The CYTH1 Knockout Raji Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population derived from the Raji B lymphocyte cell line, featuring disruption of the CYTH1 gene. This polyclonal pool provides a loss-of-function model for studying CYTH1-dependent processes without the selection of single-cell clones, maintaining genetic diversity representative of the edited population. The knockout enables investigation of CYTH1??s role in guanine nucleotide exchange factor activity and integrin-mediated cellular functions.
The parental Raji cell line is a human B lymphoblast line originally established from a male patient with Burkitt lymphoma. Raji cells are Epstein?CBarr virus (EBV)-positive and grow in suspension, serving as a well-characterized model for EBV latency, B cell receptor (BCR) signaling, and oncogenic mechanisms in hematological malignancies. Their lymphoblastoid phenotype recapitulates key features of B cell biology, making them suitable for studying adhesion, migration, and immune synapse formation.
CYTH1 encodes cytohesin-1, a guanine nucleotide exchange factor (GEF) that activates ARF small GTPases, principally ARF1 and ARF6, by catalyzing GDP/GTP exchange. Its pleckstrin homology (PH) domain mediates membrane recruitment through binding to phosphatidylinositol (3,4,5)-trisphosphate (PIP3), a product of PI3K signaling. Direct interaction of CYTH1 with the cytoplasmic tail of integrin beta-2 (ITGB2/CD18) promotes conformational activation of LFA-1 (CD11a/CD18), leading to enhanced ligand binding and outside-in signaling. Downstream, activated ARF6 and RAC1 coordinate actin cytoskeleton remodeling via PIP5K, driving processes such as cell adhesion, spreading, and transendothelial migration. Signaling inputs from BCR, chemokine receptors (CXCR4), and CD19 converge on PI3K/PIP3 to regulate CYTH1 localization and activity.
In the Raji B cell context, CYTH1 disruption is particularly relevant for dissecting integrin-dependent adhesion and migration pathways that underpin lymphocyte trafficking and immune surveillance. Since Raji cells endogenously express LFA-1 and exhibit robust adhesion to ICAM-1, ablation of CYTH1 provides a system to interrogate the GEF?Cintegrin coupling required for firm adhesion under flow and transendothelial migration. Furthermore, because EBV latency and BCR signaling drive PI3K/PIP3 production, the CYTH1 knockout model allows investigation of how pathogenic signaling in Burkitt lymphoma co-opts cytohesin-mediated integrin activation to promote lymphoma cell dissemination and microenvironment interactions.
Typical applications of these polyclonal knockout cells include flow cytometry-based monitoring of integrin activation using conformation-specific antibodies against CD18/CD11a, static and flow adhesion assays on ICAM-1 substrates, transwell migration assays toward chemokines such as SDF-1??, and immunoprecipitation to detect ARF-GTP loading. The cells are also suited for high-content imaging of F-actin dynamics, western blotting for PI3K/AKT pathway effectors, and RNA-seq to identify transcriptomic changes upon CYTH1 loss. For further details on this product, please contact Ascent Research.
