Comparison of Sugar Uptake between Wild-type and Glyco-engineered Rice Cells in Suspension Cultures

초록

N-glycans of proteins is important for their safely as well as efficacy in biopharmaceuticals. N-glycosylation pathway is different between mammalian and plant cells. For this reason, the use of plant-made pharmaceuticals (PMPs) has potential cause of immunogenicity. For that reason, glyco-engineering is required for the humanization of N-glycans. N-acetylglucosaminyltransferase 1 (gnt1) knockout is known to be an effective strategy that expresses high-mannose N-glycans lacking plant-specific residues. However, modulation of N-glycan has a possibility to affect the characteristics of the cells. Therefore, comparison of different characteristics between wild-type and glyco-engineered cells should be performed for the production of PMPs. For the comparison of sugar uptake, which is one of main nutrients in rice cell cultures, sucrose, glucose, fructose, mixtures of glucose and fructose were added into culture medium as carbon sources. Similar sugar uptake behavior was observed except sucrose. In case of sucrose, gnt1 knockout rice cells converted sucrose to glucose and fructose about 50 % ratio at the early stage of cultures (day 2), but wild-type cells showed low conversion of sucrose at 17 %. In conclusion, it was found that gnt1 knockout in rice cells could significantly influence sugar uptake behavior.