Allergy journey sparks BME graduate student’s research

Ian McKnight’s journey to becoming a scientist started at age two with a near-fatal allergic reaction to a peanut butter and banana sandwich.  

Since then, learning to manage multiple allergies has become a staple of his daily life.  

“It’s always been interesting and frustrating to me that while there are treatments for allergies, like antihistamines and allergy shots, there’s nothing that can permanently reverse or fully eliminate allergic responses,” he said.  

Now in his third year of the Johns Hopkins Biomedical Engineering PhD program, McKnight is researching the biological mechanisms underlying allergies, with the goal of developing new therapeutics to provide long-term relief to fellow allergy sufferers. 

Allergic reactions occur when the immune system tries to mount a defense against a typically harmless substance, such as pollen or peanuts. Roughly 100 million people in the US have allergies each year, according to the Asthma and Allergy Foundation of America (AAFA). Scientists are still trying to uncover not only why allergies develop, but also why some people are more susceptible to them. 

McKnight’s research explores potential immunotherapy strategies that could dial down the immune system’s overreaction to allergens. The goal is to contribute to a type of tolerogenic, or “inverse,” vaccine for allergies; instead of training the body to activate and attack a threat – as the flu vaccine does – it would teach the immune system to recognize allergens are harmless and simply ignore them.  

“The body thinks allergens are something it’s supposed to fight when it’s not,” said McKnight, who is working with advisors Scott Wilson, assistant professor of biomedical engineering, and Stephane Lajoie, assistant professor of otolaryngology-head and neck surgery, on the research. “We’re aiming to create treatments that could induce long-lived tolerance to a specific allergen without shutting down the rest of the immune system.”  

A lifelong soccer fan, McKnight said he is taking multiple shots on goal at identifying the most effective strategy for long-term allergy treatment. One promising target is the liver, which helps regulate the immune system and filters every substance that gets into our bloodstream. McKnight is exploring ways to take advantage of the liver’s special tolerogenic environment in order to reprogram the immune system to no longer respond to an allergen. His research is laying the groundwork for a polymer-based treatment that delivers a small amount of an allergen directly to the liver, aiming to induce a body-wide tolerance.  

In another project, McKnight is studying how the epithelial cells that line the airway contribute to the allergic process. Understanding how inhaled allergens, like house dust mites, infiltrate these protective cells could open the door for therapies that reprogram the cells to block allergens from passing through, he said.  

For McKnight, this research is more than a scientific quest: It’s personal. Though allergies are mild and little more than an inconvenience for many, for him and others, they can be life-threatening. He hopes that future treatments such as those he is contributing to will someday provide a sense of normalcy and security to people living with allergies.  

Originally from Parkersburg, West Virginia, McKnight earned an undergraduate degree at Marshall University as part of the university’s first biomedical engineering cohort.  

“As someone coming from rural Appalachia, I didn’t have STEM extracurriculars growing up like many of my peers,” he said. “Marshall was really my first glimpse into the science world and solidified my interest in doing research.”  

When he was searching for PhD programs after graduation, Johns Hopkins immediately stood out. At Hopkins, he says he has found community and an environment that supports collaborations, even among labs doing very different research.  

And while he is considering a career in academia, McKnight for now will continue work as both a researcher and science mentor. He participates in outreach activities like Letters to a Pre-Scientist (LPS), a pen pal program that pairs young students with professional scientists to inspire and nurture their interest in science.  

“In addition to improving the lives of people with allergies, I’m passionate about bringing knowledge back to Appalachia and other places where young people haven’t really had an equal experience with STEM,” said McKnight.