[Formation of an acid-labile interferon induced in human leukocytes by the influenza virus]

Predominantly acid-labile interferon was produced by treatment with influenza virus (inducer) of a portion of leukocytes followed by their addition to the main cell pool. This interferon could be detected by treatment of the material with antiserum to the inducer virus and ultracentrifugation. This treatment completely eliminated the activity of the virus-inducer present in the material. Typing of the acid-labile interferon with the employment of antisera to alpha and gamma interferons demonstrated its belonging to the alpha type.