Attack of the (Alzheimer’s) Killer Tomatoes

Transgenic tomatoes expressing beta-amyloaid may serve as a vaccine against the dreaded neurodegenerative disease.

BY DANIEL S. LEVINE

The 1978 classic Attack of the Killer Tomatoes showed just how terrifying the marauding fruit could be, but can the little suckers be harnessed for good instead of evil?

That’s the plan from scientists in South Korea, who have created a genetically altered tomato in the hopes of eventually vaccinating people against Alzheimer’s disease. Though it may sound like a kitschy sci-fi plot, a study published in the journal Biotechnology Letters reports that researchers at the Korea Research Institute of Bioscience and Biotechnology, Digital Biotech, and Wonkwang University have taken the first steps toward finding an edible vaccine against the neurodegenerative disease.

Alzheimer’s is thought to be caused by the accumulation of human beta-amyloid, a toxic insoluble fibrous protein in the brain, which leads to the death of neurons. A primary therapeutic target for treating Alzheimer’s has been to target this telltale plaque that accumulates in the brain in the hopes of preventing or slowing the degeneration of neurons.

The South Korean researchers are hoping to stimulate the immune system to reduce beta-amyloid by producing a genetically altered tomato that contains the amyloid-beta gene and can induce amyloid-beta antigens. This may be more preferable than producing the amyloid-beta through yeast or bacteria because it is toxic to these organisms.

The researchers said the tomato-derived amyloid-beta antigen stimulated the production of serum antibodies in mice and showed it was feasible to produce amyloid-beta protein in transgenic tomatoes and to use the fruit as a delivery system for oral immunization.

They also found that mice fed extract from transgenic tomatoes exhibited a significant increase in serum against amyloid-beta after boosting them with a commercial vaccine, compared to the primary antibody response. However, they did not find a reduction in existing plaques in the brain of mice given the tomato-derived vaccine.

For now, the researchers are pursuing strategies for boosting the potency of the tomato-based vaccine because of the low level of protein in fresh tomatoes.