A New Twist on Transgenes and Allergies

ResearchBlogging.orgWhen you bring up GE crops to people, one of the common objections is “Can’t these GMOs cause allergies?” Sure it is possible, as with any plant genetic modification (including breeding), which is why GE crops are tested for allergenicity according to regulations.

But now, it seems, the opposite may be true. “Can’t we use GMOs to eliminate allergies?”

The New Scientist reports that one Japanese researcher and his team are having some success with that possibility. 20% of Japanese citizens succumb to a harsh reaction to Japanese Cedar pollen. Proteins within the pollen cause the body to react as it would to an invading pathogen, which is what defines an allergy. Treatment currently requires pollen injections, which can be dangerous.

The new rice, which has been tested in mice and Macaques with no side effects, helps the body learn to tolerate the presence of those allergenic proteins. How does it work?

It is genetically modified to contain the seven proteins within cedar pollen that provoke the most serious allergic reactions in people.

Once in the intestine, the proteins damp down allergic responses through so-called “oral tolerance”. This is a process, controlled by lymph nodes, by which the immune system “learns” not to overreact to harmless foreign material such as food.

To stop the proteins being digested before they can have their effect, the rice was engineered to produce them in the endoplasmic reticulum, a part of rice plant cells that passes undigested through the stomach.

Pretty amazing! Before, people were worried that a genetically engineered protein in GE crops would survive digestion and cause allergies, but it appears that in order to make this work, they had to essentially cause the protein to survive digestion.

(I would like to point out an error in the New Scientist – the rice was not engineered with seven proteins. They made a “hybrid peptide” of the seven major allergy-causing epitopes. What this means is that they took the parts of those seven proteins that the immune system recognizes – known as epitopes – and put them together in a single protein.)

This brings up several questions. First, how would the public react to this rice in Japan? Japan is not known for being keen on GE crops, although they have many active research projects going on in the public and private sector. Would a rice such as this that could provide direct, accessible benefits to 20% of the population positively affect resistance to the technology?

Alternately, it could raise other objections. Although rice is self-pollinated, and a pretty good system for keeping unwanted cross-pollination out, people might object to allergenic proteins put into their major staple crop. Not only would this rice need a good human safety assessment for scientific reasons, it would need it for social reasons too.

The researchers are also investigating a similar GE rice that should help people with allergies to dust mites. Any chance they could make one to help with Ragweed pollen allergies? It’s my nemesis.

There are many traits in GE crops that are in development, already exist and are being tested, or are only now being conceived of. Whereas the first generation of these only really helped the farmers, the next generation will undoubtedly benefit and appeal to consumers. I have predicted before that there will be a cultural collision between those who are ideologically opposed to GE crops, and those who are wary of them because they get no tangible, direct benefits.

But what will be the shape of this collision? Will it be a sharp division between people who may now actively seek certain GE crops and those who want to avoid them, or will it be a slow trend from opposition to acceptance?

In any case, it seems that for now, the only long-term solution to ragweed pollen is a dose of local Honey, which I also highly endorse.

Domon, E., Takagi, H., Hirose, S., Sugita, K., Kasahara, S., Ebinuma, H., & Takaiwa, F. (2009). 26-Week Oral Safety Study in Macaques for Transgenic Rice Containing Major Human T-Cell Epitope Peptides from Japanese Cedar Pollen Allergens Journal of Agricultural and Food Chemistry, 57 (12), 5633-5638 DOI: 10.1021/jf900371u
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Karl earned his Ph.D. in Plant Breeding and Plant Genetics at UW-Madison, with a minor in Life Science Communication. His dissertation was on both the genetics of sweet corn and plant genetics outreach. He recently moved back to his home state of California. His favorite produce might just be squash.