Canadian researchers have succeeded in producing a tobacco plant that contains a human gene that expresses the cytokine interleukin 10. They hope to produce enough of the cytokine to be able to make an oral anti-inflammatory vaccine for bowel diseases and certain autoimmune diseases.
The first plants containing the gene were grown in a laboratory, and the first field tests in Canada of a plant bearing a human gene will be conducted soon, according to Dr Anthony Jevnikar, the leader of the project.
Cytokines, which are biological response modifiers, are too expensive to manufacture synthe-tically for the type of oral treatment envisioned. Dr Jevnikar’s group had previously developed an oral vaccine, for protection against autoimmune diseases, and the current project originated from that work. In the earlier work, they fed plants containing a different protein (not interleukin 10) to mice that were prone to developing diabetes; feeding the mice these plants seemed to protect them from the disease.
“What we want to do is maximise this effect, and we engineered these plants to produce this cytokine to do that. But interleukin 10 is used for other medical purposes too, [such as] transplant rejection, which we’re also working on,” said Dr Jevnikar.
Dr Jevnikar, a nephrologist and transplant specialist, heads the transplant research group at the Robarts Research Institute, University of Western Ontario. Many of his patients have diabetes and are on dialysis awaiting transplantation.
The other group leader is Dr Jim Brandle, who is a research scientist with the federal agriculture department. The tobacco plant is considered to be especially useful in producing interleukin 10 because it is not a food crop, it can be segregated from other plants, and it dies during the winter, thus allaying concerns that the engineered genes could spread to other plants.