Imagine a future where you simply introduce a “Trojan horse” into your body to turn off your allergic asthma, food allergy or even an autoimmune condition like celiac disease over the long term.
That’s the treatment Stephen Miller envisions, complete with nanoparticles that contain triggers that previously may have made you develop symptoms such as asthmatic night cough, the hives and wheezing of food allergy, or celiac stomach bloat and rash.
The goal is for the nanoparticle and its cargo to fool your immune system into not responding, says Miller, a professor at Northwestern University’s Feinberg School of Medicine in Chicago and the senior author of a study that was published in April in the Proceedings of the National Academy of Sciences.
“The study was based on the notion that autoimmune diseases are caused by a certain kind of T-cell and allergies are caused by another kind – and if the treatment works for one, it could work for the other,” said Miller, who holds the medical school’s Judy Gugenheim research chair in microbiology and immunology. “It’s exciting. Where other drugs are regulating symptoms, we’re targeting the cause of the disease.”
Although the Trojan horse method has previously been tested in pre-clinical animal trials to treat autoimmune conditions, this marks the first time it has been used in the search for new ways to treat allergic and asthmatic diseases.
The study revolved around injecting nanoparticles that contained an egg protein allergen into sensitized mice to see if it controlled their allergic airway reaction – the closest animal model to asthma in humans. It worked because the animal immune systems weren’t concerned with what they saw as harmless debris, thus allowing the nanoparticles and their hidden triggers to be consumed by a macrophage, which Miller describes as a “vacuum-cleaner cell.”
“This cell introduces the allergen or antigen to the immune system in a way that says, ‘No worries, this belongs here,’” he explained.
Now, the nanoparticles, which are composed of a biodegradable, FDA-approved polymer that is already used for absorbable sutures for surgery, are being tested yet again in mice, this time with peanut protein as their hidden cargo.
“Our feeling is that we have a universal (nanoparticle) and can switch the antigen inside, no matter if it’s peanut, ragweed, pet dander, cockroach or whatever,” Miller said. “In theory, at least, there is the potential of treating a whole host of autoimmune diseases, allergies and asthma – and even organ transplant rejection.”
“Now, what we need to determine is whether or not delivering antigens or allergens into humans in this manner is both safe and effective in stopping the progression of a specific condition.”
To that end, Miller is looking forward to a small clinical trial set to begin next year that involves patients with celiac disease, an autoimmune condition that occurs because the immune system sees gluten, a protein in wheat, barley and rye products as an enemy. There are a multitude of symptoms, including diarrhea, anemia and osteoporosis, and the only treatment right now is to eliminate gluten from one’s diet.
“If the celiac disease trial works and patients are able in ingest gluten without any problem, this could be a game breaker,” he said. “We could finally have an answer to lung and food allergies, to ragweed, pet dander, cockroaches and whatever else.”