A Monoclonal Antibody Specific for Japanese Encephalitis Virus with High Neutralizing Capability for Inclusion as a...

Area of Science:

• Virology
• Immunology
• Public Health

Background:

• Japanese encephalitis virus (JEV) is a leading cause of viral encephalitis in Asia, posing a growing global health risk due to its expanding geographic range.
• Despite available vaccines, JEV infections remain prevalent, with over 60,000 cases reported annually, highlighting the need for improved diagnostic tools.

Purpose of the Study:

• To develop a reproducible and specific positive control antibody for diagnosing Japanese encephalitis virus infections.
• To characterize the neutralizing capabilities and epitope mapping of newly developed monoclonal antibodies against JEV.

Main Methods:

• Murine hybridomas were generated using a combination of IXIARO JEV vaccine and JEV envelope protein domain III (E-DIII).
• Monoclonal antibodies (MAbs) were screened for JEV specificity and in vitro virus neutralization activity.
• Plaque reduction neutralization tests (PRNT) were performed to determine neutralizing titers, and functional epitopes were mapped using virus neutralization escape variants.

Main Results:

• Monoclonal antibody 17BD3-2 demonstrated high specificity for JEV and potent neutralizing activity, with a PRNT90 endpoint titer of 1.25 μg/mL.
• The functional epitopes targeted by MAb 17BD3-2 were identified at amino acid residues S309, K312, and G333 within the E-DIII region.
• This MAb proved effective in neutralizing JEV in vitro.

Conclusions:

• Monoclonal antibody 17BD3-2 is a highly effective JEV-specific neutralizing antibody.
• This antibody can serve as a valuable substitute for human immune sera as a positive control in PRNT assays for JEV diagnosis.
• The characterized MAb has the potential for global distribution to public health laboratories for JEV outbreak surveillance and diagnosis.