The CD19 Knockout 143B Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal knockout cell population derived from the 143B human osteosarcoma cell line. This product consists of a heterogeneous pool of cells in which the CD19 gene has been disrupted through CRISPR/Cas9-mediated gene editing, creating a loss-of-function model system for investigating CD19 biology and therapeutic targeting. Unlike monoclonal knockout lines, this polyclonal format provides a diverse representation of editing outcomes, which can be valuable for studies where clonal homogeneity is not required or for initial screening applications. The cells are delivered as a mixed population, allowing researchers to immediately proceed with functional assays without the need for single-cell cloning.
The parental 143B cell line is a well-characterized human osteosarcoma line originally derived from the HOS (human osteosarcoma) cell line. 143B cells display an osteoblastic phenotype and are known for their high tumorigenicity and metastatic potential in in vivo models. These properties make the 143B line a robust model for bone cancer research and drug discovery studies. Additionally, the line??s rapid proliferation and ease of culture provide a practical foundation for genetic manipulation and high-throughput screening applications.
CD19 is a transmembrane co-receptor essential for B-cell receptor (BCR) signal amplification. Upon BCR engagement, CD19 associates with CD21, CD81, and CD225, and recruits Lyn kinase and PI3K to the membrane. This initiates downstream activation of Akt, BTK, PLC??2, and NF-??B, driving B-cell proliferation and survival. Key upstream regulators include BCR-antigen interaction and IL-4 stimulation. In B-cell malignancies, aberrant CD19 signaling contributes to oncogenesis, highlighting its importance as a therapeutic target.
Although 143B cells lack endogenous CD19 expression, this knockout pool offers a defined null background for ectopic expression and safety profiling of CD19-targeted therapies. It serves as a negative control or a platform to assess off-tumor reactivity of CAR-T cells and bispecific antibodies. The robust growth and transfectability of 143B cells facilitate complementation assays and CRISPR specificity studies, enabling precise dissection of CD19 signaling requirements.
Typical applications include validation of CD19 antibodies by flow cytometry and immunoblotting, RT-qPCR quantification of CD19 transcripts, and functional complementation. These cells are well-suited for co-culture with CD19-directed CAR-T cells to evaluate cytotoxicity and off-target effects, apoptosis assays, and CRISPR off-target analysis via deep sequencing. For additional product details or custom inquiries, please contact Ascent Research.
