Expression of the S-coded genes of lymphocytic choriomeningitis arenavirus using a baculovirus vector.

A DNA copy of the lymphocytic choriomeningitis virus (LCMV, WE strain)S RNA species has been inserted in both orientations into plasmids containing a 7.1 kb DNA sequence of the baculovirus Autographa californica nuclear polyhedrosis virus (AcNPV). The inserts were placed behind the polyhedrin gene promoter of AcNPV and in the place of the nucleotide sequences including and flanking the polyhedrin gene translation initiation codon. The derived plasmids were used to obtain recombinant AcNPV viruses after transfection of Spodoptera frugiperda cells in the presence of infectious AcNPV DNA and the selection of polyhedrin-negative viruses. The expression of the two LCMV S-coded genes, the nucleoprotein and glycoprotein precursor, in S. frugiperda cells by the recombinant baculoviruses is described. Based on the results obtained with three different expression vectors, the site of insertion of the foreign genes in the 5' non-coding region of the polyhedrin gene appears to be an important determinant of the level of expression obtained.