The CD47 knockout NCI-H1299 polyclonal cells represent a CRISPR/Cas9-edited polyclonal knockout cell population derived from the NCI-H1299 non-small cell lung carcinoma cell line. This product provides a loss-of-function model for interrogating CD47-dependent biological processes, including immune evasion and integrin-mediated signaling, without altering the endogenous genetic background of the host cells. The polyclonal nature ensures a heterogeneous pool of edited alleles, offering a robust platform for functional studies in cancer biology and immunotherapy research.
The NCI-H1299 host cell line originates from a metastatic lymph node of a lung adenocarcinoma patient, serving as a widely used model for metastatic non-small cell lung cancer. These cells harbor a homozygous deletion of TP53, rendering them p53-deficient, while maintaining wild-type KRAS and EGFR status. This genetic profile is characteristic of a subset of aggressive lung carcinomas, making NCI-H1299 particularly suited for investigating the intersection of oncogenic drivers and immune regulatory mechanisms in a p53-null context.
CD47 functions as a transmembrane protein that transmits a ‘don’t eat me’ signal by engaging the inhibitory receptor SIRP?? on macrophages, leading to phosphorylation of immunoreceptor tyrosine-based inhibitory motifs (ITIMs) and subsequent recruitment of SHP-1 and SHP-2 phosphatases. This signaling cascade suppresses phagocytosis by preventing myosin-II accumulation at the phagocytic synapse. Concurrently, CD47 interacts with integrins such as ??v??3 and ??IIb??3 to promote cell adhesion and migration through focal adhesion kinase (FAK) and PI3K/AKT pathway activation. Upstream regulators include MYC, NF-??B, HIF-1??, TNF-??, and IL-6, while thrombospondin-1 and SIRP?? serve as additional binding partners that modulate CD47 activity.
In the NCI-H1299 background, CD47 knockout eliminates the inhibitory checkpoint on macrophage-mediated clearance, potentially unmasking tumor cells for phagocytosis. Given the p53 deficiency, which can upregulate CD47 expression via MYC or NF-??B as a compensatory survival mechanism, this model enables dissection of how CD47 contributes to immune escape independently of p53 status. Furthermore, the knockout allows researchers to assess CD47’s role in integrin-dependent metastatic behaviors, making it a valuable tool for studying lung adenocarcinoma progression and therapeutic resistance.
Typical research applications include co-culture phagocytosis assays with macrophages to quantify engulfment, evaluation of CD47-blocking antibodies or SIRP??-Fc fusion proteins, and flow cytometry for surface CD47 expression. Downstream signaling analyses via western blotting for SHP-1, FAK, and phosphorylated AKT, along with migration and invasion assays, can delineate integrin-related pathways. Immunofluorescence visualization of myosin-II at the phagocytic synapse and immune checkpoint blockade co-cultures are also facilitated by these cells. For further technical details and ordering information, please contact Ascent Research.
