NOD2 Knockout A549 Cell Line

The NOD2 Knockout A549 Cell Line is a CRISPR/Cas9-edited human lung adenocarcinoma epithelial cell line carrying a targeted disruption of the NOD2 gene. This engineered loss-of-function model enables precise investigation of NOD2-dependent innate immune signaling, inflammatory responses, and autophagy regulation without interference from endogenous protein expression. Created through CRISPR/Cas9-mediated gene disruption, the cell line provides a consistent and renewable platform for dissecting the molecular mechanisms governed by this intracellular pattern recognition receptor.

Derived from human alveolar basal epithelial adenocarcinoma, the A549 parental cell line is a widely used model of type II alveolar epithelial cells and lung carcinoma. Its adherent epithelial morphology and stable growth characteristics make it well-suited for in vitro studies of pulmonary biology, infectious disease, and cancer. The cells retain key features of alveolar epithelium, including the expression of surfactant proteins and the capacity to activate innate immune pathways upon microbial challenge, thereby offering a physiologically relevant background for examining NOD2 function in the lung.

The NOD2 gene encodes a cytosolic receptor that senses muramyl dipeptide (MDP), a peptidoglycan component of both Gram-positive and Gram-negative bacteria. Upon ligand binding, NOD2 recruits the adaptor kinase RIPK2 through homotypic CARD-CARD interactions, forming a signaling complex that also involves CARD9, SGT1, and HSP90. Activated RIPK2 promotes the assembly of the IKK complex and TAK1, leading to phosphorylation and degradation of I??B??, nuclear translocation of NF-??B, and activation of MAP kinase cascades, including p38 and JNK. These events drive the transcription of pro-inflammatory cytokines such as IL-6, IL-8, and TNF-??, as well as antimicrobial peptides. Additionally, NOD2 interacts with ATG16L1 to initiate autophagy, a process crucial for bacterial clearance and antigen presentation. Upstream regulators of NOD2 signaling include MDP, bacterial peptidoglycan, ER stress, and Toll-like receptor ligands.

In the A549 lung epithelial context, NOD2 knockout provides a valuable tool for exploring the contribution of this receptor to pulmonary innate immunity and inflammatory disease. Although NOD2 is best characterized in intestinal Paneth cells and myeloid cells, its expression in airway epithelial cells implicates it in host defense against respiratory pathogens and in the regulation of inflammatory mediators. Loss of NOD2 function in this cell line can reveal its role in sensing bacterial cell wall components, shaping cytokine profiles, and modulating autophagy in pulmonary tissues. The model also facilitates studies of NOD2??s intersection with oncogenic signaling, given the adenocarcinoma origin of A549 cells, thus offering insights into immunomodulation within the tumor microenvironment.

Typical research applications encompass innate immune sensing, NOD-like receptor pathway dissection, host-pathogen interactions, and drug screening for NOD2-related disorders such as Crohn??s disease, Blau syndrome, early-onset sarcoidosis, and colorectal cancer. Functional assays that can be performed with this knockout cell line include Western blotting for p65 phosphorylation to assess NF-??B activation, RT-qPCR and ELISA for IL-6 and IL-8 expression, immunofluorescence for subcellular NOD2 localization, NF-??B luciferase reporter assays, co-immunoprecipitation to probe NOD2-RIPK2 interaction, bacterial invasion assays, and autophagy flux measurements. For further technical details or inquiries regarding this product, please contact Ascent Research.