Development of a monoclonal antibody that is specific for the Rabies virus phosphoprotein

Objective: To develop a monoclonal antibodies against Rabies virus phosphoprotein (P), which has conserved domains, and such regions are potentially interesting targets for the diagnosis. Methodes: In the study, a rabies virus p gene coding for the rabies virus phosphoprotein was amplified by PCR and cloned into the expression vector pET32a (+). The recombinant protein was expressed in Escherichia coli, purified with a HisTrap FF crude prepacked column and used to produce mouse monoclonal antibodies (Mabs). The anti-P Mabs were purified and their specificity was tested by indirect ELISA. One specific Mab was further tested by Western blotting against recombinant P and immunofluorescence analysis on cell monolayers infected with rabies virus. Results: The recombinant viral phosphoprotein was successfully expressed as a 53.8 kDa fusion protein which corresponded to the whole protein of the rabies virus. Of the Mabs that were generated, one (4B5) was shown to be highly specific, and could be used to detect recombinant P and native P in the whole virus. Conclusion: The use of a P protein obtained from heterologous expression in E. coli allowed the development of a Mab that interacted specifically with the P protein. This Mab should be useful for future studies with the rabies virus.