(Polyinosinic-polycytidylic acid potassium salt) TLR3 recognizes double-stranded RNA and is a major effector of the immune response against viral pathogens. Polyinosinic–polycytidylic acid (Poly(I) • Poly(C)) is a double-stranded homopolymer used as a model RNA to study cell signaling at the level of TLR3. Poly(IC) is a TRIF-dependent toll-like receptor-3 (TLR3) ligand.
Transfection of Poly (I:C) into NIT-1 cells has been used as a model of intracellular dsRNA-induced β cell apoptosis. Eighteen hours post transfection, 45% of the cells were apoptotic with an increase in NF-kB, p50/p65 nuclear translocation, and cleavage of caspases 3 and 8, as well as transcriptional induction of caspase 12, Fas, IL-15, and the TNF receptor-associated ligand (TRAIL). It has been suggested th at Poly(I:C) is one of the most appropriate generators of stable mature dendritic cells (DC). These mature DC might generate in vivo effective immune responses after injection due to their ability to secrete bioactive IL-12 after CD40 ligation. Poly (I:C) was used as a potent adjuvant to enhance the specific anti-tumor immune responses against a peptide-based vaccine.
