The innate immune system plays a critical role in pathogen recognition and 
initiation of protective immune response through the recognition of pathogen 
associated molecular patterns (PAMPs) by its pattern recognition receptors 
(PRRs). Nucleic acids including RNA and DNA have been recognized as very 
important PAMPs of pathogens especially for viruses. RNA are the major PAMPs of 
RNA viruses, to which most severe disease causing viruses belong thus posing a 
tougher challenge to human and animal health. Therefore, the understanding of 
the immune biology of RNA PRRs is critical for control of pathogen infections 
especially for RNA virus infections. RNA PRRs are comprised of TLR3, TLR7, TLR8, 
RIG-I, MDA5, NLRP3, NOD2, and some other minorities. This review introduces 
these RNA PRRs by describing the cellular localizations, ligand recognitions, 
activation mechanisms, cell signaling pathways, and recognition of pathogens; 
the cross-talks between various RNA PRRs are also reviewed. The deep insights of 
these RNA PRRs can be utilized to improve anti-viral immune response. © 2017 
IUBMB Life, 69(5):297-304, 2017.