FIG.4.

Differences in virus-induced polarization and actin tails between HeLa cells infected with MVA, its parental Ankara strain, and the other VV strains, WR and NYCBH. HeLa cells were infected with the MVA, Ankara, WR, and NYCBH VV strains at 0.05 PFU/cell, and at 48 hpi cells were fixed and processed for confocal microscopy. Cytoplasmic viral p14 protein and virions were detected with an antibody to p14 protein and a secondary antibody conjugated with FITC; cellular actin was detected with phalloidin-conjugated with Far Red. In cells infected with the Ankara, WR, and NYCBH strains there is a multipolar or stellated morphology and actin tails are clearly seen in these Z-projections. In mock-infected cells the F-actin is present in fibers. However, cells infected with MVA showed a bipolar morphology, actin tails were not induced, the cells accumulated cytoplasmic p14 viral protein, and very few virions were observed. Bar, 1 μm.