The ISG15 Knockout A-549 Polyclonal Cells product consists of a CRISPR/Cas9-edited polyclonal knockout cell population derived from the A-549 human lung carcinoma epithelial cell line, engineered to disrupt the ISG15 gene. This heterogeneous population offers a versatile loss-of-function model for studying ISG15-dependent processes without the functional biases of clonal selection.
The parental A-549 cell line was originally isolated from the lung adenocarcinoma tissue of a 58-year-old Caucasian male and serves as a well-characterized model for non-small cell lung cancer research. A-549 cells exhibit epithelial morphology and are commonly employed to investigate tumor cell signaling, proliferation, metastasis, and drug responses, making them an appropriate host for ISG15 knockout studies in a lung cancer context.
ISG15 encodes an interferon-stimulated ubiquitin-like protein that is conjugated to lysine residues on target proteins through the ISGylation pathway. Interferon-alpha, interferon-beta, and interferon-gamma activate receptors IFNAR1/IFNAR2, leading to JAK1/TYK2-mediated phosphorylation of STAT1 and STAT2, which together with IRF9 form the ISGF3 complex that transcriptionally upregulates ISG15 expression. Additional upstream regulators IRF3 and NF-??B contribute to ISG15 induction. ISG15 exerts its effects by modifying downstream targets including viral proteins, JAK1, STAT1, p53, and EF-1??, thereby modulating antiviral innate immunity, cell proliferation, and apoptosis. The conjugation machinery involves the E2-conjugating enzyme UBE2L6/UbcH8 and E3 ligases HERC5 and TRIM25, while deISGylation is catalyzed by USP18, ensuring dynamic regulation of the pathway.
In the A-549 cell background, disruption of ISG15 abrogates protein expression and ISGylation activity, impairing interferon-stimulated antiviral and immunomodulatory defenses. This model is particularly relevant for dissecting the dual roles of ISG15 in lung adenocarcinoma, influencing both tumor-intrinsic proliferation and immune interactions, including NK cell activation. The cancer-mutated A-549 environment enables precise interrogation of ISG15 signaling and pathway crosstalk, facilitating the study of potential therapeutic targets.
Key research applications include investigating ISG15-mediated antiviral innate immunity and ISGylation-dependent protein modification, utilizing assays such as interferon stimulation and viral infectivity studies. The model supports screening for ISG15-dependent signaling mechanisms via RNA-seq, western blotting, co-immunoprecipitation, and cytokine release assays. Researchers can evaluate ISG15’s role in cancer biology and test interactions with UBE2L6/UbcH8, HERC5, TRIM25, or USP18. This polyclonal knockout cell population provides a robust platform for mechanistic studies and high-content functional genomics. For further inquiries, please contact Ascent Research.
