IFITM1 Knockout HAP1 Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal knockout cell population targeting the IFITM1 gene in the near-haploid HAP1 human cell line. This product provides a genetically defined loss-of-function model for investigating interferon-inducible restriction of viral entry, cell adhesion modulation, and interferon signaling pathways. The polyclonal format consists of a heterogeneous pool of cells carrying diverse IFITM1-disrupting alleles, generated by transient Cas9/sgRNA delivery, ensuring robust and versatile knockout populations for downstream assays without clonal selection artifacts. Researchers can employ these cells to dissect IFITM1-dependent antiviral mechanisms, identify host factors cooperating with IFITM1, and perform comparative phenotypic screens in a controlled genetic background.
The HAP1 host cell line, originally derived from a chronic myeloid leukemia patient, exhibits a near-haploid karyotype and fibroblast-like morphology. This near-haploidy simplifies genetic manipulation, as disruption of a single allele typically results in complete functional knockout, making HAP1 an exceptional model for genome-scale screens and functional genomics studies. The leukemia-derived origin endows HAP1 cells with cancer-relevant signaling networks, and their adherent, epithelial-like growth characteristics facilitate a broad range of cell-based assays, including high-content imaging, flow cytometry, and viral infection studies. The combination of haploid genetics and a well-characterized background renders HAP1 an ideal platform for dissecting gene function in antiviral immunity and oncogenic processes.
IFITM1 is an interferon-induced transmembrane protein that localizes to the plasma membrane and endosomal compartments, where it restricts entry of enveloped viruses by inhibiting viral envelope fusion with host membranes. Mechanistically, IFITM1 blocks fusion at the hemifusion or pore formation stages, thereby preventing cytosolic delivery of viral genomes. Transcription of IFITM1 is robustly activated by type I and type II interferons through the JAK-STAT signaling axis. Upon interferon-alpha or interferon-gamma ligation to the IFNAR receptor, the kinases JAK1 and TYK2 phosphorylate STAT1 and STAT2, which together with IRF9 form the ISGF3 complex. This complex binds interferon-stimulated response elements (ISRE) in the IFITM1 promoter, driving its expression. IFITM1 also physically interacts with cellular partners CD81 and caveolin-1, and with IFITM3 to orchestrate membrane architecture, while also binding viral glycoproteins to block fusion. Downstream consequences of IFITM1 activity include direct restriction of viral entry, modulation of cell adhesion molecules, and regulation of membrane trafficking events critical for both viral pathogenesis and tumor cell invasion.
Disruption of IFITM1 in HAP1 cells creates a powerful model to delineate the relative contribution of this restriction factor within the broader interferon-induced antiviral state. The near-haploid nature of HAP1 ensures that knockout populations exhibit unambiguous loss-of-function phenotypes, facilitating the study of IFITM1??s role in blocking entry of viruses such as influenza A virus, flaviviruses, and filoviruses. Moreover, the leukemia-derived background enables exploration of IFITM1??s involvement in cancer cell adhesion, immune evasion, and metastatic behavior, as IFITM1 has been implicated in regulating cell adhesion molecules and influence on tumor progression. Combining IFITM1 knockout with HAP1’s genetic tractability permits cost-effective, high-throughput screening for viral host dependencies or synthetic lethal partners in cancer, while eliminating concerns about gene redundancy that might complicate diploid systems.
These polyclonal knockout cells are designed for diverse research applications, including antiviral drug discovery, detailed viral entry mechanism studies, host factor genetic screening, cancer cell invasion and metastasis assays, and immune evasion research. Representative experimental modalities compatible with this product include Western blotting and RT-qPCR for confirming IFITM1 loss and interferon pathway activation, viral infection assays with luciferase- or fluorescence-tagged viruses, flow cytometry for surface marker profiling and infection quantitation, immunofluorescence microscopy for subcellular localization studies, and cell adhesion assays to assess migratory phenotypes. The IFITM1 Knockout HAP1 Polyclonal Cells thus provide a rigorous and versatile genetic tool for advancing understanding of innate antiviral immunity and cancer biology. For additional information, technical support, or custom projects, please contact Ascent Research.
