New Tool to Aid the Detection of Alpha-1,3-Gal Glycans in Biopharmaceuticals

Adding to their range of glycan standards products, Ludger Ltd now offer a 2-AB labelled alpha-1,3-Gal standard (Cat No. CAB-ALPHAGAL-01). This glycan standard can be used during glycoprofiling as a positive control for sequencing experiments utilising alpha1-3 galactose specific exoglycosidase.

The presence of Gal alpha-1-3-Gal structures within biopharmaceuticals is of huge importance to the pharmaceutical industry. Gal alpha 1-3 Gal (also known as Alpha Gal) is a potentially immunogenic glycan which has been reported to be present in recombinant biological pharmaceuticals (Chung et al, 2008). It is found in the meat of non-primate mammals, cows milk and dog and cat dander. Humans cannot synthesize the glycan but can express antibodies against this structure (Galili et al, 1985). Anti-Gal antibodies comprise 1% of circulating IgG antibodies in all humans. An IgE-mediated allergic/hypersensitivity response to this glycan was observed in patients taking Cetuximab as a cancr treatment (Chung et al, 2008). Cetuximab is a chimeric murine-human cell monoclonal antibody. The cause for developing IgE antibodies specific to Alpha-Gal has been reported to occur after being bitten by certain types of tick; cases have been concentrated predominantly in the Southeast United States and parts of Australia. (Commins et al 2009; Van Nunen et al, 2009).

In humans the production of anti-Gal antibodies has presented a unique opportunity for developing methods that harness the immunologic potential of this antibody for clinically beneficial outcomes. Anti-Gal IgG molecules bound to -gal epitopes on particulate or soluble vaccines will target them to APC at the vaccination site, and induce effective uptake of the vaccine by APC (Galili, 2005).