[Antiproliferative action of swine leukocyte interferon and of an inhibitor of interferon action]. / Antiproliferativnoe deistvie svinogo leikotsitarnogo interferona i ingibitora deistviia interferona.

The results of the study of the antiproliferative effect of swine leukocyte interferon and of an inhibitor of interferon effect in experimental mice with transplanted Krebs-2 ascitic carcinoma cells are presented. The interferon inhibitor exerted antiproliferative effect similar to that of native swine interferon. Combined use of swine interferon and interferon inhibitor did not lead to summation of the antiproliferative effect of these preparations.

[Production of inhibitors of interferon action by cell lines sensitive and insensitive to the antiviral action of interferon]. / Produktsiia ingibitorov deistviia interferona kletochnymi liniiami, chuvstvitel'nymi i nechuvstvitel'nymi k protivovirusnomu deistviiu interferona.

The capacity of a number of human and murine cell cultures to produce, upon virus induction of interferon synthesis, low molecular admixtures inhibiting interferon antiviral activity was studied. The cells resistant to interferon were found to be 8-16 times as active producers of these admixtures as sensitive cells. A possible role of the production of these admixtures in functional, i. e. not depending upon the interferon receptor gene, fluctuations of interferon inducibility and sensitivity to it is discussed.

[Inactivation of the inductor virus (Newcastle disease virus) during the isolation of porcine leukocyte interferon]. / Inaktivatsiia virusa-induktora (virus bolezni N'iukasla) v protsesse polucheniia svinogo leikotsitarnogo interferona.

The use of the routine method for inactivation of the inductor virus by acidification of interferon to pH 2.0 resulted in a significant decrease in the antiviral activity of pig leukocytic interferon, since the preparation was highly sensitive to changes in the pH values. The use of 0.1 per cent solution of formalin provided complete inactivation of the virus. The antiviral activity of interferon treated with formalin was on an average 5 times higher than that of the preparation incubated at pH 2.5-2.6. Precipitation of pig interferon with polyethylene glycol promoted both increasing of the titers of the antiviral activity of the preparation and elimination of the formalin residues from it. Interferon prepared with this procedure was not toxic in tissue cultures, had no side effects when applied to the eye mucosa and was absolutely harmless when administered to animals. It was shown that inactivation of the inductor virus with formalin was in principle possible in human leukocytic interferon.

[Concentration of heterogeneous leukocyte interferon]. / Kontsentrirovanie geterogennogo leikotsitarnogo interferona.

A comparative study of different methods for concentration of porcine leukocyte interferon active in human cells was carried out. Ultrafiltration in an apparatus TCF-10 was found to be the most effective method of concentration by which preparations of porcine interferon showing antiviral activity up to 1 X 10(6) IU/ml were obtained. The total antiviral activity of concentrated interferon was twice as high as that of the native preparation. This increase of the total initial activity is due to the removal in the process of concentration of an inhibitor of antiviral activity which was isolated and concentrated. The concentrated preparation of porcine leukocyte interferon is now undergoing trials in veterinary and medicine.