[Signal transduction of innate immunity to virus infection]

The innate immune system is essential for the initial detection of invading viruses and subsequent activation of adaptive immunity. Three types pattern recognition receptors (PRRs) in innate immune cells play a pivotal role in the first line of host defense system. PRRs include Toll-like receptors (TLRs), RIG-I-like receptors(RLRs) and nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs). PRRs recognize pathogen-associated molecular patterns(PAMPs) or danger-associated molecular patterns (DAMPs) to initiate and regulate innate and adaptive immune responses. Three types PRRs have their own features in ligand recognition and cellular location. Activated PRRs deliver signals to adaptor molecules (MyD88, TRIF, IRAK, IPS-1), which act as important messengers to activate downstream kinases (IKK complex, MAPKs, TBK1, RIP-1) and transcription factors (NF-kappaB, AP-1, IRF3), which produce effected molecules including cytokines, chemokines, inflammatory enzymes, and type I interferons. This review focuses on discussing PRRs signaling pathways and achievements in this field in order to provide beneficial strategies for human life and immune diseases prevention.