A MAJOR ANTIGENIC DOMAIN OF HANTAVIRUSES IS LOCATED ON THE AMINOPROXIMAL SITE OF THE VIRAL NUCLEOCAPSID PROTEIN

Hantavirus nucleocapsid protein has recently been shown to be an immun odominant antigen in hemorrhagic with renal syndrome (HFRS) inducing a n early and long-lasting immune response. Recombinant proteins represe nting various regions of the nucleocapsid proteins as well as segments of the G1 and the G2 glycoproteins of hantavirus strains CG18-20 (Puu mala serotype) and Hantaan 76-118 have been expressed in E. coli. The antigenicity of these proteins was tested in enzyme immunoassays and i mmunoblots. These studies revealed that human IgG immune response is p rimarily directed against epitopes located within the amino acid resid ues 1 to 119 of the amino terminus of viral nucleocapsid proteins. Thi s fragment was recognized by all HFRS patient sera tested (n = 128), T he corresponding enzyme immunoassays proved to be more sensitive than the indirect immunofluorescence assays. Furthermore, the majority of b ank vole monoclonal antibodies raised against Puumala virus reacted sp ecifically with this site. A recombinant G1 protein (aa 59 to 401) der ived from the CG 18-20 strain was recognized by 19 out of 20 sera from HFRS patients.