The AFMID Knockout HEK293T Polyclonal Cells constitute a CRISPR/Cas9-edited polyclonal knockout cell population in human embryonic kidney HEK293T cells, targeting the AFMID gene that encodes arylformamidase. This heterogeneous pool of cells with disrupted AFMID provides a robust loss-of-function model that avoids clonal artifacts, enabling reliable interrogation of the kynurenine pathway.
HEK293T cells are adherent epithelial cells derived from human embryonic kidney tissue, transformed with adenovirus type 5 DNA and stably expressing the SV40 large T antigen. This genetic background confers exceptionally high transfection efficiency and episomal plasmid replication, making the line a workhorse for recombinant protein expression, viral packaging, and a widely adopted model for fundamental cell biology and metabolic studies. Their robust growth and amenability to genetic manipulation render them ideal for examining tryptophan catabolism.
AFMID catalyzes the conversion of N-formylkynurenine to kynurenine, the second enzymatic step in the kynurenine pathway of tryptophan degradation, operating downstream of indoleamine 2,3-dioxygenase 1 (IDO1) and tryptophan 2,3-dioxygenase (TDO2). Its transcriptional activity is induced by interferon gamma, aryl hydrocarbon receptor (AhR), NF-??B, and STAT1, linking immune signals to metabolic output. The kynurenine generated by AFMID is a critical branchpoint metabolite: kynurenine aminotransferases (KAT I?CIII) convert it to kynurenic acid, while kynureninase (KYNU) and downstream enzymes 3-hydroxyanthranilic acid 3,4-dioxygenase (HAAO) and quinolinic acid phosphoribosyltransferase (QPRT) channel it toward quinolinic acid and de novo NAD+ biosynthesis. Thus, AFMID is a central regulator of neuroactive compound production and cellular energy metabolism.
In the HEK293T host, AFMID knockout allows precise dissection of kynurenine pathway flux with minimal confounding tissue-specific regulation. The cell line??s high transfectability facilitates complementation studies with wild-type or mutant AFMID cDNA, supporting structure?Cfunction analysis. Quantitative readouts such as HPLC-MS monitoring of tryptophan and kynurenine levels, ELISA-based kynurenic acid measurement, and NAD+ quantification can directly assess metabolic perturbations. Additionally, the model is suited for studying cell proliferation under tryptophan restriction, a condition relevant to tumor microenvironments where IDO1/TDO2-driven tryptophan depletion suppresses immune cells.
Applications include in-depth analysis of tryptophan metabolism, kynurenine pathway flux, and the role of AFMID in generating immunomodulatory and neuroactive metabolites. The polyclonal knockout pool is valuable for inhibitor screening against enzymes of the kynurenine pathway and for investigating how AFMID loss affects NAD+ homeostasis. Standard techniques encompass western blotting and RT-qPCR for AFMID expression, metabolite profiling by mass spectrometry, and cell-based viability assays under defined tryptophan concentrations. Rescue with wild-type AFMID ensures phenotypic specificity. For technical inquiries and order support, please contact Ascent Research.
