The CCR9 Knockout HAP1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population generated from the HAP1 cell line, a near-haploid human cell model widely employed for genetic loss-of-function studies. This polyclonal knockout cell population provides a versatile loss-of-function model to study the CCR9 chemokine receptor in lymphocyte migration, intestinal homing, and associated signaling networks.
The HAP1 host cell line originates from the KBM-7 chronic myeloid leukemia cell line and retains a near-haploid karyotype in a male genetic background. This near-haploid nature simplifies CRISPR/Cas9-mediated gene editing by reducing target allele complexity, thereby increasing the efficiency of generating knockout cell populations. HAP1 cells grow adherently and are compatible with a wide range of functional assays, including chemotaxis, adhesion, and signaling studies, making them a preferred model system for reproducible genetic perturbation experiments.
CCR9 encodes a G protein-coupled receptor that specifically binds the chemokine ligand CCL25, functioning as a critical mediator of T cell homing to the intestinal mucosa. Upon CCL25 binding, CCR9 activates heterotrimeric G??i/o proteins, triggering PLC-mediated calcium mobilization and downstream phosphorylation cascades involving the MAPK/ERK and PI3K/AKT pathways. These signals promote integrin ??4??7 activation and actin polymerization, facilitating firm adhesion to MAdCAM-1 and directed migration. Additionally, CCR9 interacts with ??-arrestin and JAK kinases, and its expression is regulated by TCF-1 and IL-7.
In the non-hematopoietic HAP1 background, disruption of CCR9 eliminates cellular responses to CCL25, providing a simplified system to dissect CCR9-dependent signaling modules without confounding contributions from other lymphocyte-associated chemokine receptors. This knockout model is valuable for validating pharmacological inhibitors of the CCL25-CCR9 axis, a pathway implicated in inflammatory bowel disease, celiac disease, graft-versus-host disease, and colorectal cancer metastasis. The HAP1 model also supports reconstitution experiments with wild-type or mutant CCR9 to map functional domains and investigate receptor trafficking.
These CCR9 knockout polyclonal cells support diverse applications, including chemotaxis assays to quantify directed cell migration, flow cytometry-based receptor surface expression and ligand binding studies, calcium flux assays to measure immediate signaling responses, adhesion assays to evaluate integrin-dependent attachment, and western blotting to assess pathway activation. The cells are suitable for high-throughput screening of CCR9 antagonists, investigation of GPCR regulation and trafficking, and migration/invasion assays to study cancer cell dissemination. For further technical details or to inquire about product support, please contact Ascent Research.
