The CCL15 Knockout HAP1 Polyclonal Cells product provides a CRISPR/Cas9-edited polyclonal knockout cell population in which the human CCL15 gene has been disrupted to eliminate functional chemokine expression. This polyclonal format, derived from pooled genetically modified cells, offers a robust loss-of-function model for interrogating CCL15-dependent biological processes. The knockout is generated via CRISPR/Cas9-mediated gene disruption of the CCL15 locus, resulting in a heterogeneous population of HAP1 cells that uniformly lack CCL15 protein production without the need for single-cell clonal isolation. This product is suited for high-throughput functional genomics and screening applications where a stable knockout pool is advantageous, enabling studies of chemokine signaling dynamics in a physiologically relevant near-haploid background.
The host cell line, HAP1, is a near-haploid human cell line originally derived from the KBM-7 chronic myeloid leukemia line. These cells exhibit an adherent, fibroblast-like morphology and are widely recognized for their utility in CRISPR-based knockout experiments due to their haploid genetic background, which simplifies the generation of complete loss-of-function alleles without the complication of compensating wild-type alleles. The HAP1 line retains key components of the chemokine signaling machinery, making it an appropriate platform for studying inflammatory pathways. Its stable karyotype and facile transfectability further enhance its suitability for targeted genome editing and subsequent phenotypic analyses.
CCL15 (also known as leukotactin-1 or MIP-5) is a CC chemokine that functions as a potent chemoattractant for monocytes, eosinophils, and basophils through binding to the chemokine receptors CCR1 and CCR3. Upon ligand-receptor engagement, CCL15 activates downstream effectors including G-proteins, PI3K, Akt, and the MAPK/ERK cascade, leading to calcium mobilization and directed cell migration. Its expression is positively regulated by inflammatory stimuli such as IL-4, IL-13, TNF-alpha, IL-1, and LPS, placing CCL15 within the broader context of cytokine-cytokine receptor interactions and leukocyte transendothelial migration pathways. CCL15 also interacts with heparin and CD74, indicating multifaceted roles in immune regulation. In the knockout model, the absence of CCL15 disrupts these signaling axes, providing a clean background to assess the contribution of this chemokine to inflammatory and migratory responses.
In the context of the HAP1 host cell, CCL15 knockout allows for specific dissection of chemokine-mediated signaling without interference from other endogenous chemokines that might compensate in diploid cell models. The near-haploid state ensures that the loss-of-function is uniform across the population, enhancing the reproducibility of experimental outcomes. Given that HAP1 cells retain functional CCR1 and CCR3 receptors and associated downstream signaling components, this model is especially valuable for examining CCL15-driven receptor activation, calcium flux, and ERK phosphorylation. It serves as a precise tool to validate the role of CCL15 in chemotactic signaling and to differentiate CCL15-specific effects from those mediated by other chemokines that may also engage these receptors.
This CCL15 knockout cell model is suitable for a wide range of applications in immunology and drug discovery, including studies of chemokine signaling in inflammatory diseases, functional genomic screens of cytokine networks, and validation of CCR1/CCR3 antagonists. Representative assays compatible with this model include Western blotting to confirm CCL15 deficiency, RT-qPCR analysis of chemokine gene expression, calcium flux assays to measure receptor activation, phospho-ERK analysis for downstream signaling, Transwell migration assays to assess chemotactic responses, and flow cytometry for receptor expression profiling. By providing a genetically defined polyclonal knockout population, this product enables robust and scalable experimental designs for both mechanistic research and therapeutic target assessment. For further information, please contact Ascent Research.
