FIG 6.
DIP interference on rCDVRI infection in vitro. (A) Natural copyback DIs (nDIs) 07, 04, 10, and 11 (Table 2) and synthetic deletion DIP sDIRILedTomTr were tested for their ability to interfere with rCDVRI replication in vitro. The amount of inhibition of rCDVRI infection in Vero-cCD150 cells is visualized by cytopathic effect (CPE) (cell monolayers stained with crystal violet). N, neat, undiluted DIP stock. (B) Dose-response curve for copyback sequence nDIRI04cb. To obtain a dose at which a DIP completely eliminates CDV infection, Vero-cCD150 cells were treated with specific ratios of virus and DIPs (green line). Control infections were performed using UV-inactivated DIPs (red line) to demonstrate that interfering effects were DI genome replication specific. rCDVRI titers were measured by determining the TCID50 per milliliter at 72 h postinfection. Error bars represent standard deviations (n = 3).