CpG oligodeoxynucleotides (or CpG ODN)  DNA molecules that contain an unmethylated CG (Cytosine-guanine) di nucleotide in a specific base sequence (CpG motifs). The p refers to the phosphodiester backbone. CpG oligodeoxynucleotides (ODNs) represent a novel pharmacotherapeutic class with profound immunomodulatory properties. These CpG motifs are not seen in eukaryotic DNA, in which CG dinucleotides are suppressed and, when present, usually methylated, due to this they are considered pathogen-associated molecular patterns (PAMPs). The CpG PAMP is recognized by the pattern recognition receptor (PRR) Toll-Like Receptor 9 (TLR9), which is constitutively expressed only in B cells and plasmacytoid dendritic cells (pDCs) in humans and other higher primates. Unmethylated CpG ODNs (18-24 bp in length) possess immunomodulatory properties similar to bacterial DNA and they act as immuno stimulants. The immunostimulatory properties of CpGs include induction of a Th1-type response with prominent release of IFN-&alpha, IL-12, and IL-18.

Synthetic CpG have a partially or completely phosphorothioated backbone instead of the typical phosphodiester backbone and a poly G tail at the 3' end, 5' end, or both. Numerous sequences have been shown to stimulate TLR9 with variations in the number and location of CpG dimers, as well as the precise base sequences flanking the CpG dimers. CpG ODNs are classified into 5 classes, based on their sequence, secondary structures, and effect on human peripheral blood mononuclear cells (PBMCs). The five classes are Class A (Type D), Class B (Type K), Class C, Class P, and Class S Three major classes of immunostimulatory CpG-ODNs are well characterized according to their in vitro activities and chemical compositions. Class A stimulate the production of large amounts of Type I interferons, the most important one being IFNα, and induce the maturation of pDCs. They are also strong activators of NK cells through indirect cytokine signaling. Class B ODN are strong stimulators of human B cell and monocyte maturation. They stimulate the maturation of pDC to a lesser extent than Class A ODN and very small amounts of IFNα. Class C ODN combine features of both types A and B. They contain a complete phosphorothioate backbone and a CpG-containing palindromic motif. They induce strong IFN-α production from pDC and B cell stimulation.

Several groups have studied the sequence requirements, specificity, signaling pathways and kinetics of the TLR (Toll-like receptor) 9 suppression by 'inhibitory DNA motifs', which led to a revised classification of inhibitory ODNs. Class I: G-stretch ODNs: TLR9-specific competitors, some iODNs may also affect TLR7 and TLR8 signaling. Class II: ODNs with telomeric repeats: TLR-independent inhibitors of STAT signaling (cellular uptake via an "ODN receptor"?) Class III: Inhibitors of DNA uptake in a sequence independent manner Class IV: Long phosphorothioate ODNs as direct competitors of TLR9 signaling in a sequence independent manner.

Product ordering Information (Data sheets and Prices are posted at the website)

CpG oligodeoxynucleotides (or CpG ODNs) as Vaccine Adjuvant and ELISA kits

Notes: 1. Bases in capital are phosphodiester and those in lower case are phosphorothioate. Palindromic sequences are underlined. 2. Bases depicted in italics show AT-ODN sequence. 3. Negative control contains GpC nucleotides instead of CpG. 4. Contact ADI to place a special order for Biotin or FITC Conjugates.

ELISA Kits for the study of Adjuvant effect on antibody response

The main function of adjuvants (conventional oil-based, special formulation or ODNs) is to enhance antibody response to a given antigen. The antibody levels or titer in the host species (mouse, rat, rabbit, G. pig, Ferret, Hamster, monkey or human etc) is typically measure by ELISA. ADI provides several species specific ELISA kits to measure antibody titer. These kits contain all necessary reagents, except user's specific antigen, for about 1000 tests. Please contact us for details.

We also have ELISA kit for IgG, IgM, IgA, IgE or individual IgG isotypes (IgG1, 2a, 2b, IgG3) in serum or plasma for mouse, rat, human etc

ELISA Kits for the study of Adjuvant effect on anbtibody response using model antigens

Several model proteins have been used as model antigens (Bovine serum albumin/BSA or HSA, ovalbumin or OVA, Keyhole limpet hemocyanins/KLH, thyroglobulin, DNP-KLH/Albumin or Tetanus Toxoid or TTX or Diptheria Toxoids. Adjuvants (conventional or ODN-based) have been used to study antibody response to a model antigen in a given species of host. We have specific antibody ELISA kits for these model antigens.

ELISA Kits to measure ODN-induced anti-dsDNA or anti-ssDNA anbtibody

It is possible that some DNA-sequences (ODNs) when used as adjuvant may invoke anti-DNA antibodies. The presence of absence of anti-DNA antibodies must be investigated if any ODNs is intended for vaccines.