Medical Research: What is the background for this study? What are the main findings?
Dr. McCusker: When the body is exposed to new substances, the immune system must evaluate the “threat” and choose the type of response that will best protect the host. Allergies and allergic asthma develop after the response to “allergens” follows the TH2-type inflammatory pathway instead of the non-inflammatory tolerant pathway. Evidence suggests that there is some plasticity in this “choice” and thus it may be possible to influence the immune response to preferentially choose the tolerant pathway when exposed to allergens. We therefore treated very young mice to a molecule designed to inhibit activation of the TH2 pathway.
We showed that this early treatment resulted in long-lasting protection from the development of allergies. Instead of allergic responses, vaccinated animals developed tolerant responses to allergens and did not show any signs of allergies or asthma. Importantly, while the influence of the treatment was long-lasting, the molecule itself is rapidly removed from the system.
Medical Research: What should clinicians and patients take away from your report?
Dr. McCusker: Allergy development results from a combination of genetic and environmental factors. Manipulation of the immune system to promote tolerance early in life may result in lifelong protection from allergies as the immune system “ can learn” to be tolerant of allergens. This study we showed that early inhibition of the TH2-type pathway resulted in immune-education towards tolerance that persisted through adulthood. Thus a vaccine that prevents development of allergies is a very real possibility.
Medical Research: What recommendations do you have for future research as a result of this study?
Dr. McCusker: This research in animals, coupled with a recent clinical trial in infants shows that infant immune responses can be influenced to develop in the best possible adaptive manner to provide balance between protection from infection and tolerance. The timing of introduction of oral and inhaled allergens is critical for promoting tolerance. Studies are needed to further evaluate the elements essential for promoting this homeostasis to develop strategies aimed at reducing the frequency of allergies and asthma in children.
MedicalResearch.com Interview with: Dr. Christine McCusker MD (2015). Scientists Get Closer To A Vaccine Against Allergies