with Neutralizing-Antibody Combining Sites

2003 ◽  
Vol 77 (4) ◽  
pp. 2600-2606 ◽  
Author(s):  
Cheng-Wen Lin ◽  
Suh-Chin Wu
Keyword(s):  
Japanese Encephalitis Virus ◽  
Japanese Encephalitis ◽  
Spatial Configuration ◽  
Neutralizing Antibody ◽  
Encephalitis Virus ◽  
Molecular Structures ◽  
Site Directed Mutagenesis ◽  
Virus Envelope ◽  
E Protein ◽  
Domain Iii

ABSTRACT The envelope (E) protein of Japanese encephalitis virus (JEV) is associated with viral binding to cellular receptors, membrane fusion, and the induction of protective neutralizing-antibody responses in hosts. Most previous studies have not provided detailed molecular information about the spatial configuration of the functional epitopes on domain III of the E protein. Here site-directed mutagenesis was performed to demonstrate that the functional epitope determinants at Ser331 and Asp332 on domain III of the JEV E protein interacted with neutralizing monoclonal antibody (MAb) E3.3. Bacterial expression of the recombinant Fab E3.3 confirmed the molecular interactions of Arg94 in complementary determining region H3 with Ser331 and Asp332 on domain III. This study elucidates the detailed molecular structures of the neutralizing epitope determinants on JEV domain III, which can provide useful information for designing new vaccines.

scholarly journals Mutation analysis of the cross-reactive epitopes of Japanese encephalitis virus envelope glycoprotein

2012 ◽  
Vol 93 (6) ◽  
pp. 1185-1192 ◽  
Author(s):  
Shyan-Song Chiou ◽  
Yi-Chin Fan ◽  
Wayne D. Crill ◽  
Ruey-Yi Chang ◽  
Gwong-Jen J. Chang
Keyword(s):  
Amino Acid ◽  
Japanese Encephalitis Virus ◽  
Japanese Encephalitis ◽  
Recombinant Expression ◽  
Encephalitis Virus ◽  
Site Directed Mutagenesis ◽  
Amino Acid Residues ◽  
Virus Envelope ◽  
E Protein ◽  
Domain Iii

Group and serocomplex cross-reactive epitopes have been identified in the envelope (E) protein of several flaviviruses and have proven critical in vaccine and diagnostic antigen development. Here, we performed site-directed mutagenesis across the E gene of a recombinant expression plasmid that encodes the Japanese encephalitis virus (JEV) premembrane (prM) and E proteins and produces JEV virus-like particles (VLPs). Mutations were introduced at I135 and E138 in domain I; W101, G104, G106 and L107 in domain II; and T305, E306, K312, A315, S329, S331, G332 and D389 in domain III. None of the mutant JEV VLPs demonstrated reduced activity to the five JEV type-specific mAbs tested. Substitutions at W101, especially W101G, reduced reactivity dramatically with all of the flavivirus group cross-reactive mAbs. The group and JEV serocomplex cross-reactive mAbs examined recognized five and six different overlapping epitopes, respectively. Among five group cross-reactive epitopes, amino acids located in domains I, II and III were involved in one, five and three epitopes, respectively. Recognition by six JEV serocomplex cross-reactive mAbs was reduced by amino acid substitutions in domains II and III. These results suggest that amino acid residues located in the fusion loop of E domain II are the most critical for recognition by group cross-reactive mAbs, followed by residues of domains III and I. The amino acid residues of both domains II and III of the E protein were shown to be important in the binding of JEV serocomplex cross-reactive mAbs.

scholarly journals Immunological Analysis of Nodavirus Capsid Displaying the Domain III of Japanese Encephalitis Virus Envelope Protein

Pharmaceutics ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1826
Author(s):  
Kiven Kumar ◽  
Hui Kian Ong ◽  
Wen Siang Tan ◽  
Siti Suri Arshad ◽  
Kok Lian Ho
Keyword(s):  
T Lymphocytes ◽  
Immune Responses ◽  
Nk Cells ◽  
Japanese Encephalitis Virus ◽  
Cytotoxic T Lymphocytes ◽  
Japanese Encephalitis ◽  
Envelope Protein ◽  
Encephalitis Virus ◽  
Virus Envelope ◽  
Domain Iii

Japanese encephalitis virus (JEV) is the pathogen that causes Japanese encephalitis (JE) in humans and horses. Lethality of the virus was reported to be between 20–30%, of which, 30–50% of the JE survivors develop neurological and psychiatric sequelae. Attributed to the low effectiveness of current therapeutic approaches against JEV, vaccination remains the only effective approach to prevent the viral infection. Currently, live-attenuated and chimeric-live vaccines are widely used worldwide but these vaccines pose a risk of virulence restoration. Therefore, continuing development of JE vaccines with higher safety profiles and better protective efficacies is urgently needed. In this study, the Macrobrachium rosenbergii nodavirus (MrNV) capsid protein (CP) fused with the domain III of JEV envelope protein (JEV-DIII) was produced in Escherichia coli. The fusion protein (MrNV-CPJEV-DIII) assembled into virus-like particles (VLPs) with a diameter of approximately 18 nm. The BALB/c mice injected with the VLPs alone or in the presence of alum successfully elicited the production of anti-JEV-DIII antibody, with titers significantly higher than that in mice immunized with IMOJEV, a commercially available vaccine. Immunophenotyping showed that the MrNV-CPJEV-DIII supplemented with alum triggered proliferation of cytotoxic T-lymphocytes, macrophages, and natural killer (NK) cells. Additionally, cytokine profiles of the immunized mice revealed activities of cytotoxic T-lymphocytes, macrophages, and NK cells, indicating the activation of adaptive cellular and innate immune responses mediated by MrNV-CPJEV-DIII VLPs. Induction of innate, humoral, and cellular immune responses by the MrNV-CPJEV-DIII VLPs suggest that the chimeric protein is a promising JEV vaccine candidate.

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