Tobacco Plants Used to Produce Monoclonal Antibodies

J · medicine forum addict Joined: 07 May 2005 Posts: 93

http://www.monsanto.co.uk/news/ukshowlib.phtml?uid=8909
Wednesday, 4th May, 2005

Scientists at Jefferson Medical College are using tobacco plants to
produce monoclonal antibodies – tiny guided protein missiles – that can
target and hunt down cancer cells. The plants promise to provide a
cheaper, faster method of producing anticancer antibodies, raising hopes
that the technology can one day be used in humans.

Scientists, led by Hilary Koprowski, M.D., professor of microbiology and
immunology and director of the Biotechnology Foundation Laboratories and
the Center for Neurovirology at Jefferson Medical College of Thomas
Jefferson University in Philadelphia and Kisung Ko, Ph.D., an instructor
in the Department of Microbiology and Immunology at Jefferson Medical
College, inserted DNA coding for an antibody against colorectal cancer
into tobacco plants. The plants, in turn, become factories churning out
antibody.

The report appears online this week in the Proceedings of the National
Academy of Sciences.

Standard mouse-made monoclonals recognize a particular type of protein
antigen on human colorectal cancer cells and have been used in treating
metastatic disease and in preventing recurrence in certain high-risk
patients. But the technology to produce large amounts of antibody is
expensive, and researchers would like to find alternatives. Dr. Koprowski,
Dr. Ko and their co-workers had previously shown that tobacco plant-made
monoclonal antibodies could neutralize rabies virus and prevent disease in
infected mice. They wanted to find out if plant-made antibodies could be
effective for cancer immunotherapy.

They first showed that plant-made monoclonal antibody purified from
tobacco leaves could recognize, or bind to, human colorectal cancer cells.
Next, they grafted human colorectal cancer cells onto the backs of nude
mice – mice stripped of their immune systems, and subsequently injected
the animals with the plant-derived antibodies. Then they watched for tumor
growth for as many as 40 days.

The researchers found that tumor growth was inhibited in a similar manner
to that of mammalian-made monoclonal antibodies, Dr. Ko says.

“These results indicate that plant biotechnology can be a useful
alternative to produce monoclonal antibodies,” he says.

“The antibody produced in tobacco is as good as the antibody produced in
animal cells,” says Dr. Koprowski, noting that tobacco-derived antibody
should be safer and less expensive to produce.

References
1. The report appears online this week in the Proceedings of the National
Academy of Sciences.

Click here to view the original article.

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