Development and biological characterization of monoclonal antibody with neutralization activity against GP5 protein of porcine reproduction and respiratory syndrome virus

To prepare monoclonal antibodies(McAb)against GP5 protein of porcine reproduction and respiratory syndrome virus(PRRSV),the plasmid encoding GP5 gene of PRRSV-S1 strain was used.BALB/c mice were immunized by subcutaneous injection.The induced spleen cells were fused with SP2/0.The McAbs anti-GP5 were obtained by screening with indirect ELISA and subcloned 4 times,and were preliminarily characterized.Three hybridoma cell strains steadily secreting monoclonal antibodies against GP5 protein of PRRSV were obtained,which were separately named 4C9,5D10 and 5F12.The isotype of the 5D10 was IgM.The ascites titers of PRRSV-specific ELISA antibodies obtained by mice were 1∶3 200 to 1∶10 240.Relative affinity of 5D10 was tighter than that of 5F12.It indicated that these McAbs were against different regions of GP5 protein of PRRSV.Moreover,the McAbs 5D10 and 5F12 had PRRSV-specific neutralization activity.The titers of the neutralizing antibodies were 1∶40 and 1∶80.Two monoclonal antibodies having virus neutralizing activity to GP5 protein of PRRSV were made in this study.It should be very useful to diagnose and prevent PRRSV infection.