CIITA CRISPR Activation Plasmid (h): sc-401762-ACT

Human CIITA (class II major histocompatibility complex transactivator) is a master transcriptional regulator that coordinates inducible expression of MHC class II genes and associated antigen processing components. Acting downstream of cytokine and innate immune cues, including interferon-driven signaling, CIITA integrates transcriptional programs controlling antigen presentation, adaptive immune priming, and cell-type–specific immune responsiveness. Dysregulated CIITA activity alters immune surveillance and inflammatory signaling, with relevance to antigen-presentation defects, autoimmunity-associated gene expression patterns, and tumor immune evasion mechanisms. As a non–DNA-binding coactivator that assembles enhanceosome complexes at MHC II promoters, CIITA is widely used to probe transcriptional control of HLA loci and immune phenotype remodeling in diverse cell models.

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

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

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