Baculovirus expression of the nucleocapsid protein of a Puumala serotype Hantavirus.

Recombinant baculoviruses were generated harboring the entire coding region of the S segment cDNA of Hantavirus strain CG 18-20 that belongs to the Puumala serotype. The recombinant nucleocapsid protein was expressed in Sf9 cells and shown to be antigenically identical with the authentic viral nucleocapsid protein by means of immunoblot analysis. Acute-phase and convalescent sera from European HFRS patients recognized the recombinant nucleocapsid protein in Western blots and the recombinant Baculovirus in indirect immunofluorescence assays. Insect cells infected with the recombinant Baculoviruses proved to be a suitable noninfectious substitute for Hantavirus-infected Vero E6 cells as an antigen source for immunodiagnostic assays allowing the detection of antibodies in HFRS patients.