Production and characterization of monoclonal antibodies against a local isolate of classical swine fever virus.

Monoclonal antibodies (mAbs) against a classical swine fever virus (CSFV; subgenogroup 1:1) isolate from Assam, India were produced and characterized. Four fusions of myeloma cells (SP2/0Ag) were made with spleenocytes of 8-10 weeks old BALB/C mice immunized with the viral antigen. Several hybridoma clones secreting antibodies to the virus were obtained after four fusions, but five hybridoma clones secreting antibody specific to the virus could be stabilized. All the mAbs belong to the IgG2a isotype. Except one, none of the four mAbs showed cross reaction with bovine viral diarrhoea virus and border disease virus (BDV). One mAb showed cross reaction with BDV. All the four mAbs specific to CSFV showed reactivity with the parental virus in immunoperoxidase test (IPT) and with a single protein band (molecular weight 55 kD approximately) of the virus in western blotting. In neutralization peroxidase linked assay (NPLA) all the mAbs reacted with 13 CSFV local isolates as well as with the cell culture adapted lapinized vaccine virus strain belonging to the subgenogroup 1:1. This is the first report on production and characterization of mAbs against CSFV in India.