Improved Virus Neutralization by Plant-produced Anti-HIV Antibodies with a Homogeneous β1,4-Galactosylated N-Glycan Profile*
- Richard Strasser‡,
- Alexandra Castilho‡,
- Johannes Stadlmann§,
- Renate Kunert¶,
- Heribert Quendler‖**,
- Pia Gattinger‡,
- Jakub Jez‡,
- Thomas Rademacher‡‡,
- Friedrich Altmann§,
- Lukas Mach‡ and
- Herta Steinkellner‡,1
- From the ‡Department of Applied Genetics and Cell Biology,
- §Department of Chemistry, and
- ¶Institute of Applied Microbiology, University of Natural Resources and Applied Life Sciences, 1190 Vienna, Austria,
- ‖Polymun Scientific GmbH, 1190 Vienna, Austria,
- the **Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California 92037, and
- ‡‡Rheinisch-Westfälische Technische Hochschule, 52074 Aachen, Germany
- 1 To whom correspondence should be addressed: Muthgasse 18, 1190 Vienna, Austria. Tel.: 43-1-36006-6700; Fax: 43-1-36006-6392; E-mail: herta.steinkellner{at}boku.ac.at.
Abstract
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.
Footnotes
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↵3 H. Steinkellner, unpublished results.
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↵* This work was supported by the Wiener Wissenschafts-, Forschungs-, und Technologiefonds Project LS154.
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↵
The on-line version of this article (available at http://www.jbc.org) contains supplemental Figs. 1 and 2.
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↵2 The abbreviations used are:
- HIV-1
-
human immunodeficiency virus, type 1
- HIV
-
human immunodeficiency virus
- mAb
-
monoclonal antibody
- CHO
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Chinese hamster ovary cells
- Gn
-
N-acetylglucosamine
- ST
-
α2,6-sialyltransferase
- GalT
-
β1,4-galactosyltransferase
- CTS
-
cytoplasmic-transmembrane-stem
- HRP
-
horseradish peroxidase
- RCA
-
Ricinus communis agglutinin
- LC-ESI-MS
-
liquid chromatography-electrospray ionization-mass spectrometry
- WT
-
wild type.
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- Received February 24, 2009.
- Revision received April 29, 2009.
