Glycosylation of plant produced human antibodies.

Abstract

Human immunoglobulins circulate as highly heterogeneously glycosylated mixture of otherwise homogeneous protein backbones. A series of studies, mainly on IgG, have unequivocally proven that antibodies modulate their effector function through sugars present in the Fc domain. However, our limited technology in producing complex proteins such as antibodies, with defined glycan structures hamper in depths studies. This review introduces a plant based expression platform enabling engineering of antibody glycans. The procedure is based on the simultaneous delivery of appropriate constructs, carrying cDNAs of target proteins (e.g. heavy and light chain of antibodies) in combination with human glycosylation enzymes into plant leaves. Harvesting of recombinant proteins one week post construct delivery allows high speed and flexibility. Major achievements include the production of functional active slialylated pentameric IgMs in tobacco leaves. The system provides a viable approach to the generation of antibodies with defined glycoforms on demand, contributing to studies on antibody glycans and the development of novel antibody based drugs.