The CD274 Knockout Ca Ski Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population featuring targeted disruption of the CD274 gene. Derived from the Ca Ski human cervical carcinoma cell line, this product provides a heterogeneous loss-of-function model for PD-L1, a key immune checkpoint ligand. The polyclonal nature ensures representation of diverse editing outcomes, enabling robust functional studies without reliance on a single clonal isolate. This knockout model is designed for researchers investigating PD-L1-mediated immune evasion mechanisms, particularly in the context of HPV-associated malignancies.
The host cell line, Ca Ski, is an adherent epithelial line originally isolated from a metastasis in the small bowel of a patient with cervical carcinoma. These cells harbor an integrated HPV-16 genome and constitutively express the E6 and E7 oncoproteins, which drive carcinogenic transformation and modulate host immune responses. Ca Ski cells endogenously express PD-L1, making them a physiologically relevant platform for dissecting how viral oncogenes interface with immune checkpoint pathways. Their adherent morphology and established culture protocols facilitate a wide range of in vitro assays.
CD274 encodes programmed death-ligand 1 (PD-L1), a transmembrane protein that engages the PD-1 receptor on T cells to deliver inhibitory signals. Upon binding, PD-L1 recruits the phosphatase SHP2 (PTPN11), which dephosphorylates key proximal T cell receptor signaling molecules, notably ZAP70. This action attenuates downstream PI3K/AKT and RAS/ERK cascades, culminating in reduced T cell proliferation, diminished IL2 production, and enhanced apoptosis. PD-L1 expression is upregulated by interferon-gamma (IFNG) via the STAT1/IRF1 axis, as well as by NFKB, MYC, and HIF1A. PD-L1 also interacts with CD80 and modulates CTLA4 pathways, integrating multiple immunoregulatory circuits.
In the Ca Ski background, PD-L1 is driven by both HPV oncoproteins and inflammatory signals, recapitulating the immunosuppressive microenvironment of cervical tumors. Disruption of CD274 in this polyclonal knockout population allows precise interrogation of PD-L1’s role in shielding cancer cells from T cell-mediated killing. Researchers can assess how loss of PD-L1 affects tumor cell survival, cytokine secretion, and sensitivity to immune effector cells, providing insights into HPV-16-induced carcinogenesis and resistance mechanisms.
These polyclonal knockout cells are invaluable for immune checkpoint blockade studies, co-culture experiments modeling tumor-immune cell interactions, and high-throughput screening of PD-L1 inhibitors. Representative applications include flow cytometric analysis of PD-L1 expression and immune synapse markers, Western blotting for signaling pathway validation, T cell apoptosis assays, ELISA-based cytokine quantification, and anti-PD-L1 drug sensitivity testing. For further technical details or to explore custom cell engineering projects, please contact Ascent Research.
