Description

The ERAP1 Knockout K562 Cell Line is a CRISPR/Cas9-edited human cell model featuring disruption of the ERAP1 gene in the K562 chronic myelogenous leukemia background. This stable cell line provides a defined loss-of-function system for investigating endoplasmic reticulum aminopeptidase function in antigen processing and immune regulation.

K562 is a Philadelphia chromosome-positive cell line expressing the BCR-ABL fusion tyrosine kinase, widely used as a model for leukemia biology and hematopoietic differentiation. This suspension-adapted cell line is deficient in normal MHC class I expression, making it a suitable platform to study the effects of ERAP1 disruption on peptide loading and immune recognition.

ERAP1 trims N-terminal residues from peptide precursors in the endoplasmic reticulum, optimizing them for loading onto MHC class I molecules. This process, involving interaction with the peptide-loading complex components TAP1, TAP2, and tapasin, shapes the immunopeptidome presented on the cell surface. ERAP1 also catalyzes ectodomain shedding of cytokine receptors such as TNFR1, IL6R, and IL1R2, which modulates inflammatory signals. The enzyme??s expression is regulated by upstream cytokines including IFNG and TNF, and transcription factor NFKB1 influences its induction during stress responses. Knockout of ERAP1 thus disrupts both the generation of optimal MHC class I ligands and the shedding of key immune receptors.

In K562 cells, which lack normal MHC class I expression, ERAP1 knockout further reshapes the residual peptide repertoire, potentially altering natural killer cell recognition through changes in class I?Cpeptide complexes. The BCR-ABL-driven oncogenic context makes this model valuable for examining how aminopeptidase activity intersects with leukemogenesis and immune evasion. Additionally, the reduced shedding of cytokine receptors may impact autocrine and paracrine signaling pathways known to influence K562 proliferation and differentiation.

This knockout cell line supports detailed immunopeptidomic profiling using mass spectrometry, enabling comparison of peptide length distributions and anchor residue preferences in the absence of ERAP1. Functional studies can employ flow cytometry to quantify surface MHC class I levels, while ELISAs detect changes in soluble cytokine receptors. T cell activation assays and NK cell cytotoxicity experiments provide readouts of altered immune recognition. The model is applicable to investigations of autoimmunity, cancer immunotherapy target validation, and the molecular basis of ankylosing spondylitis. Researchers may use RT-qPCR or western blotting to confirm gene disruption. For technical inquiries and ordering details, please contact Ascent Research.