[Simple method of determining the antiproliferative activity of human interferons]

A simple method for quantitative estimation of the antiproliferative activity of human interferon is described. The method is based on direct visual estimation (with the use of an inverted microscope) of various doses of interferon with respect to proliferation and colony formation of human transplantable tumor HeLa cells grown in Nells of plastic plates for microcultures. Single HeLa cells (target cells) are plated out on a monolayer of human embryo fibroblasts (HEF), which morphologically differ from the target cells (HeLa) and play the role of feeders. After that the cells are incubated at 37 degrees C in the atmosphere of 5 per cent of CO2 and humidity of 98 per cent for 4-5 days. With the use of this method for determining the anticellular activity of interferon it was shown that human gamma-interferon had a 30 times more pronounced antiproliferative activity than natural alpha- and beta-interferons and alpha-F and alpha-F/D plasmid interferons. The method provides also investigation of other aspects of the antiproliferative activity of interferon: it was shown that the physicochemical factors or antiinterferon sera inactivating the antiviral properties of the interferons were also the cause of simultaneous inhibition of their antiproliferative activity.