Transient Production of Human β-Glucocerebrosidase With Mannosidic-Type -Glycan Structure in Glycoengineered Plants.

Gaucher disease is an inherited lysosomal storage disorder caused by a deficiency of functional enzyme β-glucocerebrosidase (GCase). Recombinant GCase has been used in enzyme replacement therapy to treat Gaucher disease. Importantly, the terminal mannose -glycan structure is essential for the uptake of recombinant GCase into macrophages via the mannose receptor. In this research, recombinant GCase was produced using -mediated transient expression in both wild-type (WT) and -acetylglucosaminyltransferase I (GnTI) downregulated (ΔgntI) plants, the latter of which accumulates mannosidic-type -glycan structures. The successfully produced functional GCase exhibited GCase enzyme activity. The enzyme activity was the same as that of the conventional mammalian-derived GCase. Notably, -glycan analysis revealed that a mannosidic-type -glycan structure lacking plant-specific -glycans (β1,2-xylose and α1,3-fucose residues) was predominant in all glycosylation sites of purified GCase produced from ΔgntI plants. Our research provides a promising alternative plant line as a host for the production of recombinant GCase with a mannosidic-type -glycan structure. This glycoengineered plant might be applicable to the production of other pharmaceutical proteins, especially mannose receptor targeted protein, for therapeutic uses.