CD35 CRISPR Activation Plasmid (h): sc-401210-ACT

Complement receptor 1 (CR1), also known as CD35, is a cell-surface glycoprotein expressed on erythrocytes, leukocytes, and follicular dendritic cells that binds complement opsonins C3b and C4b to promote immune complex clearance and regulate complement cascade amplification. By accelerating decay of C3/C5 convertases and acting as a cofactor for factor I–mediated cleavage of C3b/C4b, CD35 shapes innate immune signaling, phagocytosis, and antigen handling during inflammatory responses. CR1 function intersects with classical and alternative complement pathways, influencing host defense, immune complex trafficking, and crosstalk with Fc receptor–mediated processes. Genetic and expression variation in CR1 has been associated with altered susceptibility and pathobiology in immune complex–driven inflammation and complement-linked neuroinflammatory and hematologic phenotypes, supporting its utility as a mechanistic research target.

CD35 CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous CR1 expression without altering the underlying DNA sequence.

CD35 CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the CR1 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 CR1 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous CD35 expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native CR1 locus and enabling the study of CD35-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of CD35 pathway restoration in tumor cells with silenced or reduced CR1 expression.

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