The CD300LD Knockout NCI-H1299 Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal knockout cell population in which the CD300LD gene has been disrupted to generate a heterogeneous loss-of-function model. This polyclonal format avoids clonal selection artifacts and provides a pool of edited cells suitable for functional studies examining the role of CD300LD in immune regulation and tumor cell biology.
The NCI-H1299 host cell line is a lung adenocarcinoma line derived from a lymph node metastasis, characterized by a p53 null genotype and adherent epithelial morphology. As a widely utilized non-small cell lung cancer (NSCLC) model, it offers a relevant background for studying tumor-intrinsic immune evasion mechanisms, particularly given its metastatic origin and deficiency in p53-mediated pathways.
CD300LD is an ITIM-containing inhibitory receptor that recognizes phosphatidylserine exposed on apoptotic cells and stressed cells. Ligand engagement leads to recruitment and activation of the tyrosine phosphatases SHP-1 and SHP-2, as well as the inositol phosphatase SHIP-1, which collectively dephosphorylate key signaling intermediates downstream of activating receptors. This results in downregulation of PI3K-AKT and NF-??B pathways, thereby impairing pro-inflammatory cytokine production and phagocytosis. The receptor is also modulated by cytokines such as IL-4 and IFN-??, and TLR ligands.
In the NCI-H1299 background, disruption of CD300LD enables detailed investigation of its contribution to immune checkpoint function and apoptotic cell clearance in lung adenocarcinoma. The p53 null status of this line shifts dependency to alternative signaling networks, making it a valuable system to dissect how CD300LD-mediated inhibitory signals regulate tumor-immune interactions and inflammation within the tumor microenvironment.
This polyclonal knockout population is amenable to a wide range of experimental assays. Co-culture with macrophages can assess phagocytosis of apoptotic cells, while ELISA quantifies effects on IL-6 and TNF-?? secretion. Western blot analysis of CD300LD expression and SHP-1/SHP-2 phosphorylation confirms disruption and pathway activity, and flow cytometry evaluates phosphatidylserine binding. Additionally, proliferation, migration, and invasion assays can reveal the impact of CD300LD loss on tumor cell behavior. For technical inquiries, please contact Ascent Research.
