Eggs, milk, peanuts, wheat, tree nuts, fish, crustacean shellfish, and soy are the eight foods that make up the “big eight” list of food allergens as released by the United States Department of Agriculture. Together these eight foods cause 90% of food allergies in people today. Wheat and peanuts, specifically, have been a target of the agricultural society in terms of creating a less allergenic form of these two foods. They want to be able to create more options for those who are allergic to wheat and peanuts because these two foods are used so widely across the world. Sachin Rustgi, a researcher in the Crop Science Society of America, decided to explore what possibilities are available to create less allergenic forms of wheat and peanuts. Rustgi, along with his colleagues, decided to turn to genetic engineering as a possible solution to this problem.
When referring specifically to wheat, there are a group of proteins, called gluten, that cause allergic reactions in individuals who suffer from celiac disease or are simply just gluten-sensitive. In order to create a less allergenic form of wheat, the researchers simply need to breed wheat with a lower gluten content. Seems easy, right? Well, not exactly. The most prevalent problem is that gluten is not a single protein but, instead, a group of proteins spread throughout different genes. So, the codes to make the gluten proteins do not all lie together, but in different parts of the wheats DNA. In terms of peanuts, the researchers ran into a similar problem. In fact, there are sixteen different proteins that can act as allergens in peanuts. Also in similarity to wheat, the allergen genes are spread throughout the DNA and are not grouped together. The dispersed characteristic of allergen genes in both wheat and peanuts forced Rustgi and his colleagues to use RNA Interference, also known as RNAi.
RNAi is a process that happens naturally but can also be mimicked by researchers for advantageous purposes. It involves RNA molecules inhibiting gene expression by making mRNA no longer able to bind to ribosomes or degrading the mRNA among other things. Out of the sixteen allergenic proteins in peanuts, four of them are extremely allergenic and cause most of the reactions from those who are sensitive to peanuts. That being said, the research team decided to use RNAi to focus on those four major proteins in peanuts. The researchers were also able to identify a “master gene” in gluten, so they targeted that specific gene using RNAi. However, these efforts only decreased the allergen problem. Since they were unable to reach all allergenic proteins in both wheat and peanuts they could only produce a less allergenic form of wheat or peanuts.
Then, Rustgi and his team decided to turn to a different form of biotechnology: CRISPR-Cas9. CRISPR works by allowing the scientists to target a specific gene and then change or mutate that gene by making the gene nonfunctional. This is efficient because CRISPR can target many different genes and it is extremely precise.
Rustgi, as well as his colleagues, are still working with biotechnology to create less allergenic versions of wheat and peanuts. This would allow for much more variation for those who suffer from these specific food allergies as well as help those individuals to avoid accidental exposure. Biotechnology just might be paving the way for a better future for those with food allergies!