Host cells comprising cDNA corresponding to the antigenome of nonsegmented negative strand RNA viruses, further encoding antigenically active proteins

An isolated eukaryotic host cell comprising (1) stably transfected expression plasmids that allow genomic expression of an exogenous RNA polymerase, a viral N protein, and a viral P protein in the host cell;

• (2) a nucleic acid sequence encoding a viral L protein;
• and (3) a cDNA molecule, said cDNA molecule comprising:
• (a) a (+) strand sequence of a non-segmented negative-strand RNA virus of the family Paramyxoviridae from which RNA transcripts bearing the authentic 3′ termini can be transcribed;
• and
• (b) an expression control sequence,
• wherein said (+) strand sequence of a non-segmented negative-strand RNA virus is operatively linked to the expression control sequence, and wherein the host cell, without a replicating vaccinia helper virus, produces an infectious RNA virus containing the (−) strand sequence of the non-segmented negative-strand RNA virus of the family Paramyxoviridae, said (−) strand sequence of the non-segmented negative-strand RNA virus obeying the rule of six.