The IDO1 Knockout T-47D Polyclonal Cells represent a CRISPR/Cas9-mediated polyclonal knockout cell population in which the IDO1 gene has been disrupted in the T-47D human breast carcinoma cell line. This loss-of-function model enables the study of IDO1??s immunosuppressive functions by abrogating the enzyme??s activity without introducing a defined clonal genotype, preserving genotypic heterogeneity typical of polyclonal pools. The product is supplied as a mix of edited cells, each harboring distinct gene-disruption events, making it suitable for experiments where population-level phenotypes are analyzed.
The parental T-47D cell line is an estrogen receptor-positive (ER+), progesterone receptor-positive (PR+) human ductal breast carcinoma model originally derived from the pleural effusion of a 54-year-old female. Widely used as a model of luminal A breast cancer, T-47D cells retain hormone responsiveness and exhibit characteristic signaling features, including expression of ER-regulated genes. Their relevance to hormone receptor-positive breast cancer makes them a valuable system for investigating tumor-intrinsic immune modulation.
IDO1 (indoleamine 2,3-dioxygenase 1) is an intracellular heme-containing enzyme that catalyzes the rate-limiting step of tryptophan catabolism along the kynurenine pathway, converting L-tryptophan to N-formylkynurenine. This depletes local tryptophan and generates kynurenine, an endogenous AHR agonist. AHR activation in immune cells promotes Treg differentiation and suppresses effector T-cell responses, while tryptophan depletion triggers GCN2 stress kinase, inhibiting T-cell proliferation. IDO1 is regulated by IFNG, IL6, TGFB1, and TLR ligands. Downstream mediators include kynurenine, AHR, GCN2, mTORC1 suppression, and Treg induction. Additional pathway components IL-10 and TGFB reinforce the immunosuppressive microenvironment.
In T-47D ER+ breast carcinoma, IDO1-mediated tryptophan metabolism facilitates immune evasion. IDO1 expression correlates with poor prognosis. These polyclonal knockout cells enable dissection of tryptophan catabolism’s role in modulating immune behavior in the breast tumor microenvironment. The ER+ context also permits exploration of crosstalk between hormonal signaling and immune checkpoints.
These knockout cells are suited for a range of immuno-oncology research applications, including studies of immune checkpoint blockade, T-cell suppression mechanisms, and tumor microenvironment modulation. Representative assays include kynurenine production assays to assess enzymatic activity loss, T-cell proliferation assays in co-culture systems to evaluate immune rescue, flow cytometry for Treg markers (FoxP3, CD25) to monitor regulatory T-cell induction, and RT-qPCR or Western blotting to confirm IDO1 disruption and monitor downstream signaling. Additionally, the cells can be employed in high-throughput screens of IDO1 pathway inhibitors or combination therapies. For further details regarding this product, please contact Ascent Research.
