Open AccessHigh‐yield expression of a viral peptide animal vaccine in transgenic tobacco chloroplasts
Author(s) -
Molina Andrea,
HervásStubbs Sandra,
Daniell Henry,
MingoCastel Angel M.,
Veramendi Jon
Publication year - 2004
Publication title -
plant biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.525
H-Index - 115
eISSN - 1467-7652
pISSN - 1467-7644
DOI - 10.1046/j.1467-7652.2004.00057.x
Subject(s) - biology , fusion protein , epitope , chloroplast , recombinant dna , virology , green fluorescent protein , antigen , cholera toxin , monoclonal antibody , microbiology and biotechnology , antibody , biochemistry , gene , genetics , immunology
Summary The 2L21 peptide, which confers protection to dogs against challenge with virulent canine parvovirus (CPV), was expressed in tobacco chloroplasts as a C‐terminal translational fusion with the cholera toxin B subunit (CTB) or the green fluorescent protein (GFP). Expression of recombinant proteins was dependent on plant age. A very high‐yield production was achieved in mature plants at the time of full flowering (310 mg CTB‐2L21 protein per plant). Both young and senescent plants accumulated lower amounts of recombinant proteins than mature plants. This shows the importance of the time of harvest when scaling up the process. The maximum level of CTB‐2L21 was 7.49 mg/g fresh weight (equivalent to 31.1% of total soluble protein, TSP) and that of GFP‐2L21 was 5.96 mg/g fresh weight (equivalent to 22.6% of TSP). The 2L21 inserted epitope could be detected with a CPV‐neutralizing monoclonal antibody, indicating that the epitope is correctly presented at the C‐terminus of the fusion proteins. The resulting chimera CTB‐2L21 protein retained pentamerization and G M1 ‐ganglioside binding characteristics of the native CTB and induced antibodies able to recognize VP2 protein from CPV. To our knowledge, this is the first report of an animal vaccine epitope expression in transgenic chloroplasts. The high expression of antigens in chloroplasts would reduce the amount of plant material required for vaccination (∼100 mg for a dose of 500 µg antigen) and would permit encapsulation of freeze‐dried material or pill formation.