The DNASE1 Knockout HAP1 Polyclonal Cells constitute a CRISPR/Cas9-edited polyclonal knockout population derived from the HAP1 human near-haploid cell line, featuring targeted disruption of the DNASE1 gene. This model facilitates loss-of-function analysis of the secreted endonuclease DNASE1, which is essential for extracellular DNA clearance and maintenance of immunological tolerance. The polyclonal composition ensures a diverse pool of knockout cells suitable for pooled functional screens and comparative assays without the constraints of clonal selection.
HAP1 cells are a human near-haploid cell line established from the KBM-7 chronic myeloid leukemia (CML) patient. Their near-haploid karyotype minimizes functional redundancy and streamlines the interpretation of gene knockout phenotypes. Retaining core apoptotic, DNA damage response, and hematopoietic signaling pathways, HAP1 cells provide a relevant cellular backdrop for investigating DNASE1-mediated DNA catabolism and its link to autoimmunity.
The DNASE1 gene encodes a calcium- and magnesium-dependent endonuclease that preferentially hydrolyzes double-stranded DNA, facilitating the dismantling of DNA released during apoptosis and extruded in neutrophil extracellular traps (NETs). Its transcription is induced by glucocorticoid receptor signaling and pro-inflammatory cytokines, while its enzymatic activity is directly inhibited by monomeric G-actin. DNASE1 functions within a nuclease network including caspase-activated DNase (CAD) and endonuclease G to ensure complete chromatin degradation. Loss of DNASE1 activity leads to persistent extracellular DNA, which serves as a source of nuclear autoantigens, driving the production of anti-dsDNA antibodies and contributing to the etiology of systemic lupus erythematosus (SLE) and related nephritis.
The near-haploid nature of the HAP1 host heightens the impact of DNASE1 disruption by eliminating the confounding influence of a second wild-type allele, enabling cleaner phenotypic analysis. This knockout model effectively mimics DNASE1 deficiency, demonstrating impaired serum DNA degradation and enhanced susceptibility to autoimmune pathology. Within the CML-derived context, it also permits investigation of how defective apoptotic cell clearance and NET persistence shape immune activation. Such studies are instrumental for dissecting the molecular mechanisms of lupus nephritis and other systemic autoimmune conditions.
Routine applications encompass apoptosis and NETosis investigations, including TUNEL assays to quantify DNA fragmentation and NET degradation assays to evaluate nuclease-dependent clearance of neutrophil extracellular traps. The cells support DNase activity assays utilizing fluorescent or radiolabeled DNA substrates, anti-dsDNA ELISA for autoantibody detection in co-culture setups, and flow cytometry to assess apoptosis markers. Additionally, the polyclonal knockout pool is well-suited for haploid genetic screens aimed at identifying novel regulators of DNA clearance pathways. For technical specifications and ordering information, please contact Ascent Research.
