The CASP8 Knockout HAP1 Polyclonal Cells provide a CRISPR/Cas9-edited polyclonal knockout cell population, enabling loss-of-function analysis of CASP8 in a human hematopoietic background. This product consists of a heterogeneous pool of HAP1 cells carrying disruptions in the CASP8 gene introduced via CRISPR/Cas9-mediated gene disruption, eliminating the need for single-clone isolation and offering a robust model for studying CASP8-dependent cellular processes.
The host cell line HAP1 is a near-haploid human cell line derived from the chronic myeloid leukemia cell line KBM-7, retaining essential hematopoietic features. Its near-haploid genome simplifies genetic screening and functional genomics applications, making it an advantageous platform for knockout studies. HAP1 cells express key components of hematopoietic signaling pathways and are widely employed in drug discovery, cell death research, and immunomodulation studies.
CASP8 encodes an initiator caspase that is indispensable for the extrinsic apoptotic pathway. Upon stimulation by death ligands such as FASL, TRAIL, or TNF, CASP8 is recruited to death receptors (e.g., FAS, TNFRSF10A, TNFRSF10B) via the adaptor protein FADD, forming the death-inducing signaling complex (DISC). Activated CASP8 cleaves and activates executioner caspases (CASP3, CASP7) and the pro-apoptotic BCL-2 family member BID, triggering mitochondrial outer membrane permeabilization and apoptosis. Beyond apoptosis, CASP8 functions as a critical regulator of necroptosis by modulating the kinase activities of RIPK1 and RIPK3, and it participates in inflammatory signaling through the NF-kB pathway. CASP8 interacts with multiple regulatory factors, including cFLIP (CFLAR), TRADD, XIAP, and members of the BCL-2 family. Its activity is tightly controlled by the decoy inhibitor FLIP and inhibitor of apoptosis proteins (IAPs) to determine cell fate decisions.
Disruption of CASP8 in the HAP1 hematopoietic model provides a physiologically relevant context to dissect death receptor signaling and cross-talk between apoptotic and necroptotic pathways. The leukemia-derived background retains molecular machinery for both extrinsic apoptosis and regulated necrosis, making this knockout model suitable for delineating CASP8-dependent and -independent cell death modalities. Researchers can utilize these cells to investigate how loss of CASP8 sensitizes cells to necroptosis induced by RIPK1/RIPK3 activation, or how it alters NF-kB-dependent transcriptional responses. This model is particularly valuable for exploring the molecular underpinnings of autoimmune lymphoproliferative syndrome, immunodeficiency, cancer, and neurodegenerative diseases where CASP8 dysregulation is implicated.
Typical applications include mechanistic studies of apoptosis and necroptosis, death receptor signaling analysis, screening of pro-apoptotic or necroptotic compounds, and evaluation of immunomodulatory agents. The polyclonal knockout population is well-suited for downstream assays such as caspase activity measurements (e.g., colorimetric or fluorogenic substrates), Annexin V/propidium iodide flow cytometry, Western blotting for caspase cleavage and RIPK1 phosphorylation, co-immunoprecipitation to assess DISC or necrosome assembly, RT-qPCR for NF-kB target gene expression, and cell viability assays under various death stimuli. For further technical details and ordering information, please contact Ascent Research.
