The C1S Knockout A-549 Polyclonal Cells are a CRISPR/Cas9-mediated polyclonal knockout cell population derived from the A-549 human lung epithelial cell line, designed to ablate expression of the C1S gene. This product provides a reliable loss-of-function model for dissecting the classical complement pathway in a lung adenocarcinoma background. The polyclonal format offers a heterogeneous pool of edited cells, facilitating pooled functional analyses and minimizing clonal variation artifacts. Permanent gene disruption is achieved via targeted CRISPR/Cas9 editing, ensuring stable knockout and enabling long-term studies of complement-dependent mechanisms.
The host A-549 cell line was established from a lung adenocarcinoma explant of a 58-year-old Caucasian male and is widely employed as a model of alveolar type II epithelial cells. These cells retain key features of pulmonary epithelia, including surfactant production and expression of innate immune mediators, and are extensively used in lung cancer research, drug metabolism studies, and investigations of respiratory physiology. The A-549 background provides a clinically relevant context for examining the interplay between complement activation and malignant or inflammatory lung diseases.
C1S encodes complement component 1s, a serum serine protease that is critical for initiation of the classical complement cascade. Within the C1 complex, C1S is activated by C1r upon C1q binding to immune complexes and thereafter cleaves C4 and C2 to generate the C3 convertase (C4b2a). This reaction is regulated by C1-inhibitor (SERPING1). Downstream, C3 convertase mediates C3 cleavage, leading to C5 convertase assembly and membrane attack complex (MAC) formation. Thus, C1S knockout prevents cascade progression beyond the recognition phase, blocking opsonization, inflammation, and cytolysis.
In lung epithelial cells, complement components are known to contribute to local immune surveillance and tissue homeostasis, but their dysregulation is implicated in tumor immune evasion and chronic inflammation. By eliminating C1S function in A-549 cells, this knockout model enables researchers to selectively interrogate classical complement pathway contributions to lung adenocarcinoma cell biology, including complement-mediated cell signaling, modulation of the tumor microenvironment, and resistance to complement-dependent cytotoxicity. This tool is valuable for distinguishing complement-dependent from complement-independent functions of C1S in pulmonary epithelial pathophysiology.
This polyclonal knockout product supports a variety of research applications, including western blotting and RT-qPCR for target validation, complement activation assays measuring C4 cleavage, flow cytometry for complement deposition, cytokine secretion profiling, and RNA-seq transcriptional analysis. It is especially useful for drug testing of complement-targeted therapies, modeling complement deficiency in lung cancer, and probing immune evasion mechanisms. For further information or technical support, contact Ascent Research.
