The ISG15 Knockout Ca Ski Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population featuring targeted disruption of the ISG15 gene in the human Ca Ski cervical carcinoma cell line. This loss-of-function model eliminates ISG15 protein expression and its downstream activities, providing a physiologically relevant system for studying ISG15-dependent processes without clonal selection artifacts. The polyclonal nature retains the genetic heterogeneity of the parental cells, suitable for advanced biomedical research on antiviral immunity, protein ISGylation, and immune signaling.
The Ca Ski host cell line is derived from a cervical squamous cell carcinoma metastasis and contains integrated HPV-16 genomes. It constitutively expresses the viral oncoproteins E6 and E7, which disrupt tumor suppressors p53 and pRb to promote cellular transformation. Ca Ski cells serve as a well-established model for studying HPV-driven cervical carcinogenesis and the interaction between viral oncogenes and host innate immune pathways, including the interferon response.
ISG15 encodes a ubiquitin-like protein critical for antiviral innate immunity. Upon IFN-??/?? stimulation, ISG15 is transcriptionally induced via the JAK-STAT pathway through STAT1/STAT2/IRF9 complexes. It functions intracellularly through ISGylation, a process catalyzed by UBE1L, UBCH8, and E3 ligases HERC5 or TRIM25, and is reversed by USP18. ISG15 modifies key immune mediators such as JAK1, STAT1, IRF3, PKR, and RIG-I, enhancing antiviral signaling. Extracellularly, it acts as a cytokine and interacts with LFA-1 integrin to regulate immune cell function, linking viral nucleic acid sensing by IRF3/IRF7 to NF-??B activation.
In Ca Ski cells, ISG15 knockout is anticipated to disrupt the antiviral and immune signaling network, potentially altering interferon-mediated control of HPV oncogene expression. Loss of ISG15 and ISGylation may attenuate the cellular response to IFN, impacting E6/E7 regulation and downstream oncogenic pathways. This model enables dissection of ISG15’s role in cervical cancer progression, including its effects on cell migration and invasion, and its contribution to immune evasion mechanisms exploited by HPV.
This polyclonal knockout cell model is suited for a range of applications, including antiviral activity assays, RNA-seq analysis of ISG15-dependent transcriptomes, and Western blotting to assess ISGylation. RT-qPCR quantifies interferon-stimulated gene expression, while flow cytometry examines LFA-1 surface levels. Researchers can investigate HPV E6/E7 expression changes and perform migration and invasion assays to evaluate tumor cell behavior. The cells also support therapeutic screening of compounds targeting interferon signaling or HPV oncoproteins. For further details, please contact Ascent Research.
