HLA-DRα CRISPR Activation Plasmid (h): sc-401010-ACT

HLA-DRA encodes the HLA-DRα chain, an essential component of MHC class II heterodimers that present exogenous peptide antigens to CD4+ T cells and coordinate adaptive immune activation. HLA-DRα participates in antigen processing and presentation pathways, including invariant chain–dependent trafficking through endosomal compartments and peptide loading regulated by HLA-DM, shaping T cell selection and peripheral immune responses. Variation in MHC class II expression or regulation is closely linked to immune dysregulation and inflammatory pathology, with strong relevance to autoimmunity and transplant immunobiology. Altered HLA-DR expression is also widely used as a marker of myeloid and B cell activation states, informing studies of immune cell differentiation and responses to cytokine signaling.

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

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

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