Role of the membrane-bound receptor system in the biological activity of interferon.

The model of the interferon receptor system initially proposed in 1973 is now supported by many independent observations and can be described with somewhat more precision. The cell membrane-bound receptor system consists of a nonspecific binding site made up of gangliosides (such as GM2). The activator site is probably formed by glycoproteins. It is likely that interferon has to interact with both sites at the surface of the cell membrane. The activator site carries probably the interferon species specific properties of the receptor, while all the other metabolic steps necessary for the development of antiviral activity are not species specific. The cooperation (resulting most likely in small aggregates) will change the conformational state of the membrane in a way compatible with the action of interferon. We postulate that many other cellular effects of interferon, such as priming, modification of antigenic properties, changes in membrane permeability, increase or decrease in sensitivity to toxins, repression of cellular DNA synthesis could be secondary effects related to cell membrane modulation. Experiments are now in progress to prove or disprove these postulates.