The CD274 Knockout Raji Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population derived from the Raji B lymphocyte line, featuring targeted disruption of the human CD274 gene. This gene-edited model provides a constitutive loss-of-function of the encoded programmed death-ligand 1 (PD-L1) protein, enabling investigations into immune checkpoint regulation and tumor immune evasion mechanisms. The polyclonal format ensures a heterogeneous pool of knockout genotypes, reflecting population-level gene disruption without clonal isolation, and is well-suited for functional assays requiring robust, reproducible PD-L1 ablation.
Raji cells are an Epstein-Barr virus (EBV)-positive Burkitt’s lymphoma B cell line widely employed as a model for B lymphocyte biology, including antibody production, antigen presentation, and immune regulation. These suspension-adapted cells retain key features of mature B cells and are responsive to cytokines and immune cues. Their transformed phenotype, rapid proliferation, and well-characterized signaling networks make them a versatile host for studying lymphomagenesis, immunotherapy, and the tumor microenvironment.
CD274 encodes PD-L1, a type I transmembrane immune checkpoint ligand that engages its cognate receptor PD-1 (PDCD1) on T cells, as well as the costimulatory molecule CD80 (B7-1). PD-L1 expression is transcriptionally activated by upstream regulators including interferon-gamma (IFNG), STAT3, NF-??B, MYC, and HIF1A. Upon PD-1 binding, PD-L1 recruits SHP2 phosphatase, which dephosphorylates key TCR-proximal kinases such as ZAP70 and LCK, thereby attenuating downstream PI3K/AKT/mTOR and RAS/ERK signaling cascades. This results in diminished NFAT and NF-??B transcriptional activity, suppressing T cell activation, proliferation, and effector cytokine production (e.g., IL-2 and IFNG).
In the Raji host cell context, constitutive PD-L1 expression contributes to immune evasion by inhibiting anti-tumor T cell responses, a hallmark of aggressive B cell lymphomas and many solid tumors. CD274 knockout in these polyclonal cell populations abrogates this inhibitory signal, rendering the lymphoma cells more susceptible to T cell-mediated cytotoxicity. This knockout model is thus a powerful tool for dissecting PD-1/PD-L1 axis-mediated immune suppression, evaluating T cell exhaustion in co-culture systems, and assessing the efficacy of therapeutic immune checkpoint blockers.
Researchers can employ these CD274 knockout cells in a variety of experimental workflows, including flow cytometry for surface PD-L1 validation, western blotting for protein expression, co-culture with T cells followed by IFN-?? ELISA, PD-1/PD-L1 binding assays, RT-qPCR for transcriptional analysis, and drug sensitivity studies with anti-PD-L1 antibodies. Applications span immune checkpoint blockade research, tumor microenvironment modeling, T cell exhaustion studies, lymphoma immunotherapy development, and PD-L1/PD-1 inhibitor screening. For further inquiries regarding product specifications or customization, please contact Ascent Research.
