Development of a blocking ELISA using a recombinant glycoprotein for the detection of antibodies to vesicular stomatitis New Jersey virus.

The research involves the development and testing of an Enzyme-linked Immunosorbent Assay (ELISA) that uses a new recombinant protein for the detection of antibodies to vesicular stomatitis New Jersey virus (VSV-NJ), a disease affecting livestock.

Using Recombinant Glycoprotein as Diagnostic Antigen

• The research focused on expressing a recombinant glycoprotein (R-GP) of the VSV-NJ virus in insect cells through a baculovirus system.
• The aim was to investigate its effectiveness as a diagnostic antigen in an ELISA test, instead of the currently used native GP extracted from VSV-NJ.
• The utility of this method lies in the fact it allows to avoid extraction processes from the original virus, which can be complex and resource-intensive.

Testing the R-GP ELISA

• Researchers then performed an ELISA using the R-GP antigen.
• A cut-off point for detection was set at 73% inhibition.
• Test results presented a 99.1% specificity when the R-GP ELISA was used with naive cattle and horse sera, implying a high degree of accuracy in detecting VSV-NJ antibodies.

Evaluating Cross-Reaction and Differentiation

• The team needed to evaluate whether the R-GP ELISA could correctly distinguish between different diseases with similar symptoms or related causes, a crucial requirement for any diagnostic tool.
• The newly developed R-GP based ELISA proved successful in not cross-reacting with sera positive for VSV-Indiana (VSV-IN), a distinct albeit related virus.
• Furthermore, the assay was able to differentiate between vesicular stomatitis, foot-and-mouth disease, and swine vesicular disease – all conditions that can affect livestock.

Conclusion

• The study concludes that the R-GP antigen showed potential to replace the native GP in detecting antibodies to the VSV-NJ virus in cattle and horses.
• This research marks the first report of R-GP’s diagnostic use, outlining a promising new approach for more precise and efficient infection diagnosis in livestock.