CpG ODNs have immunostimulatory effects similar to bacterial DNA and can activate both innate and adaptive immune responses. Based on their structure and immunoreactivity, CpG ODNs can be categorized into type A, type B, and type C. Different types of CpG ODNs have different structural features, functions, and applications.

Class A CpG ODNs are characterized by a phosphodiester (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.

Application:Antitumor and antiviral immune adjuvants for the treatment of immunodeficiency diseases.

Class B CpG ODNs are linear and fully modified with phosphorothioates. They possess strong immunostimulatory activity on B cells but fail to activate plasmocytoid dendritic cells.

Application: Vaccine adjuvants for subunit vaccines, DNA vaccines, etc.

Class C CpG ODNs combine features of both class A and B, making them highly versatile as they activate both plasmocytoid dendritic cells and B cells.

Application:Autoimmune disease stimulants.

1. Role of CpG ODNs in vaccines against infectious agents

Utilizing CpG ODNs as an immune adjuvant for human vaccine production can improve the body's immunity against pathogenic substances and introduce anti-tumor effects, and is superior to commonly used adjuvants in terms of storage, cost, and slow release.

Some research has shown that CpG ODNs have a good immune adjuvant effect against bacterial infections in pigs. In avian disease control, some experiments have confirmed that CpG ODNs can enhance the immune activity of the ALV-J subunit vaccine.However, other types of veterinary vaccine adjuvants are still being researched,so their market prospects are very promising.

2. Role of CpG ODNs in vaccines against allergens

Osinophilia and increased serum IgE levels are indicators of allergic inflammation. Th1 cell-secreted Th1-type cytokines (e.g., IFN-γ) inhibit Th2 cell-mediated eosinophilia. Th1 and Th2 cells with the same antigen specificity inhibit each other. In animal models, CpG ODNs in combination with drugs or vaccines can cause a Th1 response to allergens and induct of allergic inflammation. It was found that CpG ODNs binding to pollen allergens (TOLAMBA) reduces the response of nasal mucosal immune cells to allergen stimulation, shifting from a Th2 to a Th1 response, and can be used to treat pollen allergy.

3. Role of CpG ODNs in Tumor Vaccines

CpG ODNs are relatively safe as a stand-alone treatment. However, the size of the induced immune response is not sufficient enough to eliminate tumors.

Vaccines, alone, usually fail to elicit a strong immune response. Therefore, many clinical trials have tested peptide-chain vaccines that combine CpG ODNs with a variety of tumor-associated antigens (TAAs) - with the most commonly used antigen being K-type CpG ODN7909.

Research has shown that when T cells stimulated with a vaccine containing CpG 7909, the T cells will produce 2-fold to 10-fold more cytokines TNF-alpha, IL-2, and CD107a after re-stimulation with vaccine-derived peptidesin vitro compared to the CpG ODNs-free vaccine group.

In recent years, the use of CpG ODNs as immune adjuvants have received widespread attention, with more than 20 types of CpG ODN-adjuvanted vaccines entering clinical studies.

At Synbio Technologies, we proudly offer a comprehensive range of CpG ODNs (A, B, and C) to researchers around the world. Our customized synthesis approach ensures that each CpG ODN meets the precise specifications of our customers, enabling us to help facilitate advancements in both preventive and therapeutic vaccine research.