An indirect sandwich ELISA utilising F(ab’)2 fragments for the detection of African horsesickness virus.

The article describes the development of a novel sandwich enzyme-linked immunosorbent assay (ELISA) using F(ab’)2 fragments for quick detection of African Horsesickness Virus (AHSV) in both animal tissues and cell culture fluids.

Development of the ELISA for AHSV Detection

• The research focuses on creating an ELISA tool for diagnosing AHSV due to its destructive impact on equines and the urgent need for containment.
• This ELISA uses F(ab’)2 fragments that are a result of the pepsin-digested, AHSV-specific IgG proteins. These fragments serve to trap the virus present in tissue homogenates or cell culture supernatant.
• The trapped viruses are subsequently detected by introducing intact IgG antibodies, followed by using Staphylococcus aureus protein A labelled with horseradish peroxidase for reaction visualisation.

Testing and Results

• This newly developed ELISA effectively identifies all known AHSV serotypes when tested with polyclonal antisera against full virus particles or viral cores.
• The detecting antibodies for this experiment were polyclonal antibodies directed towards the full AHSV or viral core particles. A weakened signal was observed with a monoclonal antibody specific for one major protein, VP7.
• The immunoprecipitation of AHSV structural polypeptides affirmed that these antisera contain antibodies against the core proteins.

Significance and Future Implications

• The F(ab’)2-ELISA proves to be useful in diagnosing AHSV infections rapidly, a significant stride in controlling and preventing the spread of a major equine disease.

The research further encourages the use of F(ab’)2 fragments in ELISA tests for virus detection. However, future studies may seek to increase the effectiveness of all antibody types in these diagnostic methods.