Why would CpG DNA work as an adjuvant and what type of immune response would it be most likely to induce?
The adjuvant effect of CpG ODNs is mediated through improved function of professional antigen-presenting cells and the resultant generation of humoral and cellular vaccine-specific immune responses. CpG ODNs increase the magnitude and accelerate the development of vaccine-induced responses.
What is an ODN sequence?
CpG ODNs are short synthetic single-stranded DNA molecules containing unmethylated CpG dinucleotides in particular sequence contexts (CpG motifs). CpG ODNs possess a partially or completely phosphorothioated (PS) backbone, as opposed to the natural phosphodiester (PO) backbone found in genomic bacterial DNA.
How many CpG sites are in genome?
28 million CpG sites
The 28 million CpG sites in the human genome are predominantly methylated and occur at low frequencies (on average 1/100 bp) across the genome (16,23). Strong interest has however been drawn by the methylation patterns of comparably dense regions of CpG sites.
What are CpG islands in genetics?
CpG islands (CGIs) are regions of the genome that contain a large number of CpG dinucleotide repeats. In mammalian genomes, CpG islands usually extend for 300–3000 base pairs. They are located within and close to sites of about 40% of mammalian gene promoters.
What is the significance of CpG islands?
CpG islands are useful markers for genes in organisms containing 5-methylcytosine in their genomes. In addition, CpG islands located in the promoter regions of genes can play important roles in gene silencing during processes such as X-chromosome inactivation, imprinting, and silencing of intragenomic parasites.
What does DNA methylation indicate?
DNA methylation regulates gene expression by recruiting proteins involved in gene repression or by inhibiting the binding of transcription factor(s) to DNA. During development, the pattern of DNA methylation in the genome changes as a result of a dynamic process involving both de novo DNA methylation and demethylation.
What is a CpG ODN?
CpG ODNs are short synthetic single-stranded DNA molecules containing unmethylated CpG dinucleotides in particular sequence contexts (CpG motifs). CpG ODNs possess a partially or completely phosphorothioated (PS) backbone, as opposed to the natural phosphodiester (PO) backbone found in genomic bacterial DNA .
What are CpG-a Class A and Type B odns?
These three classes are Class A (Type D), Class B (Type K) and Class C: CpG-A ODNs are characterized by a PO central CpG-containing palindromic motif and a PS-modified 3’ poly-G string. They induce high IFN-α production from pDCs but are weak stimulators of TLR9-dependent NF-κB signaling and pro-inflammatory cytokine (e.g. IL-6) production.
How do CpG-B odns induce IFN-α production?
They induce high IFN-α production from pDCs but are weak stimulators of TLR9-dependent NF-κB signaling and pro-inflammatory cytokine (e.g. IL-6) production. CpG-B ODNs contain a full PS backbone with one or more CpG dinucleotides.
Do CpG odns activate B cells from murine splenocytes?
Human PBMCs were incubated with CpG ODNs or their controls at a final concentration of 1.6µg/ml for 24 hours then labeled with CD19, CD80, and CD86 mAbs, for analysis of B cell activation by flow cytometry. The effect of ODNs on the activation of B cells derived from murine splenocytes