Innate Immunity activated via siRNA

Abstract: RNA interference has role of gene silencing process that triggered by double-stranded RNAs. Common to all cell types، is the production of 21-24 nucleotide small interfering RNA (siRNA)، which guide the RNA-induced silencing complex (RISC) to identify and cleave target mRNA sequences. siRNA duplex are potent activators of innate immune system that induce high levels of cytokines and interferon. Toll-like receptors trigger the first line of innate immune response that is mediated by transcriptional induction of a large number of cellular genes. siRNA interact with cytoplasmic RNA sensors such: Retinoic - acid Inducible Gene -I (RIG-I)، RNA-Activated protein kinase R (PKR)، Interferon Regulatory Factor (IRF) and 2''-5'' oligo adenylate synthetase (2''-5''OAS)، Nuclear Factor kappa B cell (NF-κB). siRNA modification are on the sugar، phosphate linkage، base، overhangs and termini nucleotides leading to increase half-life siRNA. This review article describes gene silencing and innate immune caused by siRNA.