Human proteins to be made with use of tobacco plants

Could much maligned tobacco plant be used to help cancer patients? A California biotech company says it can, and it has set up shop in tobacco country to prove it.

Large Scale Biology of Vacaville, California, has built a commercial "biopharmaceutical production facility" in this Ohio River community of 54,000. It is one of a handful of companies harnessing plants to produce useful human proteins.

Genetic already use many different ploys to manufacture human proteins, such as insulin and growth hormones. Often, they isolate a human gene that carries the code for making a protein and splice it into yeast or bacteria, which multiply in fermentation vats.

Now, companies are doing the same thing by the acre. They hope molecular farming, as some call it, will be cheaper and more efficient.

"We borrow the plant's cellular machinery," said Barry Bratcher, Large Scale Biology's biomanufacturing director. "The plant is just a host for us."

Tobacco a big bulky plant that produces lots of greenery, and it is one scientists have already had plenty of practice genetically manipulating in the lab. Large Scale Biology has contracts with four local farmers to grow a combined 27 acres of tobacco for research.

"It is ironic that tobacco might actually be used to create health instead of reducing health," said chief executive officer Bob Erwin.

Already, the company has begun early stage testing of a tobacco-produced vaccine intended to trigger the body's immune system to fight non-Hodgkin's lymphoma. Each dose would be a customized protein, made by mutant genes taken from the patient's own cancer cells. In theory, the proteins should stimulate the body to turn against the cancer.

The company also is considering human testing of a treatment for Fabry's disease. The therapy is a tobacco-made copy of a normal human enzyme, needed to break down fats, that is missing in victims of the disease.

In earlier stages is a collaboration with the US Navy and the National Institutes of Health to use tobacco to make stem cells grow. The goal is to find a natural human protein that will multiply blood-forming stem cells that have been isolated from the bone marrow. A team of Navy and NIH researchers is attempting to produce a protein that will make blood stem cells divide repeatedly in a test tube. They already have evidence that the body makes such a protein. The collaboration with Large Scale Biology is intended to find the gene responsible so it can be manufactured in quantity.

Chute the protein could be extremely useful for conducting gene therapy to correct inherited blood diseases, such as sickle cell anemia.