CHANGES IN ALPHA-1-ANTICHYMOTRYPSIN EXPRESSION IN VACCINIA VIRUS-INFECTED HEPG2 CELLS

Human hepatoma cells (HepG2) synthesize and secrete several plasma pro teins that are inhibited in a time-and dose-dependent manner after vac cinia virus infection. However, infection of the HepG2 cells with a lo w dose of the virus (up to 1 plaque forming unit/cell) stimulated the expression of alpha-1-antichymotrypsin, which was demonstrated by mean s of electroimmunoassay and Northern blot analysis. This stimulation a ppeared to be on the level of transcription as shown in transient tran sfection experiments using various alpha-1-antichymotrypsin gene promo ter constructs. In contrast to interleukin-6, virus-induced activation of the alpha-1-antichymotrypsin gene transcription does not require t he STAT (signal transducers and activators of transcription) binding e lements present in the alpha-1-antichymotrypsin gene promoter. Further more, alpha-amanitin, which inhibits eukaryotic RNA polymerase II and III, did not affect alpha-1-antichymotrypsin stimulation by the virus, indicating involvement of the viral transcriptional apparatus in tran sient activation of alpha-1-antichymotrypsin gene expression.