The CD274 Knockout HCT 116 Polyclonal Cells are a mixed population of HCT 116 colorectal carcinoma cells with targeted gene disruption of CD274 via CRISPR/Cas9. This polyclonal knockout pool uniformly lacks PD-L1 expression, providing a robust loss-of-function model for studying PD-1/PD-L1 immune checkpoint biology. By avoiding clonal selection, these cells better preserve population diversity, enabling rigorous assessment of PD-L1-dependent functions in immune evasion.
The parental HCT 116 cell line is a well-characterized model of colorectal carcinoma, harboring an activating KRAS G13D mutation and maintaining mismatch repair proficiency. These features drive constitutive MAPK/ERK signaling and intact DNA repair, recapitulating key aspects of colorectal tumorigenesis. The epithelial phenotype and reproducible growth of HCT 116 cells make them ideal for immune co-culture assays, high-throughput screening, and xenograft tumor models.
CD274 encodes PD-L1, an immune checkpoint ligand that binds PD-1 on T cells, transmitting inhibitory signals that suppress proliferation and effector functions. PD-L1 expression is regulated by upstream factors including IFNG, JAK2, STAT3, MYC, NFKB, HIF1A, and oncogenic KRAS. Upon receptor engagement, PD-L1 activates SHP-2, which dephosphorylates signaling intermediates, leading to PI3K/AKT pathway inhibition and reduced IL-2 production, thereby promoting immune tolerance. In colorectal cancer, this axis contributes to tumor immune escape.
By disrupting CD274, these HCT 116 knockout cells eliminate surface PD-L1, effectively removing a dominant immunosuppressive signal. This loss is expected to enhance T-cell-mediated cytotoxicity and provide a clean system to dissect PD-L1??s role in colorectal cancer immune evasion. The model also enables study of cross-regulation between oncogenic KRAS, STAT3, and the PD-L1 checkpoint, revealing how tumor-intrinsic signaling modifies immune susceptibility.
Research applications include validating PD-L1 inhibitors, profiling immune checkpoint blockade responses, and modeling tumor-immune interactions. Standard assays involve Western blotting and flow cytometry for PD-L1 detection, T-cell co-culture cytotoxicity assays, RT-qPCR and RNA-seq for gene expression, and cytokine release measurements. These cells are also suitable for in vivo xenograft studies coupled with checkpoint inhibitors. For additional information or technical support, contact Ascent Research.
