The GCHFR Knockout Raji Polyclonal Cells are a CRISPR/Cas9-edited polyclonal population of human B lymphoblasts harboring targeted disruption of the GTP cyclohydrolase I feedback regulator (GCHFR) gene. This loss-of-function model is supplied as a genetically diverse polyclonal pool, avoiding clonal selection artifacts while preserving the native B-cell biology of the Raji host line. The cells provide a robust platform for dissecting tetrahydrobiopterin (BH4)-dependent regulatory networks without clonal bias, suitable for studies requiring realistic cellular heterogeneity.
The Raji cell line originates from a Burkitt lymphoma, an aggressive B-cell malignancy characterized by constitutive NF-??B and MYC activation. Widely used in immunological and cancer research, Raji cells exhibit stable suspension growth and a well-defined transcriptome, making them an effective model for exploring metabolic pathways in a B-lymphocyte context. Their rapid proliferation and documented signaling pathways facilitate high-throughput applications and functional assays linking metabolism to immune cell function.
GCHFR functions as a feedback inhibitor of GTP cyclohydrolase I (GCH1), the rate-limiting enzyme in BH4 biosynthesis, with its inhibitory activity modulated by intracellular BH4 concentrations. In normal physiology, GCHFR restrains GCH1 when BH4 levels are adequate. In these knockout cells, disruption of GCHFR removes this control, causing dysregulated BH4 production. BH4 is an essential cofactor for nitric oxide synthases (NOS) and the aromatic amino acid hydroxylases tyrosine hydroxylase (TH), tryptophan hydroxylase (TPH), and phenylalanine hydroxylase (PAH), placing GCHFR at a junction controlling nitric oxide signaling and neurotransmitter synthesis. Upstream regulators include BH4 itself and inflammatory cytokines, while downstream targets encompass GCH1, NOS, TH, TPH, and PAH.
In the Raji B-cell background, GCHFR knockout enables investigation of cell-autonomous BH4 metabolism outside neuronal or hepatic systems. B lymphocytes possess functional BH4 pathway components, and BH4 influences immune processes such as antibody production and nitric oxide-mediated signaling. The model permits dissection of how unregulated BH4 synthesis impacts redox balance, proliferation, and possibly immunometabolism in a lymphoma setting. The polyclonal nature supports pooled functional genomics and high-content experiments, reflecting population-level responses.
Typical applications include HPLC-based BH4 quantification, Western blot analysis of GCH1 protein expression, nitric oxide detection via Griess or fluorescent assays, and RT-qPCR profiling of downstream hydroxylase genes. This knockout population is well-suited for drug screening to identify BH4 pathway modulators, metabolic flux studies, and functional interrogation of nitric oxide and monoamine pathways in immune cells. For further technical details, please contact Ascent Research.
