The IFIH1 Knockout NCI-H1975 Polyclonal Cells product is a CRISPR/Cas9-edited polyclonal knockout cell population with targeted disruption of the IFIH1 gene. This pool provides a genetically heterogeneous loss-of-function model that eliminates MDA5 expression without clonal selection, supporting studies requiring stable ablation of MDA5-dependent signaling while preserving population-level diversity.
The host NCI-H1975 cell line is a human lung adenocarcinoma model characterized by activating mutations in EGFR and PIK3CA, widely used for non-small cell lung cancer research including oncogenic signaling, drug resistance, and tumor-immune interactions, and is suitable for standard culture techniques.
IFIH1 encodes melanoma differentiation-associated protein 5 (MDA5), a cytoplasmic pattern recognition receptor that detects long double-stranded RNA. Upon ligand binding, MDA5 interacts with the mitochondrial antiviral-signaling protein (MAVS) and associates with DDX58 (RIG-I) and DHX58 (LGP2). This interaction recruits the ubiquitin ligase TRIM25 and propagates signaling through the kinases TBK1 and IKK??, which phosphorylate the transcription factors interferon regulatory factor 3 (IRF3) and IRF7. Activated IRF3/IRF7 translocate to the nucleus and drive the expression of type I interferons (IFN-??/??) and interferon-stimulated genes (ISGs) such as ISG15, thereby establishing an antiviral state. Additionally, IFIH1 expression is positively regulated by type I interferons and NF-??B, forming a feed-forward loop that amplifies innate immune responses.
In the NCI-H1975 lung adenocarcinoma background, IFIH1 knockout enables dissection of cytosolic RNA sensing in cancer-intrinsic immunity. With EGFR and PIK3CA mutations prevalent in NSCLC, this model aids in studying how tumors may subvert the MDA5-MAVS-TBK1 axis to evade interferon surveillance and promote immune escape, and to explore oncogenic signaling impacts on innate immune pathways. It also provides a platform for investigating synthetic lethal interactions and the contribution of MDA5 to anti-tumor immunity.
This knockout pool is applicable to antiviral immunity studies, viral infection models, autoimmune disease research (e.g., Aicardi-Gouti??res and Singleton-Merten syndromes), and cancer immunology. Assays include western blotting for IFIH1, MAVS, phospho-TBK1; RT-qPCR for IFN-?? and ISG15; immunofluorescence for IRF3 translocation; ISRE reporter assays; viral replication assays; and RNA-seq for transcriptome profiling. For further details, contact Ascent Research.
