Modes of action of interferon and analogues of 2-5A, a mediator of interferon action

In the last few years, several different interferons have been described, cloned, sequenced, expressed in heterologous systems and purified to homogeneity (Weissmann et al., 1982; Kingsman & Kingsman, 1983). In particular for human interferons there exists at least thirteen subtypes of IFN-α, one IFN-β and one IFN-γ. All these molecular species and some of their recombinant hybrids show a number of common biological properties but also distinctive antiviral (Weck et al., 1981; Kingsman & Kingsman, 1983) and other activities (Rehberg et al., 1982; Pestka et al., 1983b). Recombinant DNA technology has substantially contributed to the study of the mechanism of action of interferon and will probably continue to do so in the future by allowing a detailed analysis of the regulation and site-directed mutagenesis of IFN-induced proteins.