Antibodies are excellent tools for protein research. Provided they have the desired affinity, specificity and functionality, they allow elucidating different aspects of the protein of interest.
Previously, we generated several VHHs against Arabidopsis thaliana seed storage proteins and implemented them as primary antibodies in ELISA, electron microscopy and affinity purification (De Meyer et al., 2014). Subsequently, these VHHs were produced as bivalent VHH-Fc antibodies in Nicotiana benthamiana leaves and Pichia pastoris (De Meyer et al., 2015). By making bivalent VHH-Fc antibodies, the VHH binding specificities are retained and sometimes augmented in terms of sensitivity by Fc-based avidity effects and signal amplification with secondary anti-Fc antibodies. Moreover, the Fc chain is a robust protein tag for purification and immunodetection, and provides effector functions.
Currently, together with the Stoger lab (Vienna), these VHH-Fcs are being evaluated as immunomodulators in Arabidopsis thaliana seeds, where they potentially interfere with antigen folding, localization and/or functioning in vivo.
De Meyer, T., Eeckhout, D., De Rycke, R., De Buck, S., Muyldermans, S. and Depicker, A. (2014) Generation of VHH antibodies against the Arabidopsis thaliana seed storage proteins. Plant Mol. Biol. 84, 83-93.
De Meyer, T., Laukens, B., Nolf, J., Van Lerberge, E., De Rycke, R., Debeuckelaer, A., De Buck, S., Callewaert, N., and Depicker, A. (2015). Comparison of VHH-Fc antibody production in Arabidopsis thaliana, Nicotiana benthamiana and Pichia pastoris. Plant Biotechnol. J., in press.