Interferon after 30 years

IFN is a product of a growing family of IFN-genes in the vertebrate cell. It is a polypeptide which fits the definition both of lymphokines and/or "local" hormones, and, cannot be anymore considered an "autonomous antiviral factor", as postulated originally. Rather, IFN increasingly seems to play in the organism the role of a "master-lymphokine" that mediates, potentiates or regulates the effects of various lymphokines in differentiation, growth and antigen expression of cells. The antiviral, antiproliferative, cell- and antigen-activating activities of IFN formed the basis for expectations that IFN will be utilized in therapy. These expectations were only partially fulfilled. In some diseases, however, the results of clinical tests are convincing. In such tests, we learned that the successful application of IFN in disease requires other strategies than with cytostatics etc. IFN may be deleterious for the organism when present for a long time in circulation and/or applied in high doses. This follows both from observed side effects of IFN and from the mitigating effect of anti-IFN sera in some diseases.