IFIH1/MDA5 Mouse mAb

IFIH1, also known as melanoma differentiation-associated gene 5 (MDA5), is a critical viral nucleic acid sensor in the cytoplasm that acts as a "sentinel" in initiating the antiviral innate immune response. Its primary function is to recognize long double-stranded RNA (>1 kb) or mRNA lacking 2'-O-methylation at the 5' end that has invaded the cell. Upon binding to these virus-characteristic nucleic acids, IFIH1 forms polymers through homotypic interactions and associates with the mitochondrial adaptor protein MAVS, thereby activating downstream signaling pathways and ultimately inducing the production of type I interferons (such as IFN-α and IFN-β) and pro-inflammatory cytokines to eliminate the virus. Functionally, IFIH1 belongs to the RIG-I-like receptor family alongside RIG-I, but the two exhibit a division of labor in terms of the viral spectra they recognize—for example, IFIH1 is the key receptor responsible for detecting picornaviruses (such as encephalomyocarditis virus), coronaviruses (including SARS-CoV-2), and unspliced RNAs transcribed from HIV-1 proviruses. However, gain-of-function mutations in the IFIH1 gene can lead to aberrant activation of the type I interferon signaling pathway, thereby giving rise to a range of autoinflammatory and autoimmune diseases, such as Aicardi-Goutières syndrome type 7 (characterized by intracranial calcification, leukoencephalopathy, and chilblain-like rashes), Singleton-Merten syndrome, and type 1 diabetes mellitus.