Scanning electron microscopy of L-929 cells exposed to interferon and reovirus.

L-929 cells were studied under the scanning electron microscope (SEM) in the course of reovirus infection with and without prior interferon treatment. Two major stages in the cytopathic effect (CPE) were identified on the basis of fine surface morphology as revealed by SEM. Uninfected control cells were spindle-shaped with microvilli and numerous filopodia and were firmly attached to the substratum. In stage 1 of CPE, the cells lose filopodia and develop large blebs. Stage 2 is characterized by undulating surface and pits on the nearly spherical cells which are devoid of microvilli and filopodia. At all time intervals observed post infection, interferon-treated reovirus-infected cells showed more advanced CPE than the non-interferon-treated reovirus-infected counterpart controls.