RECOMBINANT EBOLA-VIRUS NUCLEOPROTEIN AND GLYCOPROTEIN (GABON-94 STRAIN) PROVIDE NEW TOOLS FOR THE DETECTION OF HUMAN INFECTIONS

After cloning and sequencing the glycoprotein (GP) gene of one of the Gabonese strains of Ebola virus isolated during the 1994-1996 outbreak , it was shown that the circulating virus was of the Zaire subtype. Th is was confirmed in this study by cloning and sequencing the nucleopro tein (NP) gene of this strain. These two structural proteins were also expressed as recombinant proteins and used in ELISA tests. NP was exp ressed as a His-tagged fusion protein in Escherichia coli and was puri fied on resins charged with nickel ions. GP was expressed by means of recombinant baculoviruses in Spodoptera frugiperda cells. Both recombi nant proteins reacted positively in ELISAs for the detection of IgG an tibodies in convalescent human sera from Gabon and Zaire. The differen ce in the relative titres of anti-NP and -GP antibodies was variable, depending on the sera. In addition, the recombinant NP reacted with he terologous sera from Cote d'lvoire and was used successfully to detect IgM antibodies by mu-capture ELISA in sera from Gabonese patients.