Reduced steady-state levels of vaccinia virus-specific early mRNAs in interferon-treated chick embryo fibroblasts.

The molecular mechanism of interferon action on vaccinia virus-specific immediate early protein synthesis was studied in interferon-treated chick cells. In line with previous observations, the synthesis of total vaccinia WR virus-specific mRNA, thymidine kinase (TK) mRNA, and several other early mRNAs was detectable by short [3H]uridine pulses. Under conditions of over 90% inhibition of poxvirus-specific TK induction, accumulation of TK mRNA was strongly inhibited.

Purification of chick interferon by zinc chelate affinity chromatography and sodium dodecylsulfate-polyacrylamide gel electrophoresis.

An improved purification method for chick interferon from the allantoic fluid of embryonated chick eggs is described. Interferon prepurified by perchloric acid treatment, zinc acetate precipitation, and chromatography on SP-Sephadex C-25 was further enriched by column chromatography on zinc chelate. Analysis on sodium dodecylsulfate polyacrylamide gel electrophoresis of the interferon preparation with a specific activity of 8 X 10(5) units/mg protein shows that the major antiviral activity migrated in a broad band in the range of 20-29 kD molecular weight.

Synthesis of early vaccinia-virus-specific enzymes under conditions of immediate early gene expression.

Cycloheximide reversal experiments in chick embryo fibroblasts and mouse L-929 cells indicate that the poxvirus-induced enzymes DNA polymerase and 'alkaline' DNase are immediate early gene products of the virus. In contrast to the vaccinia-WR-coded enzyme under conditions of immediate early gene expression the cowpox-virus-induced DNA polymerase is made only in very small amounts. The studies are consistent with the notion that all poxvirus-specific early proteins may be immediate early viral gene products.

Herpes simplex virus-induced cell surface protrusions.

Cell surface alterations following herpes simplex virus infection were studied by scanning electron microscopy at different times after infection of chick embryo fibroblasts and Vero cells. Beginning at 4 h, an increasing number of cells showed numerous microvillus protrusions 0.12-0.