The C1QA Knockout HeLa Polyclonal Cells constitute a CRISPR/Cas9-edited polyclonal knockout population derived from HeLa cells, in which the C1QA gene encoding the complement C1q A chain has been disrupted. This loss?of?function model eliminates C1q A chain protein expression, thereby preventing the assembly of functional C1q hexamers and abrogating the initiation of the classical complement pathway. The polyclonal nature of the product provides a diverse array of edited alleles, enabling robust assessment of gene function without the biases introduced by single?cell clonal selection.
The host HeLa cell line, originally isolated from a cervical adenocarcinoma and positive for human papillomavirus 18 (HPV?18), is an epithelial cell model widely used in biomedical research. Its well?characterized transcriptome, rapid proliferation, and amenability to genetic manipulation make it a versatile platform for studying cancer biology, virology, and immune mechanisms. In the context of complement research, HeLa cells do not endogenously express complement components, offering a clean background for dissecting post?genetic modification complement?related phenotypes.
The C1QA protein is the A?chain component of C1q, a multimeric recognition molecule that, together with C1QB and C1QC, forms the hexameric C1q complex. C1q associates with the serine proteases C1R and C1S, and upon binding to immune complexes or apoptotic cells via receptors such as calreticulin (CALR) and LRP1 (CD91), activates C1R and C1S. This triggers cleavage of C4 and C2 to form the C3 convertase (C4b2a), which amplifies downstream events including C3 deposition, C5 activation, and membrane attack complex (C5b?9) assembly. Transcription of C1QA is regulated by PU.1 (SPI1), CEBPB, and IRF8, and is induced by pro?inflammatory cytokines such as IFNG and TNF. Knockout of C1QA thus disrupts the entire cascade, impairing opsonization, immune complex clearance, and apoptotic cell removal.
In HeLa cells, ablation of C1QA creates a definitive model that eliminates any residual classical pathway activity, enabling precise dissection of C1q?dependent signaling in a human cancer context. This is particularly valuable for investigating the interplay between complement activation and tumor?cell biology, including complement?dependent cytotoxicity and phagocytic clearance of malignant cells. The model recapitulates features of C1q deficiency diseases, such as systemic lupus erythematosus and recurrent infections, providing a relevant cellular tool for autoimmunity research.
The C1QA Knockout HeLa Polyclonal Cells are suited for a wide array of experimental applications, including mechanistic studies of the classical complement cascade, drug screening for complement inhibitors, and investigation of apoptotic cell phagocytosis. Researchers can validate knockout efficiency via western blotting, RT?qPCR, and C1q?binding ELISA, and assess functional consequences using CH50 hemolytic assays, flow cytometry for C1q deposition, or immunofluorescence microscopy. For further information, please contact Ascent Research.
