The CD320 Knockout Jurkat Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal knockout cell population derived from the Jurkat human T lymphocyte cell line, designed to disrupt the CD320 gene. This model provides a loss-of-function system for studying the receptor-mediated uptake and cellular trafficking of vitamin B12 (cobalamin), without implying clonal selection or specific editing outcomes. The polyclonal format preserves genetic heterogeneity while enabling pooled analysis of CD320-dependent processes, making it suitable for assays that average across populations or investigate variability in knockout effects. Researchers can employ this tool to dissect CD320 contributions to cobalamin homeostasis and downstream metabolic pathways in a well-characterized immortalized T-cell background.
Jurkat cells are a suspension-adapted human T lymphocyte line originally isolated from a patient with acute T lymphoblastic leukemia. These cells harbor a well-documented PTEN deficiency, which perturbs phosphoinositide 3-kinase signaling and influences cell survival, proliferation, and metabolic regulation. Jurkat cells are widely used as a model for T-cell receptor signaling, apoptosis, and immune responsiveness due to their robust growth, ease of transfection, and responsiveness to external stimuli. Their leukemic origin and PTEN-null status additionally make them valuable for cancer metabolism studies, where altered nutrient uptake and utilization intersect with oncogenic signaling. In this context, CD320 knockout interrogates how vitamin B12 availability impacts T-cell function and malignant transformation.
CD320 functions as a high-affinity surface receptor for the transcobalamin II (TCN2)-vitamin B12 (holo-TCII) complex, initiating its clathrin-mediated endocytosis and subsequent lysosomal release of free cobalamin. Once internalized, cobalamin acts as an essential cofactor for two intracellular enzymes: methionine synthase (MTR), which catalyzes the remethylation of homocysteine to methionine, and methylmalonyl-CoA mutase (MUT), which converts methylmalonyl-CoA to succinyl-CoA. These reactions are pivotal nodes connecting one-carbon metabolism, the homocysteine/methionine cycle, and odd-chain fatty acid catabolism. Consequently, CD320 sits upstream of multiple metabolic branches, with its disruption predictably impairing flux through MTR- and MUT-dependent pathways, leading to accumulation of homocysteine and methylmalonic acid, and limiting methionine synthesis.
In Jurkat T cells, CD320-dependent cobalamin delivery is particularly relevant because lymphocytes require active one-carbon metabolism to support proliferation, nucleotide biosynthesis, and epigenetic regulation. Knockout of CD320 in this leukemic background allows investigation of how impaired vitamin B12 handling influences T-cell activation, viability, and metabolic reprogramming. Given the PTEN-null context, this model may reveal synthetic vulnerabilities or compensatory mechanisms that arise when a tumor suppressor-deficient cell faces nutrient stress. It also offers a controllable system to mimic vitamin B12 deficiency disorders, such as methylmalonic aciduria or megaloblastic anemia, at the cellular level, enabling mechanistic studies without confounding systemic factors.
This knockout cell product supports a range of experimental applications, including quantitative vitamin B12 uptake assays, flow cytometric assessment of receptor surface expression, and metabolic profiling of homocysteine and methylmalonic acid by mass spectrometry or enzymatic methods. Combined with proliferation assays and RNA-seq transcriptomics, researchers can dissect the transcriptional and functional consequences of CD320 loss under defined cobalamin concentrations. The model is also amenable to drug delivery studies targeting the CD320 receptor for cancer therapeutics or to correct metabolic imbalances. For researchers exploring vitamin B12 transport, T-cell immunometabolism, or inherited metabolic diseases, these polyclonal knockout cells provide a versatile platform. For further information, please contact Ascent Research.
