The HERC4 Knockout A-549 Polyclonal Cells consist of a population of human A-549 lung adenocarcinoma epithelial cells with CRISPR/Cas9-mediated disruption of the HERC4 gene. This polyclonal pool contains a heterogeneous mixture of gene-edited cells, providing a reliable loss-of-function model without clonal artifacts. The cells enable robust studies of HERC4??s role in innate immune signaling and cancer.
A-549 cells are an adherent epithelial line derived from a 58-year-old Caucasian male with lung adenocarcinoma. They exhibit a hypotriploid karyotype and features of alveolar type II pneumocytes, including surfactant protein A expression. Widely used in lung cancer biology, drug testing, and respiratory virus research, these cells are susceptible to pathogens such as influenza A virus and serve as a standard model for assessing cellular responses to infection and therapeutics.
HERC4 is an E3 ubiquitin ligase that catalyzes K48-linked ubiquitination of IRF3, targeting it for proteasomal degradation. Induced downstream of viral RNA sensors RIG-I, MDA5, and adaptor MAVS, HERC4 negatively regulates type I interferon production by promoting IRF3 turnover. This feedback mechanism limits expression of antiviral genes such as IFNB1 and ISG15. HERC4 may also influence NF-??B signaling, connecting it to broader inflammatory pathways.
In A-549 cells, HERC4 knockout removes a critical brake on the interferon response, allowing dissection of enhanced innate immunity in a lung epithelial context. This model is particularly valuable for investigating host?Cvirus interactions, as it permits analysis of unchecked IRF3 activation and subsequent ISG expression during respiratory infections. Furthermore, it offers insight into the intersection of oncogenic signaling and innate immunity in lung adenocarcinoma, where dysregulated ubiquitination can impact tumor cell fate.
Applications include Western blotting for IRF3 and ubiquitin, RT-qPCR for IFNB1 and ISG15, viral plaque assays, and co-immunoprecipitation of HERC4 interactors. The polyclonal knockout cells are also suited for NF-??B reporter assays, flow-based viral antigen detection, and RNA-seq to map transcriptional changes. These cells facilitate drug target validation, mechanistic studies of ubiquitin-dependent immunity, and screening of innate immune modulators. For further information, please contact Ascent Research.
