Xenoantigens derived from mammalian cells and animal source materials may be present as contaminants in the final product. These compounds are often problematic and must be identified. Among them, xenoantigen carbohydrates contained in pharmaceuticals have non-preferred effects and are difficult to detect because they are bound to proteins. Recent studies showed that some therapeutic antibodies and cell processing materials used in reproductive medicine contain the αGal epitope (Galα1-3Gal) and N-glycolylneuraminic acid (Neu5Gc). Therefore, rapid and robust methods for detecting the αGal epitope and Neu5Gc are required. We are working on improving these detection methods in multifarious ways.
We chemically synthesized various structure-defined N-glycans including human-type glycans (G0, G2, and SG), uniform isomers (6-G1 and 3-G1), and heterogenic antigens including αGal or Neu5Gc. We also produced high-grade 2-AB-labeled N-glycans. These compounds can be used as reliable and suitable standards for mass spectrometry, capillary electrophoresis, and high-performance liquid chromatography analyses. We introduce the use of these standard products with examples.
Antibodies for versatile detection
We simultaneously developed polyclonal antibodies that specifically bind to xenoantigen carbohydrates, αGal, and Neu5Gc using chickens as immunization hosts and the synthetic carbohydrate as an antigen. Some antibodies were modified with fluorescent probes or enzymes for versatile detection. The xenoantigen carbohydrate attached to Fc and/or Fab regions of the therapeutic antibody can be detected using our method. In this poster, we describe this method for detecting xenoantigen carbohydrates in cell culture supernatants or in therapeutic proteins using our antibodies.