Study of 'Big Eaters' could lead to better asthma treatments

A new study into the role of a particular immune cell in the lungs could lead to better treatments for the 5 million people in the UK affected by asthma.

Scientists from the University of Southampton's School of Medicine will study the role of macrophages (literally 'big-eaters' in Greek) in the lungs of people with asthma and examine how they affect the airway narrowing that can worsen asthma symptoms.

Macrophages are the predominant type of white cells found in the lungs and their function is to clear any particulate matter, bacteria or damaged cells that may be present in the airway.

Asthma is characterised by damage to the cells lining the airway and the act of removing these particular damaged cells can cause the macrophages to switch to working in a negative rather than a positive way. They start releasing chemicals that recruit and activate other inflammatory cells to the lung, which can cause further damage to the airway.

At the same time, the macrophages also release growth factors that can re-model the airways leading to narrowing and increased twitchiness. What is not understood is why macrophages from the lungs of people with asthma release these inflammatory and growth factors, while macrophages from those without asthma do not.

Dr Karl Staples and Professor Ratko Djukanovic, from the University's School of Medicine, will study macrophages isolated from the lungs of people both with and without asthma, to discover what inflammatory and growth factors are released from these cells when they 'eat' damaged cells. They will also be looking at the ways in which the alternative activation status of macrophages in asthma may be inhibited.

The research, funded by the charity Asthma UK, may uncover new signalling mechanisms that can be targeted using drug therapy, leading to better treatments for asthma.

Dr Staples comments: "Current asthma therapies provide symptom relief and disease control and are not cures. As a result, asthmatics are on constant medication which can impact on their lifestyle. However, these treatments do not seem to be effective in those patients with more severe disease."

Professor Djukanovic adds: "By focusing the spotlight on these important inflammatory cells, which despite being the major immune cell present in the lungs, have long been neglected in the study of asthma, we hope to clarify novel drug targets that could lead to more effective treatments."

According to Asthma UK 5.2m people in the UK are currently receiving treatment for asthma, including 1.1m children, and there is a person with asthma in one in five households in the UK.