The CCR4 Knockout HAP1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population designed to ablate CCR4 gene function in the near-haploid HAP1 cell line. This heterogeneous pool of cells carries targeted disruptions at the CCR4 locus introduced by CRISPR/Cas9, resulting in a population-wide loss of CCR4 protein expression. The polyclonal format provides a robust and genetically diverse loss-of-function model that can be used directly in functional assays without clonal selection, offering researchers a practical tool for studying chemokine receptor biology in a genetically tractable background.
The HAP1 host cell line is a near-haploid human chronic myeloid leukemia (CML) cell line with fibroblastoid morphology, derived from KBM-7. Its haploid genome simplifies knockout generation, making it ideal for functional genomics, high-throughput CRISPR screening, and pathway analysis. The CCR4 knockout in this background provides a clean platform to study chemokine receptor function independent of T-cell lineage-specific factors, leveraging the genetic simplicity of the HAP1 system.
CCR4 is a CC chemokine receptor that binds CCL17 and CCL22, mediating Th2 cell chemotaxis. Ligand binding activates G??i, which triggers calcium mobilization via PLC??. Downstream PI3K/AKT and ERK1/2 pathways drive cytoskeletal rearrangements through integrin activation. CCR4 expression is transcriptionally controlled by GATA3 and the IL-4/STAT6 axis, and receptor signaling is regulated by ??-arrestin-mediated desensitization. This signaling cascade underpins the migration of Th2 cells to inflammatory sites.
The CCR4 knockout in HAP1 enables study of receptor signaling independently of T-cell biology. Although HAP1 lacks endogenous T-cell transcription factors like GATA3, heterologous expression can reconstitute regulation. This model facilitates dissection of CCR4-proximal events such as G??i-dependent calcium responses and PI3K/AKT activation. As a companion to wild-type HAP1, the knockout pool is valuable for chemical screens to identify CCR4-targeted molecules, providing unambiguous drug response attribution.
This knockout product is well-suited for a broad range of research applications, including chemokine receptor pharmacology, therapeutic antibody validation, and functional genomics screens. Representative assays include chemotaxis migration assays to assess directional cell movement, calcium flux measurements using fluorescent indicators, and phospho-specific flow cytometry or western blotting to monitor PI3K/AKT and ERK1/2 signaling. Additionally, the polyclonal population can be used in drug sensitivity profiling for CCR4-targeted therapies under investigation for allergic asthma, atopic dermatitis, and cutaneous T-cell lymphoma. For further technical information or customized support, please contact Ascent Research.
