The CD19 Knockout 786-O Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population designed to disrupt CD19 expression in the 786-O human renal clear cell adenocarcinoma line. This polyclonal format, achieved through CRISPR/Cas9-mediated gene disruption, provides a heterogeneous loss-of-function model for studying CD19-dependent biology and serves as a critical negative control for CD19-targeted immunotherapies.
The 786-O line is a VHL-deficient clear cell renal cell carcinoma model derived from a primary tumor of a 58-year-old male. It carries a VHL frameshift mutation (c.311delG) resulting in constitutive HIF activation and a pseudohypoxic phenotype, while remaining PTEN wild-type. This background is extensively used to investigate VHL/HIF axis biology and renal tumorigenesis.
CD19 is a B-lineage-specific glycoprotein coreceptor for the B-cell receptor (BCR). Upon BCR engagement, Lyn and Fyn phosphorylate CD19, recruiting PI3K p85 and adaptors Vav and Grb2, which activate the PI3K/Akt/mTOR and Ras/MAPK cascades. Downstream, NF-??B is activated, driving expression of MYC and BCL2L1. CD19 collaborates with CD21, CD81, and CD225 to amplify BCR signaling and lower activation thresholds. Aberrant CD19 signaling underlies B-cell malignancies and autoimmune diseases.
In the 786-O background, ectopic CD19 expression allows investigation of CD19-mediated signaling outside the hematopoietic lineage. This knockout model provides an isogenic control to assess CD19-specific effects in the context of VHL-deficient ccRCC, enabling dissection of CD19-dependent versus HIF-driven signaling. It is particularly useful for evaluating off-target activities of CD19-directed therapeutics and for interrogating cross-talk between CD19 pathways and oncogenic signaling networks.
Applications include flow cytometric and Western blot validation of anti-CD19 antibody specificity, co-culture cytotoxicity assays with CD19 CAR-T cells monitored by IncuCyte and cytokine ELISA (IFN-??, IL-2), and transcriptomic profiling to identify CD19-dependent gene signatures. The polyclonal cells are suitable for drug screening and as a negative control in bispecific antibody studies. CRISPR target-site disruption can be confirmed by T7E1 assay and Sanger sequencing. For further information, please contact Ascent Research.
