The IFIH1 Knockout SK-HEP-1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout population featuring disruption of the IFIH1 gene in the SK-HEP-1 cell line. This heterogeneous pool of edited cells enables loss-of-function studies without clonal selection bias, maintaining genetic background diversity while silencing target gene expression. It is suited for population-based assays in innate antiviral immunity research, providing a flexible tool for investigating RIG-I-like receptor signaling.
SK-HEP-1 is a human liver adenocarcinoma-derived cell line that exhibits endothelial characteristics, functionally modeling liver sinusoidal endothelial cells (LSECs). LSECs line the liver sinusoids and are critical for filtration, scavenging of macromolecules, and immune surveillance. This widely used line supports studies of hepatic endothelial biology, including pathogen sensing, cytokine production, and the liver??s immune-tolerant microenvironment, while retaining key endothelial markers and offering robust in vitro growth.
IFIH1 (MDA5) encodes a cytoplasmic sensor for viral double-stranded RNA, 5??-triphosphate RNA, and poly(I:C). Following ligand recognition, IFIH1 interacts with MAVS, which recruits TRAF3 and TRAF6 to activate TBK1 and IKK??. These kinases phosphorylate IRF3 and NF-??B p65, driving nuclear translocation and transcriptional induction of type I interferons (IFNB1, IFNA) and cytokines such as CXCL10 and ISG15. IFIH1 cooperates with RIG-I and LGP2, and its signaling is modulated by upstream interferon regulatory factors. This pathway is central to antiviral innate immunity.
In LSECs, IFIH1-mediated innate signaling is crucial as these cells continuously encounter blood-borne pathogen-associated molecular patterns. Knocking out IFIH1 in SK-HEP-1 removes the primary sensor for cytoplasmic viral RNA, enabling dissection of LSEC-specific interferon responses during hepatic viral infections (e.g., hepatitis viruses) and systemic diseases affecting the liver. This model helps clarify the sentinel function of LSECs in hepatic immune surveillance.
This IFIH1 knockout population supports dissection of RLR signaling via co-immunoprecipitation of IFIH1-MAVS complexes and western blot analysis of phospho-IRF3. It is directly applicable in luciferase reporter assays under the IFNB1 promoter, RT-qPCR quantification of IFNB1 and ISG15, immunofluorescence tracking of IRF3 nuclear translocation, and viral replication assays. The model facilitates drug screening for modulators of antiviral innate immunity and enables mechanistic studies of interferonopathies such as Aicardi-Gouti??res syndrome and Singleton-Merten syndrome. For further information, please contact Ascent Research.
