CEBPD Knockout 3D4/21 Cell Line

The CEBPD Knockout 3D4/21 Cell Line is a CRISPR/Cas9-edited knockout cell line generated from the 3D4/21 porcine alveolar macrophage cell line (Sus scrofa). This product achieves targeted disruption of the CEBPD gene, which encodes the C/EBP?? transcription factor, thereby providing a loss-of-function model for studying C/EBP??-dependent regulatory networks in innate immune cells. The cell line retains the immortalized yet physiologically responsive characteristics of the parental 3D4/21 line, ensuring biological relevance in pulmonary immunology research.

The 3D4/21 host cell line was originally established from porcine alveolar macrophages, which are resident immune cells of the lung responsible for first-line defense against inhaled pathogens. These macrophages perform critical functions in pulmonary phagocytosis, antigen presentation, and the production of pro-inflammatory cytokines and lipid mediators. As a widely adopted model for swine respiratory immunity, 3D4/21 cells recapitulate key aspects of alveolar macrophage biology, including responsiveness to bacterial lipopolysaccharide (LPS) and cytokines. This background makes the knockout line particularly valuable for exploring macrophage-driven inflammatory processes and host-pathogen interactions.

At the molecular level, C/EBP?? functions as a central transcriptional regulator activated by upstream signals such as LPS, IL-6, TNF-??, IL-1??, and glucocorticoids. Upon stimulation, C/EBP?? dimerizes with other C/EBP family members, including C/EBP?? and C/EBP??, and engages in cooperative interactions with NF-??B, AP-1, and ATF4 to modulate gene expression. It directly promotes the transcription of downstream targets like IL-8, G-CSF, COX-2, p21, and SAA3, thereby governing inflammatory mediator secretion, cell cycle arrest, and apoptotic signaling. The CEBPD knockout disrupts these transcriptional programs, abolishing C/EBP??-mediated regulation of the acute phase response, Toll-like receptor signaling, and macrophage differentiation pathways.

In the macrophage context, loss of CEBPD function profoundly impairs the cells?? ability to mount normal inflammatory responses. The knockout model allows researchers to dissect the specific contributions of C/EBP?? to cytokine production, phagocytic activity, and stress-induced apoptosis without confounding effects from related transcription factors. This is particularly relevant for studying porcine respiratory diseases such as swine influenza and Actinobacillus pleuropneumoniae infection, where alveolar macrophages play a pivotal role. Additionally, the cell line serves as a platform for examining cross-talk between IL-6/STAT3 and NF-??B pathways that converge on C/EBP??-dependent gene expression.

Typical applications encompass a broad range of functional genomics and drug discovery investigations. Researchers employ this knockout cell line for mechanistic studies of macrophage inflammatory signaling, often using RT-qPCR, western blotting, ELISA-based cytokine profiling, and flow cytometry to assess surface marker expression. RNA-seq and reporter gene assays facilitate genome-wide analysis of C/EBP??-regulated networks, while phagocytosis assays enable direct evaluation of innate immune function. The model is also suitable for screening anti-inflammatory compounds and exploring the roles of C/EBP?? in metabolic syndrome and cancer. For further information, including pricing and availability, please contact Ascent Research.