Production and characterization of monoclonal antibodies to nucleoprotein of Marburg virus.

Monoclonal antibodies (MAbs) against the nucleoprotein of Marburg virus (MARV-NP) with high specificity and activity would be useful for the diagnosis of MARV. In this report, a recombinant MARV-NP was successfully expressed by an Escherichia coli expression system. After immunization and cell fusion, three mouse hybridomas (1H4, 2G1, and 3B5) producing MAbs to MARV-NP were established. The MAbs obtained were fully characterized using indirect ELISA and Western blot analysis. The ELISA results showed that the MAbs' titers were in the range of 1:6.400 x 10(3) - 1:1.280 x 10(4) in culture fluids, and 1:1.024 x 10(6) - 1:8.192 x 106 in ascitic fluids. The isotypes of the three MAbs were tested to be IgG1(kappa) and all the MAbs recognized the same antigenic epitope. Western blot analyses demonstrated that all the MAbs were directed against MARV-NP with the affinity constants (Kaff) of about 1.100 x 10(9) M(-1), 1.235 x 10(9) M(-1), and 1.408 x 10(9) M(-1) for the MAbs 1H4, 2G1, and 3B5, respectively.