The series of molecular signals initiated by the binding of dsRNA from another organism to the cytoplasmic pattern recognition receptor (PRR) MDA-5 (also known as IFIH1). MDA-5 detects RNA synthesized during viral replication or shed by non-viral pathogens, and triggers a signaling pathway to protect the host against infection, for example by inducing the expression of cytokines.
MDA-5 signalling pathway