Generation and validation of murine monoclonal and camelid recombinant single domain antibodies specific for human pancreatic glycoprotein 2.

Pancreatic secretory zymogen-granule membrane glycoprotein 2 (GP2) has been identified as a major autoantigenic target in Crohn's disease patients. It was reported recently that a long (GP2a) and a short (GP2b) isoform of GP2 exist and that in the outcome of inflammatory bowel diseases (IBD) GP2-specific autoantibodies probably appear as new serological markers for diagnosis and therapeutic monitoring. To investigate this further and in order to establish diagnostic tools for the discrimination of both GP2 isoforms, a set of different murine monoclonal and camelid recombinant single domain antibodies (camelid VHH) was generated and validated in various enzyme-linked immunosorbent assay (ELISA) formats, immunofluorescence on transgenic cell lines and immunohistochemistry on monkey pancreas tissue sections.

Generation of murine monoclonal antibodies with specificity against conventional camelid IgG1 and heavy-chain only IgG2/3.

Camelids possess antibodies with a conventional four-chain structure consisting of two heavy and two light chains (of subclass IgG1) but further they also generate heavy-chain only antibodies (of subclass IgG2 and 3) which are fully functional in antigen binding. In this study subclass-specific murine monoclonal antibodies specific to conventional camelid IgG1 and heavy-chain only IgG2/3 were generated and validated for the use as potent secondary detection reagents. The monoclonal antibodies are able to differentiate between all camelid IgGs, conventional four-chain camelid antibodies (of subclass IgG1) and exclusively heavy chain-only antibodies (of subclasses IgG2 and IgG3).