Relationship between the physicochemical nature of human interferon, the cell induced, and the inducing agent.

To determine the basis for differences in interferons previously noted by others, we prepared five types of human interferon, namely interferon induced in muscle skin fibroblasts using complexed polyinosinic:polycytidylic acid (IC) and Newcastle disease virus (NDV), and interferon induced in leukocytes using IC, NDV, and phytohemagglutinin. We determined the molecular weight, isoelectric point, inactivation rate at 56 degrees C and structural activity relationships for each interferon. Significant differences between these interferons were found, many of which seem related to the cell induced rather than the inducer. We believe these findings have important pharmacological implications for the use of interferon in man.