The CASP4 Knockout K-562 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal human cell population with targeted disruption of the CASP4 gene. This product comprises a heterogeneous pool of K-562 cells harboring Cas9-mediated loss-of-function edits, avoiding clonal selection artifacts and enabling bulk functional analyses. CASP4 encodes a key inflammatory caspase involved in innate immunity, and its knockout provides a valuable model for dissecting non-canonical inflammasome activation and pyroptosis pathway.
The parental K-562 cell line was derived from a pleural effusion of a 53-year-old female with chronic myelogenous leukemia (CML) in blast crisis. K-562 is a widely utilized suspension cell line exhibiting erythroid differentiation potential and high sensitivity to natural killer (NK) cell killing, making it a staple in leukemia research and hematopoietic studies. The CASP4 knockout derivative maintains these background characteristics, permitting investigation of inflammatory caspase signaling in a CML context.
CASP4 functions as an intracellular sensor for cytosolic lipopolysaccharide (LPS) from Gram-negative bacteria. Upon LPS binding, CASP4 oligomerizes and becomes proteolytically active, directly cleaving gasdermin D (GSDMD) to trigger pyroptotic cell death. This cascade is regulated by NF-??B, IFNG, and TNF signaling, and involves interactions with the adaptor protein PYCARD (ASC). Active CASP4 also stimulates secondary NLRP3 inflammasome activation and caspase-1-mediated maturation of interleukin-1?? (IL-1??) and IL-18. Key pathway components include LPS, CASP4, GSDMD, NLRP3, PYCARD, CASP1, IL1B, and IL18.
Ablation of CASP4 in the K-562 CML background offers a unique platform to study the interplay between pyroptosis and leukemic cell survival. K-562 cells, originating from blast crisis, often exhibit dysregulated apoptosis and may show altered sensitivity to inflammatory death pathways. The CASP4 knockout model allows researchers to specifically interrogate the non-canonical inflammasome in leukemia, with potential relevance to sepsis, endotoxic shock, and cancer-associated inflammation.
These polyclonal knockout cells are suitable for numerous experimental applications, including LPS-triggered inflammasome activation assays assessed by LDH release, GSDMD cleavage western blotting, and immunofluorescence for membrane pore formation. Cytokine outputs such as IL-1?? can be measured by ELISA, while RT-qPCR can quantify CASP4 and IL1B transcript levels. Co-immunoprecipitation studies confirm CASP4-LPS interactions, and flow cytometry detects pyroptotic cell death. The cells also provide a reproducible system for genetic or chemical screens targeting non-canonical inflammasome regulators. For further information, please contact Ascent Research.
