title: Recombinant monoclonal antibody yield in transgenic tobacco plants is affected by the wounding response via an ethylene dependent mechanism.
abstract: Variability in recombinant IgG yield in transgenic tobacco plants has previously been observed in relation to leaf position, and is interpreted as a function of ageing and the senescence process, leading to increasing protein degradation. Here, similar findings are demonstrated in plants of different ages, expressing IgG but not IgG-HDEL, an antibody form that accumulates within the endoplasmic reticulum. Antibody yields declined following wounding in young transgenic plants expressing IgG but not in those expressing IgG-HDEL. However, in mature IgG plants, the opposite was demonstrated, with significant boosts in yield, while mature IgG-HDEL plants could not be boosted. The lack of response in IgG-HDEL plants suggests that the changes induced by wounding occur post-translationally, and the findings might be explained by wounding responses that differ in plants according to their developmental stages. Plant mechanisms involved in senescence and wounding overlap to a significant degree and compounds such as ethylene, jasmonic acid and salicylic acid are important for mediating downstream effects. Treatment of transgenic plants with ethylene also resulted in a decrease in recombinant IgG yield, which was consistent with the finding that wounded plants could induce lower IgG yields in neighbouring non-wounded plants. Treatment with 1-MCP, an ethylene antagonist, abrogated the IgG yield drop that resulted from wounding, but had no effect on the more gradual IgG yield loss associated with increasing plant age.
authors.affiliation: CMM, 2nd Floor Jenner Wing, St. George's Hospital Medical School, Cranmer Terrace, London SW17 0RE, UK.
authors.forename: Sally
authors.initials: S
authors.lastname: Hassan
authors.forename: Richard
authors.initials: R
authors.lastname: Colgan
authors.forename: Mathew J
authors.initials: MJ
authors.lastname: Paul
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Atkinson
authors.forename: Amy L
authors.initials: AL
authors.lastname: Sexton
authors.forename: Craig J
authors.initials: CJ
authors.lastname: van Dolleweerd
authors.forename: Eli
authors.initials: E
authors.lastname: Keshavarz-Moore
authors.forename: Julian K-C
authors.initials: JK
authors.lastname: Ma
mesh_terms: D000911:Antibodies, Monoclonal / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D003521:Cyclopropanes / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D005030:Ethylenes / Q000494:pharmacology*; D018506:Gene Expression Regulation, Plant; D007074:Immunoglobulin G / Q000235:genetics / Q000378:metabolism*; D018515:Plant Leaves / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism*; D014026:Nicotiana / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*
chemical_list: D000911:Antibodies, Monoclonal; D003521:Cyclopropanes; D005030:Ethylenes; D007074:Immunoglobulin G; D011994:Recombinant Proteins; C105498:1-methylcyclopropane