Researchers Pinpoint Novel Asthma Treatment Target

By comparing healthy and asthmatic lung cells post-infection, Imperial College London researchers believe they have discovered a new treatment target for asthma.

With 235 million sufferers worldwide, asthma is the most common non-communicable disease among children. In the UK alone, where the study took place, 5.4 million people currently receive treatment for asthma, a statement pointed out.

"Asthma attacks are still a huge health care problem. Existing medication containing inhaled steroids, are highly effective at controlling regular asthma symptoms, but during an attack the symptoms worsen and can lead to the patient going to hospital,” commented Sebastian Johnston of the National Heart and Lung Institute at Imperial College London and a joint lead author of the research.

For their study published in Science Translational Medicine, researchers gathered cells from both healthy and asthmatic lungs. From there, investigators infected their lungs with a rhinovirus, a virus that commonly induces exacerbations in asthmatics, and measured their interleukin-25 (IL-25) levels.

When infected with a rhinovirus, the body produces IL-25 which catalyzes the creation of type-2 cytokines. Type-2 cytokines, which then buildup, leads to a type-2 immune response. Investigators believe blocking IL-25 production could prevent the type-2 cytokine buildup, resulting in a more effective therapy.

Compared to healthy lungs, asthmatics were found to produce ten times more IL-25 after infection.

“Asthmatic epithelial cells have an increased intrinsic capacity for expression of a pro—type 2 cytokine in response to a viral infection, and IL-25 is a key mediator of RV-induced exacerbations of pulmonary inflammation,” the authors wrote.

To gauge IL-25 prevalence directly from the airways, the investigators also took nasal secretions from the participants. In doing so, the writers noted asthmatics also had a larger presence of IL-25 in their secretions.

“Our research has shown for the first time that the cells that line the airways of asthmatics are more prone to producing a small molecule called IL-25, which then appears to trigger a chain of events that causes attacks,” said Nathan Bartlett, an Honorary Lecturer at the National Heart and Lung Institute at Imperial College London and another joint lead author to the study. “By targeting this molecule at the top of the cascade, we could potentially discover a much-needed new treatment to control this potentially life-threatening reaction in asthma sufferers."