FIG. 2.

PV replication and IFN response in cultured kidney cells. (A) Time course of PV titers in cultured kidney cells. Primary cultured kidney cells from PVR-tg mice and PVR-tg/Ifnar knockout (KO) mice were infected with PV at an MOI of 0.001. At each time point, the cells were disrupted by three cycles of freezing and thawing, and virus titers were determined by plaque assay. The PV propagation profiles in the two types of cell were indistinguishable. (B to D) Morphology of uninfected primary cultured kidney cells. At least three different kinds of cells were present in the uninfected culture. (E and F) Kidney cells from PVR-tg mice (E) and from PVR-tg/Ifnar knockout mice (F) were infected with PV at an MOI of 1.0. CPE was observed at 24 h p.i. (G and H) IFN response in cultured kidney cells from PVR-tg mice. The cells were infected with PV at an MOI of 10. Total RNA of the cells was isolated at the indicated times p.i., and the IFN-α/β (G) and OAS1a (H) mRNA levels were determined by quantitative real-time PCR analysis. The asterisks indicate a significant difference (P < 0.05; Student's t test) in comparison with the uninfected (noninf.) samples. The error bars indicate SEM. Note that the vertical scales in panels G and H are different from those in Fig. 1G to J.