IDO1 Knockout HeLa Polyclonal Cells are a CRISPR/Cas9-edited cell population derived from the human HeLa cell line, engineered for loss-of-function of the IDO1 gene. The product comprises a polyclonal pool of edited cells, maintaining heterogeneity while achieving robust gene disruption across the population. This format avoids clonal selection biases and provides a stable model for investigating indoleamine 2,3-dioxygenase 1 (IDO1) function in a cervical adenocarcinoma context.
HeLa cells are an immortalized adherent epithelial cell line originating from HPV18-positive cervical adenocarcinoma. The viral oncoproteins E6 and E7 inactivate the tumor suppressors p53 and Rb, respectively, driving continuous proliferation and genomic instability. This well-characterized background makes HeLa cells a standard platform for studying oncogenic signaling and tumor-host interactions, particularly relevant for cervical cancer and immune evasion research.
IDO1 catalyzes the first, rate-limiting step of the kynurenine pathway, oxidizing tryptophan to N-formylkynurenine, leading to production of kynurenine, 3-hydroxykynurenine, 3-hydroxyanthranilic acid, quinolinic acid, and NAD+. Expression is induced by IFN-??, STAT1, IRF1, NF-??B, TLR agonists, prostaglandin E2, and signals from CTLA-4 and CD28. Elevated IDO1 depletes tryptophan, activating GCN2 and inhibiting mTOR to suppress effector T-cells, while kynurenine engages AhR to promote regulatory T-cell differentiation, fostering immune tolerance. The enzyme requires a heme cofactor and interacts with ubiquitin ligase complexes modulating its stability; downstream processing involves KMO and kynureninase. This pathway is central to tumor immune escape across multiple cancer types.
In HeLa cells, although IDO1 is not constitutively expressed, it is strongly induced by inflammatory cytokines, reflecting the immune-driven upregulation in cervical tumors. The HPV-dependent inactivation of p53 and Rb creates a cellular environment susceptible to metabolic immune checkpoint modulation. Thus, IDO1 knockout in HeLa cells enables dissection of tumor-intrinsic immune suppression mechanisms, providing a relevant model to examine how tryptophan metabolism influences T-cell fate and the response to IDO1-targeted therapies.
Key applications include cancer immunology, T-cell co-culture suppression assays, and IDO1 inhibitor screening (e.g., epacadostat). Representative methods are HPLC-MS for kynurenine/tryptophan quantification, flow cytometry for T-cell proliferation and apoptosis markers, AhR luciferase reporters, Western blot, RT-qPCR, and cytokine ELISA. The polyclonal knockout model is also suited for combination drug testing and tumor microenvironment studies in a genetically diverse population. For further information, contact Ascent Research.
