B7-H3 CRISPR Activation Plasmid (h): sc-402032-ACT

CD276 encodes the immune regulatory glycoprotein B7-H3, a B7 family member broadly implicated in modulation of T cell and NK cell activity at the cell surface. B7-H3 participates in immunoregulatory signaling that shapes cytokine production, antigen-presenting cell interactions, and immune evasion programs within the tumor microenvironment. Elevated B7-H3 expression has been reported across multiple malignancies and is frequently associated with invasive phenotypes, altered inflammatory signaling, and remodeling of stromal–immune crosstalk. These properties make CD276 a useful molecular handle for studying immune checkpoint biology, interferon-associated transcriptional states, and cancer-associated immune suppression.

B7-H3 CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous CD276 expression without altering the underlying DNA sequence.

B7-H3 CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the CD276 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 CD276 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous B7-H3 expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native CD276 locus and enabling the study of B7-H3-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of B7-H3 pathway restoration in tumor cells with silenced or reduced CD276 expression.

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