[Human immune interferon: production and action]

The most marked production of immune interferon by human peripheral blood leukocytes and splenocytes stimulated with phytohemagglutinin (PHA) and staphylococcal enterotoxin A (SEA) was shown to be achieved when lymphoid cells are propagated under conditions of constant sparing mixing on roller apparatus at a temperature of 37 degrees +/- 0.5 degrees C. The resulting interferon was sensitive to low pH, thermolabile, inactivated by treatment with trypsin, and not neutralised by antisera to human alpha- and beta-interferons. The antiviral properties with regard to vesicular stomatitis and Semliki Forest viruses were practically similar in PHA- and SEA-induced interferon and human alpha- and beta-interferons. The capacity to inhibit colony formation by HeLa cells was 30 times higher in gamma-interferon than the antiproliferative activity of alpha- and beta-interferons.