Food allergies can be a life-threatening situation, but new research shows the danger could be mitigated by changing the body’s immune response. Scientists at Duke Health were able to reprogram the immune system of mice by using nanoparticles to deliver molecules to the lymph nodes that kept the mice from experiencing symptoms from exposure.
The results published in the Journal of Allergy and Clinical Immunology give researchers hope they will be able to do likewise in people so they can avoid the serious consequences of food allergies.
"This study in mice proves the concept of this approach, so tests in humans are not that far off," said Soman N. Abraham, Ph.D. "We are encouraged by these findings, because it's a fairly simple way to reprogram the immune system."
It is estimated that as much as six percent of children and four percent of adults in the U.S. have some form of food allergy with a reaction to peanuts among the most common. Peanut allergies can be deadly so those susceptible need to be extra careful about exposure, especially as it relates to everyday food choices that may have hidden traces of peanuts.
One method of combatting food allergies is to desensitize allergic people by exposing them to their allergens in small doses and gradually increasing the dose as their tolerance grows. It has proven to be effective, but it takes time and there are inherent risks.
For this study, researchers focused on the signaling in the immune system when exposure takes place because previous observations have shown allergic reactions are as a result of an imbalance of messages between cells called cytokines. It is the Th2-type cytokine immune response that is thought to be the driver of the overactive response. Th2 is supposed to work in tandem with Th1 but in an allergic reaction Th2 is produced in greater quantity than Th1.
When the nanoparticles containing Th1 traveled to the lymph nodes they dissolved and delivered their immune balancing force. The mice no longer experienced the allergic response anaphylaxis when exposed to peanuts and the tolerance did not need to be repeated before subsequent exposures.
"The Th1 and Th2 sides of immunity balance each other," said researcher Ashley St. John. "We reasoned that since we know Th2 immunity is over-produced during allergic responses, why not try to skew the immune response back the other direction? By delivering cytokines to the lymph nodes where immune responses are established, we were able to re-educate the immune system that an allergic response is not an appropriate one."