The CD300LF Knockout HAP1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population designed for loss-of-function analysis of the CD300LF gene. This heterogeneous pool of HAP1 cells harbors targeted gene disruptions, enabling robust depletion of CD300LF protein without the need for clonal isolation. The product is suited for investigating CD300LF-mediated regulatory mechanisms in immunology, signal transduction, and drug discovery applications.
HAP1 is a near-haploid human cell line derived from the KBM-7 chronic myeloid leukemia isolate. As an adherent cell line with a largely haploid genome, HAP1 provides a simplified genetic background that facilitates complete knockout of target genes. The cells retain key myeloid signaling pathways and are an established model for functional genomics and high-throughput knockout screening.
CD300LF is an ITIM-containing inhibitory receptor that recognizes phosphatidylserine exposed on apoptotic cells and activated mast cells. Ligand engagement triggers phosphorylation of ITIM motifs by Src family kinases such as Lyn, leading to recruitment of SHP-1 and SHP-2 phosphatases. These phosphatases dephosphorylate signaling molecules including Syk, LAT, and PLC??2, thereby attenuating calcium mobilization, the PI3K/AKT pathway, and MAPK/NF-??B signaling. Consequently, CD300LF negatively regulates myeloid activation, mast cell degranulation, and cytokine production. Receptor expression can be modulated by cytokines IL-4 and IL-13, and signaling is modulated by adaptor proteins Grb2, DOK1, and SHIP.
Knockout of CD300LF in HAP1 cells offers a clean genetic system to examine how loss of this inhibitory checkpoint reshapes myeloid cell signaling. Given the CML origin of HAP1, the model is relevant for studying deregulated immune receptor pathways in myeloid malignancies. Ablation of CD300LF is expected to relieve ITIM-mediated repression, potentially enhancing activating responses from ITAM-coupled receptors and revealing mechanisms of immune homeostasis.
The CD300LF knockout cells are amenable to a range of functional assays, including Western blotting for protein expression verification, flow cytometry for receptor profiling, degranulation quantification by ??-hexosaminidase release, calcium-flux measurements, and phospho-protein analysis of Syk and SHP-1. Cytokine secretion assays and apoptosis recognition experiments further dissect pathway consequences. These tools support research in allergic inflammation, autoimmune disease, mast cell biology, and immunomodulatory drug target screening. For additional technical details, please contact Ascent Research.
