The IRF3 Knockout NCI-H1975 Polyclonal Cells product provides a polyclonal population of NCI-H1975 human lung adenocarcinoma cells in which the IRF3 gene has been functionally disrupted via CRISPR/Cas9-mediated gene editing. This knockout pool, rather than a clonal isolate, preserves genetic diversity and serves as a robust loss-of-function model for investigating IRF3-dependent signaling networks in a background that closely reflects the heterogeneity of tumor cell populations. The polyclonal format is well-suited for studies requiring representative cellular responses without the bottlenecks of single-cell cloning.
NCI-H1975 is a human non-small cell lung cancer (NSCLC) cell line derived from a female patient with adenocarcinoma. It harbors activating mutations in the epidermal growth factor receptor (EGFR), specifically L858R and T790M, which are associated with oncogenic signaling and acquired resistance to first-generation EGFR tyrosine kinase inhibitors. This epithelial cell line is widely employed as a model for EGFR-driven lung adenocarcinoma, enabling dissection of tumor-intrinsic signaling and therapeutic vulnerabilities.
IRF3 (interferon regulatory factor 3) is a pivotal transcription factor in innate antiviral immunity. It is activated by TBK1 and IKK?? kinases downstream of cytosolic nucleic acid sensors, including the cGAS-STING axis and RIG-I/MAVS pathway, as well as endosomal toll-like receptors such as TLR3 and TLR4. Upon phosphorylation, IRF3 dimerizes and translocates to the nucleus, where it cooperates with co-activators CBP and p300 to drive transcription of type I interferons (IFN-??, IFN-??), interferon-stimulated genes (ISG15, ISG54), and pro-inflammatory chemokines like CXCL10 and CCL5. IRF3 also interacts with IRF7 and STAT1 to amplify innate immune signals.
In the context of lung adenocarcinoma, IRF3 exerts context-dependent tumor-modulatory functions, often promoting immune surveillance through induction of interferon responses that recruit and activate immune cells. The NCI-H1975 background, characterized by EGFR-driven proliferation and intrinsic immune evasion mechanisms, provides a relevant platform to dissect how IRF3 loss impacts tumor cell-intrinsic innate signaling, cytokine production, and sensitivity to EGFR inhibitors. This knockout model enables exploration of whether IRF3-mediated innate immune pathways contribute to therapeutic responses or resistance in EGFR-mutant NSCLC.
Researchers can employ this polyclonal knockout cell product in diverse experimental paradigms, including interrogation of innate immune signaling agonists (e.g., STING or RIG-I ligands), viral infection assays, and co-culture systems to assess immunomodulatory effects. Representative techniques include Western blotting for total and phospho-IRF3, RT-qPCR for ISG transcripts, interferon-?? reporter luciferase assays, ELISA-based measurement of IFN-?? and CXCL10, immunofluorescence to track IRF3 nuclear translocation, and flow cytometry to profile immune activation markers. Co-immunoprecipitation with TBK1 or drug sensitivity studies can further elucidate pathway crosstalk and therapeutic vulnerabilities. For additional technical details or custom requests, please contact Ascent Research.
