The CD274 Knockout T-47D Polyclonal Cells are a CRISPR/Cas9-edited polyclonal population of the human breast ductal carcinoma cell line T-47D, genetically engineered for disruption of CD274, the gene encoding programmed death-ligand 1 (PD-L1). This polyclonal knockout pool, generated by CRISPR/Cas9-mediated target-gene disruption, provides a heterogeneous loss-of-function model for studying PD-1/PD-L1 immune checkpoint biology in an estrogen receptor-positive (ER+) cellular context.
T-47D was established from the pleural effusion of a 54-year-old female with invasive ductal carcinoma. It retains expression of estrogen receptor (ER), progesterone receptor (PR), and androgen receptor (AR), and harbors wild-type TP53, classifying it as a luminal A breast cancer line. Widely used to model hormone-responsive breast cancer, T-47D offers a clinically relevant background for investigating tumor immune evasion, as its growth and gene expression programs are influenced by steroid hormones.
CD274 encodes the transmembrane glycoprotein PD-L1, which binds its cognate receptor PD-1 (PDCD1) on activated T cells. PD-L1 transcription is stimulated by interferon-gamma (IFN-??) and tumor necrosis factor-alpha (TNF-??) via STAT3 and NF-??B signaling, and is additionally regulated by MYC and HIF-1??. Upon PD-1 engagement, PD-L1 triggers SHP-2 phosphatase activity, leading to dephosphorylation of ZAP-70 and LCK and consequent attenuation of PI3K/AKT and RAS/RAF/MEK/ERK cascades. This signaling blockade inhibits transcription factors NFAT, AP-1, and NF-??B, suppressing IL-2 production and T-cell proliferation. PD-L1 also interacts with CD80 (B7-1), broadening its immunomodulatory roles.
In the T-47D background, PD-L1 knockout eliminates a critical arm of tumor-intrinsic immune suppression, enabling restoration of effector T-cell function in co-culture assays. The ER+/luminal A identity and wild-type p53 status of T-47D create a genetically defined model for dissecting PD-L1 function without confounding mutations in tumor suppressor pathways. The polyclonal nature of this knockout population preserves cellular heterogeneity, offering a more representative system for evaluating PD-L1 biology in hormone-sensitive breast cancer.
These CD274 knockout T-47D cells are ideally suited for mechanistic studies of PD-L1 signaling, high-throughput immune checkpoint inhibitor screening, and functional analyses of tumor?CT cell interactions. Knockout validation can be performed by flow cytometry, Western blotting, or RT-qPCR, while downstream functional readouts include T-cell proliferation assays, IL-2 and IFN-?? ELISA, and transcriptomic profiling via RNA-seq. The model supports both basic immunology and translational drug discovery efforts. For additional information or custom inquiries, please contact Ascent Research.
