Improved Virus Neutralization by Plant-produced Anti-HIV Antibodies with a Homogeneous β1,4-Galactosylated N-Glycan Profile

• Published in: The Journal of biological chemistry Vol. 284; no. 31; pp. 20479 - 20485
• Main Authors: Strasser, Richard, Castilho, Alexandra, Stadlmann, Johannes, Kunert, Renate, Quendler, Heribert, Gattinger, Pia, Jez, Jakub, Rademacher, Thomas, Altmann, Friedrich, Mach, Lukas, Steinkellner, Herta
• Format: Journal Article
• Language: English
• Published: 9650 Rockville Pike, Bethesda, MD 20814, U.S.A Elsevier Inc 31.07.2009; American Society for Biochemistry and Molecular Biology
• Subjects: Glycobiology and Extracellular Matrices
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M109.014126

It is well established that proper N-glycosylation significantly influences the efficacy of monoclonal antibodies (mAbs). However, the specific immunological relevance of individual mAb-associated N-glycan structures is currently largely unknown, because of the heterogeneous N-glycan profiles of mAbs when produced in mammalian cells. Here we report on the generation of a plant-based expression platform allowing the efficient production of mAbs with a homogeneous β1,4-galactosylated N-glycosylation structure, the major N-glycan species present on serum IgG. This was achieved by the expression of a highly active modified version of the human β1,4-galactosyltransferase in glycoengineered plants lacking plant-specific glycosylation. Moreover, we demonstrate that two anti-human immunodeficiency virus mAbs with fully β1,4-galactosylated N-glycans display improved virus neutralization potency when compared with other glycoforms produced in plants and Chinese hamster ovary cells. These findings indicate that mAbs containing such homogeneous N-glycan structures should display improved in vivo activities. Our system, using expression of mAbs in tobacco plants engineered for post-translational protein processing, provides a new means of overcoming the two hurdles that limit the therapeutic use of anti-human immunodeficiency virus mAbs in global health initiatives, low biological potency and high production costs.