Tumor-Associated GM2 Ganglioside Antigen Production Service at CD BioGlyco

We provide a chemical synthesis method that possesses flexibility in functionalizing the antigen for immunological investigations.

Antigen Production

To synthesize GM2 tetrasaccharide 1, which has a reducing end-free amine, we first perform regioselective sialylation of the lactosyl diol acceptor 2 using sialyl donor 3. This is followed by glycosylation of the 4’-OH with galactosamine (GalN) donor 4.

Fig.2 Retrosynthetic analysis of GM2 tetrasaccharide 1. (CD BioGlyco)

• Our synthesis begins with lactoside 5, derived from d-lactose, which is then transformed into diol 2 through protecting group manipulations.
• Sialylation of acceptor 2 is performed with thiosialoside donor 3. The initial coupling of 2 and 3 is mediated by N-iodosuccinimide (NIS) and triflic acid as the promoter, resulting in the desired alpha-seaside 6.
• With trisaccharide 6 obtained, glycosylation with GalN donor 4 is carried out using the p-TolSCl/AgOTf promoter system, resulting in the formation of protected GM2 7.
• The deprotection of GM2 7 occurs in four steps. The process begins with the hydrolysis of O-acetyl groups while simultaneously removing the Troc-protecting group. The amino group on GalN is then selectively acetylated using acetic anhydride in methanol. Afterward, the azido group is reduced through Staudinger reduction, and global debenzylation is carried out using Pearlman’s catalyst. These four deprotection steps result in the fully deprotected GM2 tetrasaccharide 1.

Fig.3 Synthesis of GM2. (CD BioGlyco, 2023)

Subsequently, we use the GM2 glycan obtained to prepare the GM2 conjugate vaccine by attaching the glycan to the carrier VLP bacteriophage Qβ. Previous research has shown that Qβ is more effective than other VLP platforms in boosting  immunity. Isothiocyanate chemistry is employed to introduce the GM2 glycan onto Qβ, resulting in the Qβ-GM2 conjugate. This conjugate is capable of inducing high levels of anti-GM2 antibodies, particularly IgG2 antibodies. These antibodies show the ability to bind GM2-expressing tumor cells and exhibit complement-dependent cytotoxicity, leading to the lysis of the tumor cells. These findings demonstrate that bacteriophage Qβ can serve as an effective vaccine platform for a GM2-based vaccine. We are currently conducting further research to optimize the structure of the GM2 antigen and the vaccine construct to enhance vaccine efficacy.

Applications

• GM2 ganglioside can be used as a key component in laboratory reagents and diagnostic tools. It can be used to detect related diseases or pathological conditions such as GM2 gangliosidosis and certain neurological disorders.
• GM2 ganglioside can serve as a target molecule for the development of tumor-associated carbohydrate vaccines. By combining GM2 Ganglioside with appropriate immune adjuvants, it can induce an immune response against GM2, which can be used for cancer treatment and immunotherapy research.
• GM2 ganglioside plays an important role in neurobiological research. It is involved in the formation and functional regulation of neuronal cell membranes and is associated with neuronal development, signal transduction, and synaptic function.

Advantages

• Our synthetic approach has the flexibility to prepare GM2 derivatives, such as GM2 lactones. This capability will allow us to further enhance the immunogenicity of the antigen.
• Our method offers high yield and stereoselectivity, allowing for efficient and specific reactions.
• Our method achieves high conversion efficiency by utilizing protective groups and selective functional group reactions.
• Our approach is straightforward to implement, without the need for additional steps to modify protective groups.
• We ensure specificity and selectivity by using specific reagents and reaction conditions to introduce modification groups at desired positions.
• Our methods effectively induce high titers and specificity of antibody production, as well as immune responses against target cells, by utilizing suitable carriers and immunogens.

From the initial identification of key targets to the development of intricate vaccine formulations, CD BioGlyco adheres to a rigorous and comprehensive approach. Our team of experts, advanced technology, and innovative approach set us apart. We excel at identifying key targets and formulating effective vaccines. If you have any interest in what we offer, please contact us.

References

1. van der Haar Àvila, I.; et al. Current state-of-the-art on ganglioside-mediated immune modulation in the tumor microenvironment. Cancer and Metastasis Reviews. 2023: 1-18.
2. Leal, A.F.; et al. GM2 gangliosidoses: clinical features, pathophysiological aspects, and current therapies. International journal of molecular sciences. 2020, 21(17): 6213.