Carbohydrate microarray for profiling the antibodies interacting with Globo H tumor antigen

Area of Science:

• Carbohydrate Chemistry
• Glycobiology
• Immunology

Background:

• Cell-surface carbohydrate interactions with antibodies and receptors are crucial for developing targeted therapeutics and sensitive diagnostics.
• Current methods are limited by the availability of natural oligosaccharides and assay sensitivity.
• The cancer antigen Globo H hexasaccharide is a key epitope on various cancer cell surfaces.

Purpose of the Study:

• To synthesize Globo H hexasaccharide and its truncated sequences using a programmable one-pot strategy.
• To develop a sensitive platform for analyzing antibody and serum binding specificities.
• To define the binding requirements of monoclonal antibodies and patient serum to Globo H epitopes.

Main Methods:

• Programmable one-pot synthesis of Globo H hexasaccharide and truncated sequences.
• Covalent arraying of synthesized saccharides on glass slides at varying densities.
• Fluorescence-based binding analysis using monoclonal antibodies and breast cancer patient serum.

Main Results:

• The terminal tetrasaccharide of Globo H binds monoclonal antibodies as effectively as the full hexasaccharide.
• The fucose residue is essential for effective binding of monoclonal antibodies.
• Patient serum showed similar binding to both fucosylated hexasaccharide and defucosylated pentasaccharide.

Conclusions:

• The developed method is highly sensitive and requires minimal material, outperforming traditional ELISA.
• This platform enables precise monitoring of immune responses to carbohydrate epitopes during cancer progression and treatment.
• Understanding Globo H binding specificities can inform the development of novel cancer diagnostics and therapeutics.