| Autor: |
Hamorsky KT; 1] Owensboro Cancer Research Program of James Graham Brown Cancer Center at University of Louisville School of Medicine, Owensboro, KY, USA [2] Department of Medicine, University of Louisville School of Medicine, Louisville, KY, USA., Kouokam JC; 1] Owensboro Cancer Research Program of James Graham Brown Cancer Center at University of Louisville School of Medicine, Owensboro, KY, USA [2] Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY, USA., Jurkiewicz JM; Owensboro Cancer Research Program of James Graham Brown Cancer Center at University of Louisville School of Medicine, Owensboro, KY, USA., Nelson B; Owensboro Cancer Research Program of James Graham Brown Cancer Center at University of Louisville School of Medicine, Owensboro, KY, USA., Moore LJ; Owensboro Cancer Research Program of James Graham Brown Cancer Center at University of Louisville School of Medicine, Owensboro, KY, USA., Husk AS; Owensboro Cancer Research Program of James Graham Brown Cancer Center at University of Louisville School of Medicine, Owensboro, KY, USA., Kajiura H; The International Center for Biotechnology, Osaka University, Osaka, Japan., Fujiyama K; The International Center for Biotechnology, Osaka University, Osaka, Japan., Matoba N; 1] Owensboro Cancer Research Program of James Graham Brown Cancer Center at University of Louisville School of Medicine, Owensboro, KY, USA [2] Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY, USA. |
| Abstrakt: |
Plant-based transient overexpression systems enable rapid and scalable production of subunit vaccines. Previously, we have shown that cholera toxin B subunit (CTB), an oral cholera vaccine antigen, is N-glycosylated upon expression in transgenic Nicotiana benthamiana. Here, we found that overexpression of aglycosylated CTB by agroinfiltration of a tobamoviral vector causes massive tissue necrosis and poor accumulation unless retained in the endoplasmic reticulum (ER). However, the re-introduction of N-glycosylation to its original or an alternative site significantly relieved the necrosis and provided a high CTB yield without ER retention. Quantitative gene expression analysis of PDI, BiP, bZIP60, SKP1, 26Sα proteasome and PR1a, and the detection of ubiquitinated CTB polypeptides revealed that N-glycosylation significantly relieved ER stress and hypersensitive response, and facilitated the folding/assembly of CTB. The glycosylated CTB (gCTB) was characterized for potential vaccine use. Glycan profiling revealed that gCTB contained approximately 38% plant-specific glycans. gCTB retained nanomolar affinity to GM1-ganglioside with only marginal reduction of physicochemical stability and induced an anti-cholera holotoxin antibody response comparable to native CTB in a mouse oral immunization study. These findings demonstrated gCTB's potential as an oral immunogen and point to a potential role of N-glycosylation in increasing recombinant protein yields in plants. |
