The CD274 Knockout Jurkat Polyclonal Cells are a CRISPR/Cas9-edited polyclonal population of Jurkat T cells with targeted disruption of the CD274 gene, encoding the immune checkpoint ligand PD-L1. This heterogeneous knockout pool enables robust loss-of-function studies without clonal selection. Disruption of CD274 abrogates PD-L1 expression, facilitating unambiguous dissection of PD-L1-dependent inhibitory signals.
Jurkat cells are an immortalized human CD4+ T lymphocyte line derived from a 14-year-old male with acute T cell leukemia. Widely used for studying T cell activation, signaling, and apoptosis, Jurkat cells respond robustly to TCR stimulation and upregulate PD-L1 upon activation, making them a relevant model for immune checkpoint research.
CD274 encodes PD-L1, a transmembrane ligand that binds PD-1 (PDCD1) on T cells to deliver inhibitory signals. Upon PD-1 engagement, SHP2 is recruited to dephosphorylate key TCR signaling components including ZAP70 and LCK, thereby suppressing PI3K-AKT and RAS-ERK pathways. This leads to reduced NF-??B activity and diminished secretion of IL-2 and IFN-??. PD-L1 expression is upregulated by IFN-??, IL-10, TNF, STAT3, and HIF1A, linking inflammatory and hypoxic cues to immune inhibition. PD-L1 also interacts with CD80 (B7-1) to mediate reverse signaling.
In Jurkat cells, CD274 knockout removes PD-L1-mediated inhibitory signals from the T cell, enabling analysis of autocrine PD-1/PD-L1 interactions and paracrine cross-talk. As Jurkat cells co-express PD-1 and PD-L1 upon activation, this model is ideal for studying PD-L1 reverse signaling and evaluating how loss of PD-L1 impacts TCR signaling strength, downstream effector pathways, and functional outputs like proliferation and cytokine production. It serves as a critical tool for testing PD-L1-targeted therapies and dissecting T cell exhaustion mechanisms.
Applications include immune checkpoint drug screening, co-culture assays with PD-1-expressing cells, and PD-L1 reverse signaling studies. Representative assays encompass flow cytometry for PD-L1 loss, western blotting for phospho-ERK/phospho-AKT, IL-2 ELISA, CFSE proliferation assays, NF-??B reporter assays, and RT-qPCR for PD-L1 mRNA. These knockout cells enable mechanistic investigations of tumor immune evasion, autoimmune disorders, and chronic infections. For more details, contact Ascent Research.
