title: Expression of tetanus toxin Fragment C in tobacco chloroplasts.
abstract: Fragment C (TetC) is a non-toxic 47 kDa polypeptide fragment of tetanus toxin that can be used as a subunit vaccine against tetanus. Expression of TetC in Escherichia coli and yeast was dependent on the availability of synthetic genes that were required to improve translation efficiency and stabilize the mRNA. To explore the feasibility of producing TetC in tobacco leaves, we attempted expression of both the bacterial high-AT (72.3% AT) and the synthetic higher-GC genes (52.5% AT) in tobacco chloroplasts. We report here that the bacterial high-AT mRNA is stable in tobacco chloroplasts. Significant TetC accumulation was obtained from both genes, 25 and 10% of total soluble cellular protein, respectively, proving the versatility of plastids for expression of unmodified high-AT and high-GC genes. Mucosal immunization of mice with the plastid- produced TetC induced protective levels of TetC antibodies. Thus, expression of TetC in chloroplasts provides a potential route towards the development of a safe, plant-based tetanus vaccine for nasal and oral applications.
authors.affiliation: Waksman Institute, Rutgers University, 190 Frelinghuysen Road, Piscataway, NJ 08854-8020, USA.
authors.forename: John S
authors.initials: JS
authors.lastname: Tregoning
authors.forename: Peter
authors.initials: P
authors.lastname: Nixon
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kuroda
authors.forename: Zora
authors.initials: Z
authors.lastname: Svab
authors.forename: Simon
authors.initials: S
authors.lastname: Clare
authors.forename: Frances
authors.initials: F
authors.lastname: Bowe
authors.forename: Neil
authors.initials: N
authors.lastname: Fairweather
authors.forename: Jimmy
authors.initials: J
authors.lastname: Ytterberg
authors.forename: Klaas J
authors.initials: KJ
authors.lastname: van Wijk
authors.forename: Gordon
authors.initials: G
authors.lastname: Dougan
authors.forename: Pal
authors.initials: P
authors.lastname: Maliga
mesh_terms: D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D002736:Chloroplasts / Q000235:genetics*; D015870:Gene Expression; D007074:Immunoglobulin G / Q000276:immunology / Q000378:metabolism; D051379:Mice; D010446:Peptide Fragments / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D010936:Plant Extracts / Q000276:immunology; D018515:Plant Leaves / Q000737:chemistry; D030821:Plants, Genetically Modified; D010957:Plasmids / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013744:Tetanus Toxin / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics*
chemical_list: D007074:Immunoglobulin G; D010446:Peptide Fragments; D010936:Plant Extracts; D012333:RNA, Messenger; D013744:Tetanus Toxin; C040635:tetanus toxin fragment C