Open AccessAn antibody produced in tobacco expressing a hybrid β-1,4-galactosyltransferase is essentially devoid of plant carbohydrate epitopes
Author(s) -
Hans Bakker,
Gerard Rouwendal,
Anton S. Karnoup,
D.E.A. Florack,
Geert Stoopen,
J.P.F.G. Helsper,
Ronald van Ree,
Irma van Die,
Dirk Bosch
Publication year - 2006
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.0600879103
Subject(s) - galactosyltransferase , fucose , epitope , biochemistry , glycan , glycosylation , immunogenicity , transgene , biology , monoclonal antibody , chemistry , microbiology and biotechnology , galactose , antibody , glycoprotein , enzyme , gene , immunology
N-glycosylation of a mAb may have a major impact on its therapeutic merits. Here, we demonstrate that expression of a hybrid enzyme (called xylGalT), consisting of the N-terminal domain of Arabidopsis thaliana xylosyltransferase and the catalytic domain of human beta-1,4-galactosyltransferase I (GalT), in tobacco causes a sharp reduction of N-glycans with potentially immunogenic core-bound xylose (Xyl) and fucose (Fuc) residues as shown by Western blot and MALDI-TOF MS analysis. A radioallergosorbent test inhibition assay with proteins purified from leaves of WT and these transgenic tobacco plants using sera from allergic patients suggests a significant reduction of potential immunogenicity of xylGalT proteins. A mAb purified from leaves of plants expressing xylGalT displayed an N-glycan profile that featured high levels of galactose, undetectable xylose, and a trace of fucose. Hence, a transgenic plant expressing the hybrid GalT might yield more effective and safer monoclonals for therapeutic purposes than WT plants and even transgenic plants expressing the unchanged GalT.