3-5-1- RIG-I like receptor signaling
The RIG-I like receptors are cytoplasmic sensors that detect viral RNA
PAMPs in a wide range of cell types. The RLRs RIG-I and melanoma
differentiation-associated gene 5 (MDA5) are ISGs that are transcribed
during SARS-CoV infection in vitro and SARS-CoV could probably be
detected by the same sensors. RLR signaling leads to the activation of
several transcription factors, such as interferon regulatory factor 3
(IRF3), IRF7, and nuclear factor-kB (NF-kB). IRF3 and IRF7 initiate
transcription of IFNs type I (IFN-α and IFN-β), which are important for
antiviral responses. NF-kB mediated transcription of proinflammatory
cytokines has been linked to the pathogenesis of ARDS (Galani et al.,
2010). While the correlation of severe SARS-CoV disease with different
transcriptional regimes is promising, the key to finding determinants of
increased SARS-CoV pathogenesis maybe understanding the way innate
immune sensing mechanisms initiate transcription at critical junctures
during infection and the types of innate immune sensing that are
protective (Totura & Baric, 2012).