Monoclonal antibodies against the nucleocapsid proteins of henipaviruses: production, epitope mapping and application in immunohistochemistry.

This study explores the creation of monoclonal antibodies directed towards the nucleocapsid protein of Nipah and Hendra viruses, identifying specific antigenic sites, and their potential use in diagnosing henipaviruses infections.

Monoclonal Antibodies Production

• The researchers immunized BALB/C mice with recombinant nucleocapsid protein (N) of the Nipah virus (NiV) and Hendra virus (HeV), both of which were expressed in the bacteria E.coli.
• Four monoclonal antibodies (mAbs) were produced – two for the HeV N and two for the NiV N.

Antibodies Reactivity and Verification

• All four mAbs showed specific reactivity with the recombinant N proteins of both NiV and HeV, as identified through western blot – a common laboratory method to detect the presence of specific proteins.
• The reactivity was further confirmed through an immunofluorescent antibody assay involving fixed insect cells infected with recombinant baculoviruses that express either the HeV or NiV N protein.

Epitope Mapping

• Epitope mapping using a 12-mer random peptide phage display library uncovered two linear antigenic sites of the henipavirus N proteins, KLxR (aa 17-20) and FKREM (aa 446-450). These sites had not been reported previously.

Practical Application of mAbs

• Two of the monoclonal antibodies were effective in identifying Hendra virus antigens through the immunohistochemical staining of lung tissue sections obtained from a horse experimentally infected with HeV.
• This result indicates these mAbs could potentially be utilized as diagnostic tools in the detection of henipaviruses.

The research concluded that these monoclonal antibodies, specifically designed to recognize nucleocapsid proteins of Nipah and Hendra viruses, will significantly contribute towards further research in the immunological study of henipaviruses and provide great strides in improving their diagnosis.