BLC CRISPR Activation Plasmid (m): sc-424962-ACT

Cxcl13 encodes the chemokine BLC (B lymphocyte chemoattractant), a key organizer of B cell trafficking and follicle architecture in secondary lymphoid tissues. BLC signals primarily through CXCR5 to guide chemotaxis of B cells and T follicular helper cells, supporting germinal center formation, affinity maturation, and coordinated humoral immune responses. This axis integrates with inflammatory chemokine networks, stromal cell–immune cell crosstalk, and lymphoid neogenesis programs that reshape tissue microenvironments during chronic inflammation. Dysregulated CXCL13 expression is widely used as a biomarker and mechanistic node in models of autoimmune pathology, ectopic lymphoid structures, and tumor-associated immune organization.

BLC CRISPR Activation Plasmid (m) provides a targeted, non-destructive approach to upregulating endogenous Cxcl13 expression without altering the underlying DNA sequence.

BLC CRISPR Activation Plasmid (m) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the Cxcl13 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 Cxcl13 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous BLC expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native Cxcl13 locus and enabling the study of BLC-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of BLC pathway restoration in tumor cells with silenced or reduced Cxcl13 expression.

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