IRF3 CRISPR Activation Plasmid (h): sc-417171-ACT

Interferon regulatory factor 3 (IRF3) is a ubiquitously expressed transcription factor that functions as a central hub of innate antiviral immunity. Upon sensing cytosolic DNA or RNA, IRF3 is activated downstream of pattern-recognition receptor pathways including cGAS–STING and RIG-I/MDA5–MAVS, where TBK1/IKKε-mediated phosphorylation promotes IRF3 dimerization, nuclear translocation, and induction of type I interferons and interferon-stimulated genes. IRF3 also interfaces with NF-κB signaling, apoptosis, and inflammatory cytokine programs, shaping cell-intrinsic responses to pathogens and cellular stress. Dysregulated IRF3 activity has been implicated in aberrant interferon signatures observed across infectious disease models, autoinflammatory phenotypes, and tumor-immune interactions, making it a key node for mechanistic studies of immune regulation.

IRF3 CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous IRF3 expression without altering the underlying DNA sequence.

IRF3 CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the IRF3 locus in human cell lines. The system is built around a catalytically inactive Cas9 (dCas9) carrying two inactivating mutations (D10A and N863A) that eliminate nuclease activity while preserving DNA binding. This dCas9 is fused to VP64, a potent transcriptional activator, and is co-expressed with a blasticidin resistance gene for selection. The second plasmid encodes the MS2-p65-HSF1 fusion protein, a secondary activator complex that works in concert with dCas9-VP64, alongside a hygromycin resistance gene. The third plasmid encodes a target-specific 20 nt sgRNA fused to two MS2 RNA aptamers that recruit the MS2-p65-HSF1 complex to the activation site, accompanied by a puromycin resistance gene. The three plasmids are delivered at a 1:1:1 mass ratio for balanced expression of all system components.

Once assembled at the target locus, the SAM complex binds within approximately 200 bp upstream of the IRF3 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous IRF3 expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native IRF3 locus and enabling the study of IRF3-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of IRF3 pathway restoration in tumor cells with silenced or reduced IRF3 expression.

For Research Use Only. Not Intended for Diagnostic or Therapeutic Use.