The IFI44 Knockout HEK293T Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout population with targeted disruption of the IFI44 gene in HEK293T cells. This loss-of-function model avoids clonal artifacts and provides a robust system to study IFI44’s role in antiviral innate immunity and interferon signaling.
HEK293T cells, human embryonic kidney epithelial cells transformed with adenovirus 5 DNA and expressing SV40 large T-antigen, are renowned for high transfectability, rapid growth, and utility in recombinant protein expression and viral production. Their intact interferon (IFN) signaling and permissiveness to various viruses make them an ideal platform for dissecting host antiviral factors.
IFI44 encodes a microtubule-associated protein induced by type I interferons (IFN-??/??) via the IFNAR-JAK-STAT pathway: IFN binding to IFNAR1/2 activates JAK1 and TYK2, which phosphorylate STAT1/2; these recruit IRF9 to form ISGF3 and drive IFI44 transcription. IFI44 restricts replication of diverse viruses, including hepatitis C virus and HIV. It also exerts negative feedback on IFN signaling by binding FKBP5, an immunophilin that inhibits IRF3 phosphorylation, thereby attenuating IFN induction. Additional partners include GBP1 and homodimerization, situating IFI44 at a key node between antiviral effector function and regulatory control of innate immunity.
In HEK293T cells, IFI44 knockout allows precise dissection of its dual role in viral restriction and IFN pathway modulation. The cells are permissive to many viruses and exhibit robust ISG responses, enabling side-by-side comparison with wild-type controls. This model is especially relevant for studying negative feedback in IFN signaling, which is dysregulated in autoimmune diseases like systemic lupus erythematosus. The polyclonal nature preserves genetic heterogeneity while achieving effective IFI44 disruption.
Research applications include functional analysis of IFN-dependent antiviral responses, investigation of viral replication restriction, and dissection of negative feedback in JAK-STAT signaling. The model is also useful for autoimmune disease research (e.g., type I interferonopathies) and screening of IFN pathway modulators. Typical assays: western blot for IFI44, RT-qPCR for ISGs, viral replication assays, co-IP with FKBP5, ISRE luciferase reporter, immunofluorescence for microtubule association, and flow cytometry for viral proteins. Contact Ascent Research for further technical information.
