CD89 CRISPR Activation Plasmid (h): sc-403014-ACT

FCAR encodes CD89 (FcαRI), an immunoglobulin A (IgA) Fc receptor expressed primarily on myeloid cells such as neutrophils, monocytes, macrophages, and eosinophils. CD89 engagement by IgA immune complexes triggers FcR γ-chain–dependent signaling through ITAM phosphorylation, activating SYK, PI3K, MAPK, and downstream inflammatory and antimicrobial effector programs including phagocytosis, degranulation, cytokine release, and antibody-dependent cellular cytotoxicity. By shaping mucosal and systemic IgA-mediated immunity, FCAR influences innate–adaptive crosstalk and immune complex handling. Dysregulated CD89 signaling and altered receptor expression have been linked to inflammatory and autoimmune pathology, including IgA nephropathy and other immune complex–driven diseases, supporting its relevance for mechanistic immunology studies.

CD89 CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous FCAR expression without altering the underlying DNA sequence.

CD89 CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the FCAR 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 FCAR transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous CD89 expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native FCAR locus and enabling the study of CD89-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of CD89 pathway restoration in tumor cells with silenced or reduced FCAR expression.

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