Chapter 34 : Introduction

Abstract:

Nearly 60 years ago, the first cytokine was described. Today, >300 cytokines, chemokines, and adhesion molecules have been identified. We have witnessed an explosion in knowledge about cytokine biology. This can be highlighted by reviewing the interferon (IFN) molecules as an example. IFN was first identified in 1957 as a potent antiviral molecule. We now know that there are four major types of IFNs (alpha, beta, gamma, and lambda). Although IFN was first identified as an antiviral protein, IFNs are now recognized as critical immunoregulatory proteins capable of altering various cellular processes, including cell growth, differentiation, gene transcription, and translation. The advent of innate immunity and Toll-like receptors revealed the intimate role of IFNs in innate immune responses. The presence of IFN-α is a critical component of the autoimmune disease systemic lupus erythematosus. Advances in biotechnology and molecular biology have generated highly specific reagents with clinical relevance. In fact, the IFNs have been approved by the Food and Drug Administration for the treatment of infections, malignancies, autoimmunity, and immunodeficiency. IFN-α treatment is efficacious for hepatitis C infection, IFN-β for multiple sclerosis, and IFN-γ for chronic granulomatous disease. The examples outlined for the IFNs can be replayed throughout the cytokine kingdom.