Glycan-Specific antibodies are a popular detection tool, diagnostic reagent, and therapeutic agent due to glycosylation occurring on characteristic and disease state-specific markers. For example, HIV-1 vaccine research has interest in targeting highly glycosylated protein gp120 for inactivating the virus envelope.
Challenge:
Developing antibodies against post-translationally modified glycan sugar residues presents many challenges such as low immunogenicity and specificity since carbohydrates are not well understood, the presentation and structure is complex, and it is not genomically encoded. For gp120, the surface consists of an array of exposed high-mannose glycans making the protein not very immunogenic and highly variable. In addition, to generate an antibody that will bind to the neutralizing glycan target of interest on gp120, we needed to induce carbohydrate specific HIV-1 cross-reactive IgG-class switched antibodies.
Solution:
Our experts used a proprietary immunogen design of protein Saccharomyces cervisiase and immunization regime to mimic the glycoslyated structure for a specific immune response for the target and induce IgG class-switched antibodies to glycan specific immunogens. The protocol successfully produced rabbit polyclonal antibodies binding to high mannose gylcans similar to the broadly neutralizing antibody 2G12 on gp120. REF to J Virol. 2008 Jul; 82(13): 6447–6457.Published online 2008 Apr 23. doi: 10.1128/JVI.00412-08