[Effect of interferon on the cAMP system in cells].

The increase in cAMP concentration in CaOv cells affected by alpha-interferon has been found to have a two wave character with the maximums at 4 and 24 h after the effect. The waves are due to the increase in adenylate cyclase activity and to the decrease in the activity of cAMP phosphodiesterase. The described changes were characteristic of the native and partially purified interferon and depended on the concentration of interferon used (optimal effect at 1200 IU/ml-1).

[Effect of inhibitors that destroy cytoskeleton structures on the antiviral and antiproliferative activity of interferons].

The effect of a number of drugs (vincristine, vinblastine, cytochalasin B, colcemid, colchamine) destroying cytoskeleton structures (microtubules and microfilaments) in combination with homologous interferon was studied in L920 and CaOv cells. The above substances were shown to inhibit the antiviral and enhance (from additivity to synergism) the antiproliferative effect of interferons under study.

[Effect of human interferons on cAMP phosphodiesterase activity in a culture of human ovarian carcinoma cells (CaOv)].

Crude and purified human interferons of alpha type exerted 2 step inhibition of cAMP phosphodiesterase activity in CaOv cells: in 4 and 24 hours after cells treatment with interferon. The maximal inhibition was obtained in response to interferon doses 1200-2000 IU/ml. In contrast to natural interferons the human alpha 2 recombinant interferon (20-25000 IU/ml) did not inhibit the cAMP phosphodiesterase activity in CaOv cells.

[Antiviral and antiproliferative activity of human fibroblast interferon fractions].

The affinity chromatography of Human crude beta-interferon preparations on Blue Dextran Sepharose columns resulted in isolation of several fractions with different ratio of antiviral to antiproliferative activities. The results of investigation of two of these fractions are described in this report. The first of them was eluted by 1N NaCl in 0.