The CD19 Knockout DLD-1 Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal knockout cell population derived from the human DLD-1 colorectal adenocarcinoma epithelial cell line, with targeted disruption of the CD19 gene. This loss-of-function model is provided as a heterogeneous pool of edited cells, suitable for applications such as CRISPR control experiments and pooled phenotypic screens.
The parental DLD-1 cell line is a well-established model of colorectal cancer, originating from a Duke’s type C adenocarcinoma. It exhibits an epithelial morphology and bears mutations in key oncogenes and tumor suppressors including APC, KRAS, and TP53, recapitulating molecular features of colorectal carcinogenesis. DLD-1 cells grow adherently and are amenable to transfection, lentiviral transduction, and standard cell-based assays, making them a versatile tool for cancer research.
In its native B-cell context, CD19 functions as a co-receptor for the B-cell receptor (BCR), where it is phosphorylated by Lyn tyrosine kinase upon BCR engagement. It subsequently assembles a signalosome with CD21 (complement receptor 2) and CD81 (TAPA-1), recruiting the p85 regulatory subunit of PI3K, the adaptor Grb2, and the kinases Vav and Syk. This leads to downstream activation of PLC??2, Akt, ERK, and NF-??B signaling cascades, which collectively lower the threshold for B-cell activation and are essential for B-cell development, proliferation, and antibody responses. The transcription factor Pax5 and IL-4 receptor signaling positively regulate CD19 gene expression. While CD19 is not endogenously expressed in DLD-1 colorectal cells, ectopic expression systems are often employed to reconstitute these signaling pathways for mechanistic studies.
The engineered deletion of CD19 in DLD-1 cells provides a defined genetic background that eliminates any residual or off-target effects of CRISPR components targeting CD19, making it an ideal parental line for ectopic expression and complementation studies. This model is particularly valuable for evaluating the specificity of CD19-directed cancer immunotherapies, such as chimeric antigen receptor (CAR) T-cell therapies, in a non-hematopoietic cellular environment. It also enables investigation of potential crosstalk between B-cell signaling modules and epithelial cancer cell pathways.
Researchers can utilize these polyclonal knockout cells for a variety of applications, including B-cell signaling pathway reconstitution, off-target analysis in CRISPR experiments, and target validation for immunotherapy development. Typical experiments involve flow cytometric confirmation of CD19 protein absence, RT-qPCR for transcript quantification, and Sanger sequencing to verify gene disruption. Functional assays may include measurement of phosphorylated Akt (Ser473) or ERK (Thr202/Tyr204) following stimulation, as well as proliferation and viability assays. For additional technical information, please contact Ascent Research.
