CYB561A3 Knockout THP-1 Cell Line

The CYB561A3 Knockout THP-1 Cell Line is a CRISPR/Cas9-edited human knockout cell line engineered for loss-of-function studies of the CYB561A3 gene. This product provides a stable, genomically disrupted THP-1 monocytic model with targeted inactivation of CYB561A3, enabling investigation of its role in iron metabolism and redox homeostasis. The cell line is suitable for a broad range of in vitro experiments, including functional rescue and pathway analysis, without the need for transient gene silencing reagents.

The THP-1 cell line is a well-characterized human acute monocytic leukemia cell line widely used as a monocyte/macrophage model in innate immunity and inflammation research. Derived from a patient with acute monocytic leukemia, THP-1 cells retain many features of primary monocytes and can be differentiated into macrophage-like cells upon treatment with phorbol esters such as PMA. This host background is particularly valuable for exploring iron handling in phagocytic and antigen-presenting cells, as well as for studying leukemogenesis and immune cell signaling.

CYB561A3 encodes a transmembrane ascorbate-dependent ferric-chelate reductase that reduces extracellular Fe3? to Fe2?, a critical step for cellular iron uptake via DMT1. The enzyme couples ascorbate oxidation to iron reduction, and its expression is transcriptionally regulated by HIF1A and iron-responsive element-binding proteins. Downstream, ferrous iron availability supports heme biosynthesis, iron-sulfur cluster assembly, and limits excessive ROS production. Key interacting factors include the transferrin receptor and ferric chelates, while broader pathway components such as ferritin, ferroportin, and cytochrome b561 coordinate cellular iron balance.

In THP-1 monocytic cells, disruption of CYB561A3 perturbs a pivotal gatekeeper of reductive iron uptake, leading to alterations in the labile iron pool, iron-sensing mechanisms, and redox status. Given that macrophages play a central role in iron recycling and innate immune responses, this knockout model allows dissection of how ascorbate-dependent iron acquisition shapes macrophage effector functions, cytokine production, and inflammatory signaling. Moreover, the leukemic background of THP-1 cells makes this line an attractive system for probing iron-dependent vulnerabilities in acute myeloid leukemia, potentially revealing synthetic lethal interactions or metabolic dependencies relevant to disease pathogenesis.

This engineered cell line is designed for a diverse set of advanced applications, including iron uptake assays using calcein-AM fluorescence, Western blotting of ferritin and TFRC levels, and RT-qPCR of iron-responsive genes. Flow cytometry for the labile iron pool and DCFDA-based ROS detection enable precise characterization of oxidative stress phenotypes. PMA-induced differentiation studies further assess the impact of CYB561A3 loss on macrophage function. These tools are ideal for drug screening campaigns targeting iron metabolism disorders, anemia, and leukemia. For further information or technical support, please contact Ascent Research.