CD22 CRISPR Activation Plasmid (m): sc-419539-ACT

Mouse Cd22 encodes CD22, a B cell–restricted sialic acid–binding Ig-like lectin that functions as an inhibitory co-receptor for the B cell antigen receptor (BCR). Through its cytoplasmic ITIM motifs, CD22 recruits phosphatases such as SHP-1 to dampen proximal BCR signaling, shaping calcium flux, MAPK activity, and downstream transcriptional programs that govern activation thresholds and tolerance. CD22 also contributes to B cell adhesion and trafficking by recognizing α2,6-linked sialylated glycans, influencing interactions within lymphoid microenvironments. Dysregulated CD22 signaling and expression are linked to altered humoral responses and immune tolerance phenotypes, supporting its relevance in studies of B cell dysregulation and autoimmunity-associated mechanisms.

CD22 CRISPR Activation Plasmid (m) provides a targeted, non-destructive approach to upregulating endogenous Cd22 expression without altering the underlying DNA sequence.

CD22 CRISPR Activation Plasmid (m) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the Cd22 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 Cd22 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous CD22 expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native Cd22 locus and enabling the study of CD22-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of CD22 pathway restoration in tumor cells with silenced or reduced Cd22 expression.

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