TLR9 agonists

Toll-like receptor 9 (TLR9) is critical for distinguishing foreign from mammalian DNA during the early innate immune response. The receptor is localized in the endosomal compartment and recognizes the unmethylated CpG-containing motifs of bacterial and viral DNA. Upon recognition, MYD88 (myeloid differentiation primary response 88) is recruited to the receptor and the TLR9 pathway is activated. The signaling cascade finally leads to the activation of the transcription factors NF-κB, AP-1, and/or IRF-7. Thus, the expression of pro-inflammatory cytokines and type I IFNs is triggered, which initiates the immune response.  

TLR9 is mainly expressed in antigen-presenting cells, such as B cells or dendritic cells (DCs), and activation of the pathway leads to the maturation of the respective cell. Besides its functions for detecting infections, TLR9 signaling appears to play a role in cancer, tissue damage, and several autoimmune diseases.  

Synthetic oligodesoxynucleotides (ODNs) containing CpG motifs (CpG ODNs) can mimic the immune stimulatory effect of naturally occurring ligands, functioning as TLR9 agonists. We provide high-quality CpG ODNs for activating immune cells and the respective controls. Control compounds for CpG ODNs share the sequence with their stimulatory counterparts but contain GpC dinucleotides instead of the CpG motifs. Thus, the CpG-specificity of the stimulatory effect can be shown, when using CpG ODNs and the respective controls.