Toll-like receptor signaling and IRF transcription factors.

Interferon regulatory factors (IRFs) were originally discovered in the context of type I interferon (IFN-alpha/beta) gene induction, and subsequent studies on these transcription factors have revealed their remarkable functional diversity in regulating immune systems. Indeed, the critical involvement of IRF members in innate and adaptive immune responses has recently gained much attention, particularly with the recent discovery of Toll-like receptors (TLRs) and analyses of their critical functions in linking the innate and adaptive immune responses.