FIG. 1.

Schematic diagram of a system for generating NS gene-deficient VLPs. 293T cells were transfected with plasmids expressing all viral structural proteins and seven RNA polymerase I plasmids for vRNA synthesis, omitting pPolI-WSN-NS. Forty-eight hours after transfection, supernatants derived from transfected cells were used to infect MDCK cells. Progeny virus was not produced from the VLP-infected cells.