Interferon regulatory factors: the next generation

Interferons are a large family of multifunctional secreted proteins involve d in antiviral defense, cell growth regulation and immune activation. Viral infection induces transcription of multiple IFN genes, a response that is in part mediated by the interferon regulatory factors (IRFs). The initially characterized members IRF-1 and IRF-2 are now part of a growing family of transcriptional regulators that has expanded to nine members. The functions of the IRFs have also expanded to include distinct roles in biological pro cesses such as pathogen response, cytokine signaling, cell growth regulatio n and hematopoietic development. The aim of this review is to provide an up date on the novel discoveries in the area of IRF transcription factors and the important roles of the new generation of IRFs - particularly IRF-3, IRF 4 and IRF-7. (C) 1999 Elsevier Science B.V. All rights reserved.