Expression of the B subunit of Escherichia coli heat-labile enterotoxin as a fusion protein in transgenic tomato

Plant Cell Rep. 2003 Jun;21(10):1020-6. doi: 10.1007/s00299-003-0619-4. Epub 2003 Apr 11.


Epitopes often require co-delivery with an adjuvant or targeting protein to enable recognition by the immune system. This paper reports the ability of transgenic tomato plants to express a fusion protein consisting of the B subunit of the Escherichia coli heat-labile enterotoxin (LTB) and an immunocontraceptive epitope. The fusion protein was found to assemble into pentamers, as evidenced by its ability to bind to gangliosides, and had an average expression level of 37.8 microg g(-1) in freeze-dried transgenic tissues. Processing of selected transgenic fruit resulted in a 16-fold increase in concentration of the antigen with minimal loss in detectable antigen. The species-specific nature of this epitope was shown by the inability of antibodies raised against non-target species to detect the LTB fusion protein. The immunocontraceptive ability of this vaccine will be tested in future pilot mice studies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Antigens, Bacterial / genetics
  • Antigens, Bacterial / immunology
  • Antigens, Bacterial / metabolism
  • Bacterial Toxins / genetics
  • Bacterial Toxins / immunology
  • Bacterial Toxins / metabolism*
  • Bacterial Vaccines / immunology
  • Base Sequence
  • Enterotoxins / genetics
  • Enterotoxins / immunology
  • Enterotoxins / metabolism*
  • Enzyme-Linked Immunosorbent Assay
  • Escherichia coli / genetics*
  • Escherichia coli / immunology
  • Escherichia coli Proteins*
  • Fruit / genetics
  • Gene Expression
  • Lycopersicon esculentum / genetics*
  • Molecular Sequence Data
  • Plants, Genetically Modified
  • Protein Binding
  • Protein Subunits / genetics
  • Protein Subunits / immunology
  • Protein Subunits / metabolism
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / immunology
  • Recombinant Fusion Proteins / metabolism
  • Species Specificity
  • Transgenes / genetics


  • Antigens, Bacterial
  • Bacterial Toxins
  • Bacterial Vaccines
  • Enterotoxins
  • Escherichia coli Proteins
  • Protein Subunits
  • Recombinant Fusion Proteins
  • heat-labile enterotoxin, E coli