TARC CRISPR Activation Plasmid (h): sc-401905-ACT

CCL17 encodes thymus and activation-regulated chemokine (TARC), a secreted CC chemokine that promotes directed migration of CCR4-expressing T cells, including Th2-polarized subsets, to sites of inflammation. By shaping leukocyte trafficking and dendritic cell–T cell communication, TARC contributes to immune cell positioning within tissues and coordination of cytokine-driven responses in the chemokine signaling network. Dysregulated CCL17/TARC expression is frequently studied in allergic inflammation and other immune-mediated pathologies where altered chemotactic gradients influence immune infiltration and tissue remodeling. In human model systems, CCL17 serves as a tractable readout for inflammatory circuit activation and a node for interrogating chemokine–receptor axis behavior.

TARC CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous CCL17 expression without altering the underlying DNA sequence.

TARC CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the CCL17 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 CCL17 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous TARC expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native CCL17 locus and enabling the study of TARC-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of TARC pathway restoration in tumor cells with silenced or reduced CCL17 expression.

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