Antigenic structure of the Murray Valley encephalitis virus E glycoprotein

Area of Science:

• Virology
• Immunology
• Molecular Biology

Background:

• St. Louis encephalitis (SLE) virus and Murray Valley encephalitis (MVE) virus belong to the same serocomplex.
• Monoclonal antibodies (MAbs) are crucial tools for studying viral antigens and developing diagnostics and therapeutics.
• Existing MAbs against SLE virus prompted the investigation of MVE virus-specific antibodies.

Purpose of the Study:

• To isolate and characterize MAbs that react with MVE virus.
• To compare the antigenic epitopes of MVE virus with those of SLE virus.
• To identify MVE virus-specific epitopes involved in viral neutralization and protection.

Main Methods:

• Isolation and characterization of hybridomas producing MAbs against MVE virus.
• Epitope mapping using a panel of SLE and MVE virus MAbs.
• Assessment of virus-neutralizing and protective capabilities of MAbs in animal models.

Main Results:

• Ten stable hybridomas producing MAbs against MVE virus were established.
• Eight distinct epitopes on the MVE virus envelope (E) glycoprotein were defined.
• Six epitopes were shared with SLE virus, while two new epitopes (E-5 and E-6) were identified on MVE virus.
• The MVE E-1c epitope showed potent virus-neutralizing and protective activity, similar to SLE virus.
• A cross-reactive epitope (E-5) elicited neutralizing antibodies and protected against MVE virus challenge, a novel finding.

Conclusions:

• Antigenic domains within the SLE virus serocomplex are highly conserved.
• Specific epitopes involved in virus neutralization and protection can differ between MVE and SLE viruses.
• The identification of novel, cross-reactive neutralizing epitopes offers potential targets for MVE virus-specific interventions.