The KLRB1 Knockout 143B Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population derived from the human 143B osteosarcoma cell line, designed for loss-of-function analysis of the KLRB1 gene. This polyclonal format maintains heterogeneous gene disruption, mimicking natural cellular diversity and reducing clonal bias. The product serves as a robust model to interrogate CD161 receptor functions without the limitations of single-cell cloning.
The parental 143B line is a highly metastatic human osteosarcoma model harboring a TP53 mutation, extensively used in bone cancer and metastasis research. Its aggressive characteristics make it a relevant system for assessing the impact of immune-modulatory gene edits on tumor behavior and immune interactions.
KLRB1 encodes CD161, a C-type lectin-like inhibitory receptor expressed on NK cells and certain T cell subsets. Upon binding to its ligand LLT1 (CLEC2D), CD161 recruits the protein tyrosine phosphatases SHP-1 and SHP-2, which dephosphorylate key signaling intermediates such as ZAP70, thereby attenuating T cell receptor-mediated activation and inhibiting cytotoxic granule exocytosis and cytokine release. Upstream, cytokines including IL-12 and IL-15, as well as T cell receptor engagement, upregulate CD161 expression, integrating immune stimulatory and inhibitory cues. Thus, CRISPR/Cas9-mediated KLRB1 disruption in 143B cells eliminates CD161 surface expression, abolishing the LLT1?CSHP-1/SHP-2 inhibitory axis and potentially unleashing effector functions.
The 143B osteosarcoma cell line, with its TP53 mutation and high metastatic propensity, offers a clinically relevant setting to investigate how CD161 loss affects tumor-immune crosstalk. Because osteosarcomas often express LLT1, the KLRB1 knockout model can be used to examine whether tumor-expressed CD161 directly interacts with LLT1 on immune cells to suppress anti-tumor immunity, or whether it modulates tumor cell autonomous properties such as proliferation and invasion. This makes the model invaluable for studying immune evasion mechanisms and testing therapeutic blockade of the CD161 pathway in bone cancers.
Researchers can utilize flow cytometry to verify CD161 ablation, conduct NK cell-mediated cytotoxicity assays using chromium release or real-time imaging, perform LLT1 binding assays to confirm disrupted interactions, and measure SHP-1/SHP-2 phosphorylation levels by western blot. Additional applications include multiplex cytokine release profiling following LLT1 stimulation, and migration or invasion assays (e.g., transwell, scratch) to evaluate changes in metastatic behavior. These tools facilitate advances in cancer immunotherapy, NK cell biology, signal transduction research, and drug targeting of inhibitory receptors. For further information, please contact Ascent Research.
