The CD274 Knockout LoVo Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population originating from the human LoVo colorectal adenocarcinoma cell line, with targeted disruption of the CD274 gene that encodes the PD-L1 immune checkpoint ligand. This genetic modification ablates surface PD-L1 expression, removing the capability of tumor cells to engage the inhibitory PD-1 receptor on T cells, and provides a polyclonal pool suitable for functional studies without clonal artifacts.
LoVo cells were established from a metastatic lymph node of a colorectal adenocarcinoma patient and are widely used as a model of metastatic colorectal cancer. These cells exhibit rapid proliferation, invasive potential, and carry mutations common in colorectal tumors, such as in KRAS and TP53, which contribute to their aggressive phenotype. This genetic background makes LoVo a relevant host for knockout models aimed at studying late-stage disease and tumor?Cimmune interactions.
CD274 encodes PD-L1, an immune checkpoint ligand that binds PD-1 (PDCD1) and CD80 on T cells, delivering inhibitory signals that suppress T-cell effector functions and promote immune evasion. Ligand binding recruits SHP2 phosphatase, which dephosphorylates key T-cell receptor signaling kinases ZAP70 and LCK, leading to attenuation of PI3K/AKT and RAS/MAPK pathway activities. This cascade drives T-cell exhaustion, reducing cytokine production and cytotoxicity. PD-L1 expression is transcriptionally up-regulated by IFNG through STAT1 and STAT3, as well as by MYC and HIF1A under hypoxic conditions. In the knockout, absence of PD-L1 prevents SHP2 recruitment and preserves T-cell activation signaling, thereby disrupting the PD-1/PD-L1 immune checkpoint axis.
In the LoVo metastatic colorectal adenocarcinoma context, PD-L1-mediated immune evasion is a pivotal mechanism. Knocking out CD274 removes the primary ligand for the PD-1 receptor, providing a clean loss-of-function model to study reactivation of T-cell anti-tumor responses. This is especially relevant for understanding immune checkpoint resistance in advanced colorectal cancer and investigating the tumor?Cimmune synapse in a system with endogenous metastatic features. The polyclonal nature of the edited population reflects the genetic heterogeneity of PD-L1 loss in patient tumors, enabling more robust screening applications.
These polyclonal knockout cells are ideal for a range of immuno-oncology applications, including PD-1/PD-L1 blockade studies, T-cell co-culture cytotoxicity assays, and analysis of the colorectal tumor microenvironment. They facilitate drug candidate evaluation targeting the PD-L1 axis, downstream signaling analysis, and combination therapy screens. Standard characterization methods include western blotting, flow cytometry, RT-qPCR, ELISA for IFN-gamma, and immunofluorescence. For detailed product information and technical support, contact Ascent Research.
