FIG 7.

Model of nsP1 defective genome proviral activity (above) and interactions with antiviral anti-E2 antibody (below). nsP1 DVG expression results in increased production of SINV nsP1 protein and improved SINV RNA capping efficiency. The nsP1 DVG is packaged into defective interfering particles (DIPs) that can spread from cell to cell and replicate during coinfection with wild-type virus. Anti-E2 antibody suppresses viral RNA transcription and particularly affects SINV sgRNA and nsP1 DVG production. Anti-E2 antibody also inhibits viral and DIP budding by direct binding of surface E2. Inhibition of spread of the nsP1 DVG by inhibition of budding or neutralization contributes to overall decreased viral replication by decreasing production of nsP1 protein and decreasing SINV RNA capping efficiency during late infection.