CD3-δ CRISPR Activation Plasmid (h): sc-401519-ACT

CD3D encodes CD3-δ, a core component of the T cell receptor (TCR)–CD3 complex required for antigen-dependent T cell activation and signal propagation. CD3-δ participates in assembly and surface expression of the TCR complex and transduces signals through its cytoplasmic ITAM motif, engaging LCK/ZAP70 and downstream pathways such as LAT/SLP-76, PLCγ1–NFAT, NF-κB, and MAPK/ERK to coordinate proliferation and cytokine programs. Altered CD3D expression or function can disrupt thymocyte development, TCR signaling competence, and immune homeostasis, making it relevant to studies of immunodeficiency, immune dysregulation, and tumor-immune interactions. As a lineage-defining T cell marker, CD3-δ is also widely used to model receptor signaling thresholds and activation states in human immune cells.

CD3-δ CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous CD3D expression without altering the underlying DNA sequence.

CD3-δ CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the CD3D 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 CD3D transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous CD3-δ expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native CD3D locus and enabling the study of CD3-δ-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of CD3-δ pathway restoration in tumor cells with silenced or reduced CD3D expression.

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