Résumé
Several hundred original papers are published annually about interferon (IFN), and it is, thus, out of the question to cover the field extensively. This chapter attempts to review broadly major aspects of IFN research and focuses on a few molecular aspects which have been progressing significantly in recent years. Reference is frequently made to review covering particular aspects of the field in more detail. The term IFN was coined in 1957 by Isaacs and Lindenmann for cell-secreted material mediating viral interference; that is, a phenomenon by which inactivated virus virus protected animal cells from the cytopathic effect of a later virus challenge. Since IFN was discovered as an antiviral molecule, most early studies were devoted to its induction by viruses and other pathogenic agents. In vivo, IFNs probably exert their antiviral action through direct effects on virus-infected cells and through their immunomodulatory activity. Type I IFN can be induced by several types of microorganisms.