Origin and Possible Mode of Action of a Tissue Antagonist of Interferon

WE have presented data¹ supporting the hypothesis proposed by Taylor² and by Friedman and Sonnabend³ that interferon acts through a protein which confers the antiviral state on the cell. We postulated two separate regulatory mechanisms: one governing interferon synthesis and the other the production and action of the antiviral protein in the cell⁴. Our studies on the regulation of the antiviral state led us to the demonstration of a substance in human amniotic and chorionic membranes which, when added to the cell 4–18 h after interferon, decreased the antiviral state⁵. The extraction and purification of this tissue antagonist of interferon (TAI) have been previously described. TAI was resistant to proteases (trypsin, pepsin) and to nucleases (RNAase, DNAase). It was also resistant to heating at 56° C or 75° C for 1 h and was only inactivated at 95° C. Although the biologically active component was not chemically defined, its properties were reminiscent of mucopolysaccharides. It is unknown at present whether the TAI represents a substance or a group of substances.