Plantibodies and Edible Vaccines

Tobacco-Derived HIV-Neutralizing Antibody

http://www.scientificamerican.com/article.cfm?id=cancer-vaccine-tobacco-plants

Mackenzie Owen

General HIV Information HIV, or Human Immunodeficiency Virus, is a

virus that destroys specific blood cells, T cells, which help the body fight disease.

People who are infected with HIV may or may not show symptoms.

Approximately 35 million people are living with HIV according to the World Health Organization in 2011.

Plantibodies Plantibody—plant-derived antibodies

Producing recombinant proteins in plants has many advantages for generating biopharmaceuticals that are relevant to medicine.

Large scale production of antibodies in plants is more cost effective than using mammalian cells.

Edible vaccines can bypass the purification of the antibody.

Tobacco-Derived HIV-Neutralizing Antibody

Two monoclonal antibodies (mAbs) with HIV neutralizing activity, mAbs 2F5 and mAbs 2G12, have been expressed in plants.

Doreen Floss and colleagues conducted an experiment that produced the 2G12 antibody in transgenic tobacco plants.• Transgenic tobacco plants were generated accumulating four

different formats of the anti-HIV-1 antibody 2G12 in the ER.• The plant-derived 2G12 antibodies showed the same or

better in vitro HIV-neutralization properties as CHO-derived 2G12 antibodies.

Doreen M. Floss et al. (2009)

Full-length 2G12 antibodies and ELP fusion proteins produced by transgenic tobacco plants.

Floss et al. (2009) Full-length 2G12 antibodies and ELP fusion

proteins produced by transgenic tobacco plants.

Floss et al. (2009) Full-length 2G12 antibodies and ELP fusion

proteins produced by transgenic tobacco plants.

Floss et al. (2009) Full-length 2G12 antibodies and ELP fusion

proteins produced by transgenic tobacco plants.

Floss et al. (2009) Purification and characterization of 2G12

antibodies from tobacco plants.

Floss et al. (2009) Purification and characterization of 2G12

antibodies from tobacco plants.

Floss et al. (2009) Differential N-glycosylation of 2G12 heavy

chains in tobacco leaves and seeds.

Floss et al. (2009) Antigen binding

properties of the recombinant antibodies

Floss et al. (2009) Differential N-glycosylation of 2G12 heavy

chains in tobacco leaves and seeds.

Floss et al. Conclusion Kinetic binding parameters of the tobacco-derived 2G12

antibody formats were identical to the 2G12 produced in CHO cells that lack ELP.

• Purification of the protein from seed by inverse transition cycling (ITC) did not affect the binding kinetics

Retrieval to the ER was efficient for the four formats and was seen after analysis of the heavy chain N-glycans from the antibodies derived from leaves.

HIV-neutralization properties of the tobacco 2G12 antibody was the same as or better than the CHO 2G12 antibody.

References Floss, Doreen M., Markus Sack, Elsa Arcalis, Johannes Stadlmann, Heribert Quendler, Thomas

Rademacher, Eva Stoger, Jurgen Fischer, and Udo Conrad. 2009. “Influence of elastin-like peptide fusions on the quantity and quality of a tobacco-derived human immunodeficiency virus-neutralizing antibody.” Plant Biotechnology Journal (2009) 7, pp. 899-913.

Daniell, Henry, Stephen J. Streatfield, and Keith Wycoff. 2001. “Medical molecular farming: production of antibodies, biopharmaceuticals and edible vaccines in plants.” TRENDS in Plant Science Vol. 6 No. May 2001.

CDC.gov. The Center for Disease Control and Prevention. Last Updated: 11 Apr 2012. Viewed: 23 Nov 2012. http://www.cdc.gov/hiv/topics/basic/index.htm

WHO.int. The World Health Organization. 2011. “Global summary of the AIDS epidemic.” Viewed: 23 Nov 2012. http://www.who.int/hiv/data/2012_epi_core_en.png