The CBL Knockout Jurkat Polyclonal Cells are a CRISPR/Cas9-edited polyclonal population of Jurkat T lymphocytes with targeted disruption of the CBL gene. This product consists of a heterogeneous pool of edited cells that collectively lack functional CBL protein, circumventing the selective pressure of monoclonal isolation. The polyclonal format preserves functional diversity and is delivered as a ready-to-use knockout model for direct integration into experimental workflows.
The parental Jurkat cell line is an immortalized human T lymphocyte line derived from the peripheral blood of a 14-year-old male with acute T cell lymphoblastic leukemia. Jurkat cells are extensively characterized and widely adopted for mechanistic studies of T cell receptor (TCR) signaling, apoptosis, and leukemogenesis. They exhibit robust responses to immunological stimuli including anti-CD3/CD28 antibodies, making them an ideal host for investigating T cell biology.
CBL encodes an E3 ubiquitin-protein ligase that functions as a critical negative regulator of TCR and receptor tyrosine kinase (RTK) signaling. Upon TCR engagement, Src family kinases LCK and FYN phosphorylate CD3 ITAMs, leading to ZAP70 recruitment and activation. CBL is subsequently recruited to the receptor complex and catalyzes ubiquitination of key substrates, including ZAP70, SYK, and the PI3K regulatory subunit p85, targeting them for lysosomal or proteasomal degradation. CBL interacts with adaptors GRB2, NCK, and SH3KBP1/CIN85 and UBE2D family E2 enzymes, and undergoes autoubiquitination, processes that fine-tune ligase activity. This attenuates signal amplitude and duration, with analogous roles in downmodulating EGFR and PDGFR pathways.
In Jurkat cells, CBL knockout removes a major inhibitory constraint on TCR signaling, resulting in sustained phosphorylation of proximal signaling components and enhanced downstream effector activation. This model is particularly relevant for research into T cell acute lymphoblastic leukemia (T-ALL) and juvenile myelomonocytic leukemia (JMML), where CBL dysregulation is implicated. It provides a genetically defined system to dissect how aberrant ubiquitin-mediated proteolysis contributes to oncogenic transformation and to identify therapeutic targets in lymphoid malignancies.
The polyclonal CBL knockout cells support a wide range of applications, including phospho-signaling analysis by Western blotting for phospho-ZAP70 and phospho-ERK, flow cytometric quantification of activation markers CD69 and CD25, ubiquitination assays, and co-immunoprecipitation for interaction mapping. Functional readouts such as IL-2 secretion, T cell proliferation, and apoptosis provide quantitative measures of T cell responsiveness. The model is also suited for drug screening targeting ubiquitin ligase inhibitors and investigation of immune synapse dynamics. For further information and protocol support, contact Ascent Research.
