BLCAM CRISPR Activation Plasmid (h): sc-401451-ACT

CD22 (BLCAM) is a B cell–restricted sialic acid–binding immunoglobulin-like lectin that functions as an inhibitory coreceptor of the B cell receptor (BCR), tuning antigen-driven signaling thresholds. Through immunoreceptor tyrosine-based inhibitory motifs (ITIMs), it recruits phosphatases such as SHP-1/SHIP to modulate proximal kinase activity and downstream pathways including PI3K/AKT, MAPK, and calcium flux, thereby shaping B cell activation, survival, and tolerance. CD22 also contributes to B cell adhesion and trafficking via glycan-dependent interactions at the cell surface. Dysregulated CD22 expression or signaling has been associated with altered immune homeostasis and is frequently studied in the context of B cell malignancies and autoimmunity-relevant B cell phenotypes.

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

CD22 CRISPR Activation Plasmid (h) 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.