Different subcellular localization and glycosylation for a functional antibody expressed in Nicotiana tabacum plants and suspension cells.
Genes encoding the heavy and light chains of LO-BM2, a therapeutic IgG antibody, were assembled in the tandem or inverted convergent orientation and expressed in Nicotiana tabacum plants and BY-2 suspension cells. The tandem construct allowed higher expression in both expression systems. A similar degradation pattern was observed for the secreted antibody recovered from the leaf intercellular fluid and BY-2 culture medium. Degradation increased with leaf age or culture time. Antibodies purified from leaf tissues and BY-2 cells were both functional. However, MS analysis of the N-glycosylation showed complex plant-type glycans to be the major type in the antibody purified from plants, whereas, oligomannosidic was the major glycosylation type in that purified from BY-2 cells. LO-BM2 was observed mainly in the endoplasmic reticulum of BY-2 cells while, in leaf cells, it was localized mostly to vesicles resembling prevacuolar compartments. These results and those from endoglycosidase H studies suggest that LO-BM2 is secreted from BY-2 cells more readily than from leaf cells where it accumulates in a post-Golgi compartment.
De Muynck
Benoit
B
Institut des Sciences de la Vie, Université catholique de Louvain, Louvain-la-Neuve, Belgium.
Navarre
Catherine
C
Nizet
Yannick
Y
Stadlmann
Johannes
J
Boutry
Marc
M
D000818:Animals; D000911:Antibodies, Monoclonal / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D002451:Cell Compartmentation; D002478:Cells, Cultured; D006031:Glycosylation; D006056:Golgi Apparatus / Q000378:metabolism; D006801:Humans; D007074:Immunoglobulin G / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D018515:Plant Leaves / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D007074:Immunoglobulin G