The CD22 Knockout THP-1 Cell Line is a CRISPR/Cas9-edited human monocytic leukemia cell line with targeted disruption of the CD22 gene. This knockout model serves as a rigorous negative control for CD22-dependent signaling research and facilitates studies of CD22-independent monocyte/macrophage functions. Supplied as a suspension culture, it is suitable for diverse in vitro assays in immunology and oncology.
THP-1 was derived from the peripheral blood of a 1-year-old male with acute monocytic leukemia (AML M5). As a suspension cell line, it is a classic model for monocyte/macrophage differentiation, phagocytosis, cytokine production, and leukemogenesis. Its robust responses to stimuli such as phorbol esters and lipopolysaccharide make it a versatile platform for innate immune and inflammation research.
In B cells, CD22 functions as an inhibitory co-receptor that attenuates B-cell receptor (BCR) signaling by recruiting the phosphatases SHP-1 and SHIP-1. CD22 binds sialylated glycoproteins and is activated by BCR engagement, leading to suppression of downstream kinases including LYN, SYK, and BLNK, and dampening of PLC??2?Cmediated calcium flux and NF-??B activation. CD22 also interacts with CD45, Grb2, and IgM to fine-tune immune tolerance. Since THP-1 cells lack endogenous CD22 expression, this knockout provides a clean genetic background for assessing CD22-specific reagents and for studying myeloid immune mechanisms without CD22 interference.
The CD22 knockout in the THP-1 background offers a well-matched negative control for experiments probing CD22 biology, B-cell malignancies, and immunotherapeutic targeting. It enables stringent validation of anti-CD22 antibody specificity in flow cytometry and Western blotting, and supports benchmarking of CRISPR editing efficiency. Additionally, this model allows dissection of monocyte/macrophage functions??such as phagocytosis and cytokine secretion??in the absence of CD22-related confounding factors, thereby yielding clearer insights into myeloid contributions to leukemia and inflammation.
Key applications include validation of CD22-targeted therapies, negative control in B-cell functional assays, CRISPR knockout efficiency testing, and myeloid lineage immune profiling. Compatible assays encompass Western blotting for CD22 and phospho-proteins, RT-qPCR, flow cytometry, phagocytosis assays, cytokine ELISA, MTT cytotoxicity testing, and RNA-seq. By employing this cell line, researchers can delineate CD22-dependent and -independent pathways in autoimmune diseases, lymphomas, and immune checkpoint research. For additional technical details, contact Ascent Research.
