The antibody production method developed by the Stanford University researchers can produce recombinant idiotype vaccines in a matter of days, rather than the months needed using traditional techniques that grow the vaccines in animal or bacteria cells.
This increased speed of development and production could enable personalised vaccines against a whole range of challenging diseases to be produced, a particularly important factor when dealing with cancers that have unique antibody markers.
The study, published in an advanced online issue of the Proceedings of the National Academy of Sciences (PNAS) described the first-in-man Phase I safety trial of the tobacco-produced vaccines against follicular B-cell lymphoma.
Follicular B-cell lymphoma is an immune-system malignancy that is widely viewed as a chronic, incurable disease which is diagnosed in around 16,000 people every year.
The standard chemotherapy treatments available have such severe side effects that patients often opt to carefully watch the progression of the disease in the early stages of the illness.
The trial tested the single chain antibody (ScFv) vaccines produced by the tobacco plants on 16 newly diagnosed follicular B-cell lymphoma patients and none of them experienced any side effects from the tobacco-grown vaccines.
While the efficacy of the antibodies is yet to be proven in a large scale study, more than 70 per cent of the patients developed cellular or humoral immune responses and 47 per cent developed antigen-specific responses.
The researcher’s vaccination strategy involved injecting many copies of the cancer-specific antibody into newly diagnosed lymphoma patients and stimulating their immune system to destroy the malignant cells.
"This would be a way to treat cancer without side effects," said Professor Ronald Levy, of Stanford University’s the School of Medicine, and lead author of the report.
"The idea is to marshal the body's own immune system to fight cancer."
The antibody production technique involves isolating the relevant antibody from a patient’s tumour and inserting the gene that codes for the antibody into the easily modifiable tobacco mosaic virus (TMV). The tobacco plant is then infected with the virus by simply scratching the virus onto its leaves.
The virus takes the gene into the plant’s cells which rapidly produce the antibodies. After a few days the plant’s leaves can be harvested so that the antibody can be extracted and purified.
"It's pretty cool technology, and it's really ironic that you would make a treatment for cancer out of tobacco," said Prof. Levy
Bayer has recently opened a pilot-scale production facility in Germany where it hopes to use a similar tobacco plant TMV-infection method to produce therapeutic proteins.