These complex signalling recruit adaptors, including TIR-domain-containing adaptor protein including IFN-β (TRIF), mitochondrial antiviral-signalling protein (MAVS) [64] and stimulator of interferon genes protein (STING) [65] to trigger downstream cascades molecules, involving adaptor molecule MyD88 and lead to the activation of the transcription factor nuclear factor-κB (NF-κB) and interferon regulatory factor 3 (IRF3) and the production of type I Interferons (IFN-α /β) and a series of pro-inflammatory cytokines [66].