The ISG15 Knockout Jurkat Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population derived from the Jurkat human T-lymphocyte cell line, engineered to disrupt the ISG15 gene. This knockout model, provided as a mixed population of edited cells, enables loss-of-function studies without clonal selection artifacts. The polyclonal format preserves cellular heterogeneity while eliminating functional ISG15 expression, making it suitable for robust and reproducible experiments. Researchers can investigate ISG15-dependent processes in a physiologically relevant T-cell context using this gene-edited product.
Jurkat cells are a widely used immortalized T-lymphocyte line established from an acute T-cell leukemia patient. They serve as a well-characterized model for T-cell receptor signaling, apoptosis, and leukemia biology. The cells exhibit key features of human T cells, including surface CD3 and CD28 expression, and respond to various stimuli such as phorbol esters and calcium ionophores. This host background provides a relevant platform for studying T-cell activation pathways and their intersection with innate immune signals, particularly in the context of viral infection and oncogenesis.
ISG15 encodes a ubiquitin-like protein that is robustly induced by type I interferons (IFN-??/??) through the JAK-STAT pathway. Upon activation of IFNAR1/IFNAR2 receptors, JAK1 and TYK2 phosphorylate STAT1 and STAT2, which together with IRF9 form the ISGF3 complex to drive ISG15 transcription. ISG15 exerts its functions via two distinct mechanisms: intracellular ISGylation, a conjugation process involving the E1 enzyme UBE1L, E2 enzyme UBCH8, and E3 ligases such as HERC5 and TRIM25, and extracellular cytokine-like signaling. ISG15 conjugates to target proteins including RIG-I, IRF3, and PKR, modulating antiviral innate immunity and NF-??B signaling. USP18 acts as a specific deISGylating enzyme, tightly regulating this modification. In the knockout cells, disruption of ISG15 abrogates ISGylation and the extracellular signaling roles of ISG15, thereby impairing antiviral feedback loops and NF-??B-mediated transcriptional responses.
In the Jurkat T-cell background, ISG15 plays a critical role at the interface between innate immunity and T-cell biology. ISG15 deficiency alters protein modification networks that control lymphocyte activation, survival, and cytokine production. Given Jurkat cells’ leukemic origin, this knockout model offers insights into how antiviral pathways intersect with oncogenic signaling. The loss of ISG15 may affect the balance of pro-survival and pro-apoptotic signals following interferon stimulation or viral challenge, making it a valuable tool for dissecting immune evasion mechanisms in T-cell malignancies. Additionally, ISG15??s function as an extracellular cytokine can influence neighboring cells, and its absence in Jurkat cells allows the study of both autocrine and paracrine effects in co-culture systems.
Researchers can employ the ISG15 Knockout Jurkat Polyclonal Cells in a wide array of functional assays. Western blotting and RT-qPCR confirm the absence of ISG15 protein and mRNA, while co-immunoprecipitation and ISGylation assays reveal the impact on protein conjugation targets. Interferon stimulation experiments (using IFN-?? or IFN-??) alongside antiviral activity assays help dissect the role of ISG15 in innate defense against viruses such as influenza or HIV. Flow cytometry enables profiling of T-cell activation markers and cytokine receptors, and reporter gene assays for NF-??B and IRF provide quantitative readouts of signaling pathway activity. These applications make the product suitable for drug screening campaigns aimed at immune modulators and for investigating the crosstalk between ISG15 and T-cell receptor signaling. For further information or custom modifications, please contact Ascent Research.
