Edinburgh Infectious Diseases
EID logo 2019

New insight into how the body ‘gobbles up’ asthma-inducing cells

Researchers in the MRC Centre for Inflammation Research look into potential novel therapy for treating allergy-induced lung diseases.

Eosinophil with red blood cells

Allergy-induced lung diseases, such as asthma, occur when the immune system does not respond properly to otherwise-harmless substances found in the environment (e.g. pollen).

The resulting inflammation causes on average three deaths every day in the UK, and with 5.4 million people currently being treated for asthma in the UK it is very much still a prevalent problem.

It has been previously determined that a certain type of white blood cell within the human immune system – called an ‘eosinophil’ (above) –  plays a role in how severe allergy-induced lung diseases are.

Usually, when an allergic reaction is subsiding the eosinophils undergo ‘self-destruct’, and are subsequently ‘eaten’ and removed from the body by surrounding cells.

However, it has also been shown that the ability of the surrounding cells to eat dead eosinophils is reduced in people with asthma. What is currently unknown is whether this reduced ability directly contributes to the severity of illness.

Recent experiments led by  Dr Jennifer Felton, Dr Chris Lucas and Professor Adriano Rossi at the MRC Centre for Inflammation Research have shown that a molecule called ‘Mer’ is important for eating dead eosinophils.

Dr Lucas says:

"High-dose steroid treatment is frequently used in poorly controlled asthma. However, this causes multiple side effects, and a significant proportion of asthmatic individuals are steroid-resistant. Therefore, identifying new targets that ‘switch off’ allergic inflammation is key to developing new therapies for diseases such as asthma."

In the team’s study, a low amount or complete absence of Mer led to both a reduced ability to eat dead eosinophils and an inability to ‘switch off’ allergic inflammation in the lungs in a timely fashion, leading to increased inflammation and worse outcomes.

Finding a way for the immune system to eat more dead eosinophils is therefore a potential novel therapeutic strategy to treat asthma and other allergic diseases.

Dr Lucas concludes:

"The next step will be to see if boosting the levels of the molecule ‘Mer’ leads to the termination of allergic inflammation; if so this strategy could be used to develop new treatments for asthma and allergy with a potential for fewer side effects"


Published article in the Journal of Allergy and Clinical Immunology (PubMed website)

Prof Adriano Rossi – Research Profile

Dr Chris Lucas – Edinburgh Research Explorer