CD74 CRISPR Activation Plasmid (h): sc-400279-ACT

Human CD74 encodes the invariant chain (Ii), a type II transmembrane protein that chaperones MHC class II α/β heterodimers in the endoplasmic reticulum, regulates their trafficking through endosomal compartments, and is proteolytically processed to generate CLIP for peptide loading. By controlling antigen processing and presentation, CD74 influences adaptive immune activation and antigen-specific T cell priming, and it also participates in intracellular signaling in antigen-presenting cells through interactions with surface receptors such as macrophage migration inhibitory factor (MIF). CD74 expression is prominent in B cells, dendritic cells, and other professional antigen-presenting cells, linking it to pathways governing endolysosomal proteostasis, immune surveillance, and inflammatory responses. Dysregulated CD74 has been associated with immune-mediated pathology and is frequently studied in hematologic malignancy and tumor microenvironment contexts where antigen presentation and immune signaling are perturbed.

CD74 CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous CD74 expression without altering the underlying DNA sequence.

CD74 CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the CD74 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 CD74 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous CD74 expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native CD74 locus and enabling the study of CD74-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of CD74 pathway restoration in tumor cells with silenced or reduced CD74 expression.

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