CD137 CRISPR Activation Plasmid (m): sc-423447-ACT

Mouse Tnfrsf9 encodes CD137 (4-1BB), an inducible TNF receptor superfamily costimulatory molecule expressed on activated T cells and other immune subsets. CD137 engagement promotes survival, proliferation, and effector differentiation through TRAF-dependent signaling that activates NF-κB and MAPK pathways, shaping cytokine production and cytotoxic responses. This axis contributes to regulation of immune homeostasis, inflammatory signaling, and anti-viral and anti-tumor immunity, and is frequently studied in models of autoimmunity, infection, and tumor immunology. Dysregulated CD137 signaling can alter T cell exhaustion, memory formation, and myeloid–lymphoid crosstalk, making Tnfrsf9 a valuable node for mechanistic studies of immune modulation.

CD137 CRISPR Activation Plasmid (m) provides a targeted, non-destructive approach to upregulating endogenous Tnfrsf9 expression without altering the underlying DNA sequence.

CD137 CRISPR Activation Plasmid (m) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the Tnfrsf9 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 Tnfrsf9 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous CD137 expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native Tnfrsf9 locus and enabling the study of CD137-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of CD137 pathway restoration in tumor cells with silenced or reduced Tnfrsf9 expression.

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