The CD3E Knockout 143B Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population derived from the human osteosarcoma line 143B. This heterogeneous pool of edited cells eliminates CD3 epsilon protein expression through targeted disruption of the CD3E gene, providing a rapid and robust loss-of-function model without single-cell cloning. The polyclonal nature ensures phenotypic consistency across diverse editing events, collectively abolishing CD3E-dependent activities. Supplied as a ready-to-use reagent, it facilitates comprehensive molecular and functional analyses.
The 143B parental line is a highly metastatic human osteosarcoma model derived from HOS, extensively used for studying bone tumor progression and metastasis in xenograft assays. These cells are characterized by rapid proliferation, anchorage-independent growth, and robust lung metastatic capability in vivo. As CD3E is not natively expressed in osteosarcoma, this knockout background eliminates inadvertent transgene interactions and serves as an ideal platform for ectopic CD3E expression or off-target evaluation of TCR-based therapeutics.
CD3E encodes the CD3 epsilon chain, a vital component of the TCR-CD3 complex that transduces signals from antigen-engaged TCR??/??. Upon phosphorylation by LCK and FYN, CD3E recruits ZAP70, which phosphorylates LAT and SLP-76, leading to PLC??1 activation, calcium flux, and downstream activation of ERK, AKT, and NFAT. The knockout thus abrogates all CD3E-mediated signaling, critical for studying pathways that depend on this scaffold in non-lymphoid backgrounds.
Deleting CD3E in 143B cells generates a clean experimental system for evaluating CD3E biology outside the T-cell lineage. It enables controlled re-expression to dissect structure-function relationships, screens for CD3E-interacting proteins, and safety assessments of anti-CD3 immunotherapies. Moreover, this model facilitates investigation of non-canonical CD3E roles in processes such as cancer cell migration and adhesion, which may contribute to osteosarcoma metastasis.
Typical applications include Western blot and RT?qPCR for knockout validation, immunofluorescence and flow cytometry for protein detection, and functional assays such as proliferation, migration, and xenograft tumor growth to evaluate CD3E-dependent phenotypes. These cells are also suited for co?culture with T cells to study off?target interactions and for proteomic screens to identify novel CD3E binding partners. For additional product information and technical support, please contact Ascent Research.
