B7RP-1 CRISPR Activation Plasmid (m): sc-424469-ACT

Mouse Icosl encodes the co-stimulatory ligand B7RP-1 (ICOSL/CD275), an Ig superfamily member expressed on antigen-presenting cells and some non-hematopoietic stromal compartments. Engagement of ICOS on activated T cells promotes PI3K-dependent signaling that supports T follicular helper differentiation, germinal center reactions, and class-switched antibody production, linking ICOSL to regulation of adaptive immune polarization. ICOSL-mediated communication also influences cytokine networks that shape Th1/Th2/Th17 balance and immune cell trafficking within lymphoid tissues. Dysregulated ICOS–ICOSL signaling is frequently studied in models of autoimmunity, chronic inflammation, allergy, and tumor-associated immune modulation, where altered co-stimulation can shift humoral and cellular immune outputs.

B7RP-1 CRISPR Activation Plasmid (m) provides a targeted, non-destructive approach to upregulating endogenous Icosl expression without altering the underlying DNA sequence.

B7RP-1 CRISPR Activation Plasmid (m) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the Icosl 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 Icosl transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous B7RP-1 expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native Icosl locus and enabling the study of B7RP-1-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of B7RP-1 pathway restoration in tumor cells with silenced or reduced Icosl expression.

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