Food Allergies Be Gone: Nanoparticles Call for an Immune Ceasefire

Milk, eggs, peanuts, tree nuts, wheat, soy, fish, and shellfish—these foods top the most unwanted list for the tens of millions of people in the U.S. living with food allergies. Data shows that sensitivities to these and other food-based allergens are on the rise. A report by the Centers for Disease Control & Prevention indicates that from 1997 to 2011, the prevalence of food allergies in children increased by a whopping 50 percent.

“Huge numbers of people suffer from food allergies, amounting to billions of dollars in annual health care costs,” explained André Nel, nanotechnology expert and author of a recent publication outlining the potential for nanomedicines as countermeasures against food allergies. 

“Normally, asthma and anaphylaxis are treated with an EpiPen syringe as well as anti-inflammatory and immune-suppressive drugs that only provide transient relief. For the problem to go away long-term, we’re looking at the liver to reprogram the immune system to an actively sustained state of nonresponsiveness.”

Nel and the team have developed a novel technique for reprogramming the overactive immune system in those with allergies by using a subset of anti-inflammatory lymphocytes called T regulatory cells. 

The message that these foods are harmless is sent by messengers that are undetectable to the human eye. Size matters with these carriers— nanoparticles have distinct physical and chemical properties from their larger material counterparts. Once administered into the bloodstream, the nanoparticles’ final destination is the liver.

This organ is unique in that instead of mounting an attack on foreign antigens, the liver’s specialized immune system favors tolerance over immunity. In their report, published in ACS Nano, the team demonstrates how delivering a single allergy-causing protein to the liver within a nanoparticle carrier is enough to provide long-term relief. 

The scientists performed a series of experiments in a mouse model of egg allergy. When the mice were exposed to egg proteins, they would display asthma-like symptoms such as difficulty breathing. Nanoparticles were administered to the animals, which sequestered in the liver and triggered the production of regulatory T cells, programmed specifically to stem allergic reactions against the egg protein. The nanoparticle treatment prevented the onset of allergic reactions.

“These results are very exciting,” said the first author of the study, Qi Liu. “Our preliminary studies showed that our nanoparticles could successfully target cells in the liver and generate regulatory T cells to alleviate inflammation in the airways, and these experiments demonstrated that the platform is also effective against food allergies.”

Follow-up experiments will expand the potential application of this nanotechnology-based approach for treating other inflammatory disease conditions, including Type 1 diabetes, lupus, or rheumatoid arthritis.

Sources: UCLA, ACS Nano.