IFIT1 Knockout HT29 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal cell population derived from HT29 human colon adenocarcinoma cells, featuring targeted disruption of the IFIT1 gene. This knockout model provides a heterogeneous population of IFIT1-deficient cells, enabling loss-of-function studies without clonal selection biases. The polyclonal format offers a robust system to examine the consequences of IFIT1 ablation on antiviral innate immunity and interferon signaling in an intestinal epithelial background.
HT29 cells are a well-characterized human colorectal adenocarcinoma line that retains epithelial features, including mucus secretion, microvilli, and the capacity to form polarized monolayers. They serve as a standard model for investigating intestinal epithelial biology, barrier function, and colorectal cancer pathogenesis. Their differentiation potential and tumor origin make them particularly suitable for exploring the crosstalk between innate immune pathways and epithelial homeostasis or malignancy.
IFIT1 is a critical antiviral effector induced by type I interferons (IFN-??/??). Its expression is driven by JAK-STAT signaling: upon IFN binding to IFNAR1/2, JAK1 and TYK2 phosphorylate STAT1 and STAT2, which associate with IRF9 to form ISGF3, activating ISRE-containing genes. IFIT1 functions as a sensor of 5??-triphosphate RNA??a hallmark of viral genomes??leading to sequestration of viral RNA and inhibition of translation initiation through interaction with the eIF3 complex. IFIT1 operates within a network involving upstream sensors RIG-I and MDA5, transcription factors IRF3/IRF7, and co-factors IFIT2, IFIT3, and PPP2R1A, collectively suppressing viral replication.
Disruption of IFIT1 in HT29 cells abrogates a key antiviral barrier, rendering the intestinal epithelial model more susceptible to RNA viruses such as vesicular stomatitis virus and influenza. This makes the polyclonal knockout cells valuable for dissecting interferon-stimulated gene (ISG)?Cmediated restriction mechanisms in mucosal surfaces. Moreover, the model is pertinent to exploring how compromised antiviral innate immunity influences colorectal cancer immune surveillance and inflammatory bowel disease, where interferon signaling plays a dual role.
Applications include measurement of IFIT1 protein loss by western blotting after IFN stimulation, transcriptional profiling of ISGs via RT-qPCR or RNA-seq, and assessment of viral susceptibility through infection assays with VSV or influenza. Functional interactions can be probed by co-immunoprecipitation of IFIT1 with eIF3, and cellular responses visualized by immunofluorescence. Flow cytometry enables quantification of viral protein expression, and MTT assays evaluate post-infection viability. This knockout model supports drug screening for interferon response modulators and mechanistic studies of antiviral innate immunity in intestinal epithelium. For additional details, please contact Ascent Research.
