Detection of dengue 4 virus core protein in the nucleus. II. Antibody against dengue 4 core protein produced by a recombinant baculovirus reacts with the antigen in the nucleus.

The dengue 4 virus (DEN-4) core gene and part of the PreM genes were inserted into the baculovirus polyhedrin gene region. The recombinant baculovirus directed the synthesis of the DEN-4 core protein fused to a part of the polyhedrin protein (Mr 25K), as determined by Western blot analysis using DEN-4 core monoclonal antibody. A mouse polyclonal antibody prepared against the DEN-4 core fusion protein showed antigenic reactivity with the authentic DEN-4 core protein (Mr 15.5K) present in the nucleus as well as in the cytoplasm of DEN-4-infected Vero cells as demonstrated by the peroxidase-antiperoxidase staining method. This antibody did not react with cells infected with DEN-1, -2, -3 or Japanese encephalitis virus, or mock-infected cells.