MW: High molecular weight (>1.5kb).

Toll-like receptor (TLR) 3 is an endosomal TLR that mediates immune responses against viral infections upon activation by its ligand double-stranded RNA, a replication intermediate of most viruses. TLR3 is expressed widely in the body and activates both the innate and adaptive immune systems. Toll-like receptor 3 (TLR3), melanoma differentiation-associated gene 5 (MDA5), and retinoic acid-inducible gene-I (RIG-I), all sensors of double-stranded RNA (dsRNA) are potent inducers of antiviral activity. dsRNA sensor activation -e.g. by poly (I:C)- induces pro-inflammatory TNF-α and antiviral IFN-β, but can also enhance the expression of pro-apoptotic proteins. Recently, poly (I:C)-induced cell death recently gained considerable attention as a tool to study the 'Ripoptosome' or 'Necrosome' complex, a novel intracellular signaling complex, thought to induce regulated necrosis, also called 'Necroptosis'.