New understanding of immune cells could help us fight infection without antibiotics

  • Study reveals how effective immune cells are at controlling Staphylococcus aureus – bacteria that can cause life-threatening infections in humans
  • Research paves the way for the development of new treatments to help the immune system kill bacteria without antibiotics
  • New insight into the immune system’s response to infection is vital as antibiotics become less effective

immune cells

A new understanding of immune cells could help scientists support our own immune system to fight infection without the need for antibiotics.

Scientists from the University of Sheffield examined how immune cells – called neutrophils – respond to bacteria, and the many different strategies they use to kill microbes which can cause harmful infections.

The study, published in the journal Autophagy, revealed how effective neutrophils were at controlling Staphylococcus aureus – bacteria that can cause life-threatening infections in humans.

Dr Simon Johnston, Senior Research Fellow at the University of Sheffield’s Florey Institute and Department of Infection, Immunity and Cardiovascular Disease, said: “A major problem in some Staphylococcal aureus infections is that they can be resistant to antibiotics. This means treating these infections might be very difficult or impossible.

Dr Josie Gibson, who conducted the study, said: “We found that neutrophils are almost perfect at eating and destroying bacteria, but some bacteria were able to escape the neutrophils’ stomach, called the phagosome. The phagosome is where bacteria are normally trapped and killed but escaped bacteria can grow and spread, causing serious infection.

“We know that some immune cells can detect when bacteria escape these phagosomes. One way is using autophagy, a process that evolved to recycle old or broken parts of cells.”

When autophagy is used to control infection it is called xenophagy or ‘eating others’. The Sheffield team found that escaped bacteria were being attacked via xenophagy by a protein called p62/SQSTM1 (p62). When the scientists reduced the amount of p62 in immune cells and made a p62 protein that could not activate autophagy, the infection was made worse.

Dr Johnston said: “Our research suggests that xenophagy was needed by neutrophils to control escaped bacteria.”

“We hope this research will pave the way for the development of new treatments that support the immune system, and don’t rely on antibiotics, to kill bacteria.

“Antibiotic resistance is an increasing problem and threatens our ability to perform many medical procedures such as surgery or cancer treatments because of the threat of uncontrolled infection.”

Additional information

The findings are published in the journal Autophagy entitled: Neutrophils use selective autophagy receptor Sqstm1/p62 to target Staphylococcus aureus for degradation in vivo in zebrafish

The University of Sheffield

With almost 29,000 of the brightest students from over 140 countries, learning alongside over 1,200 of the best academics from across the globe, the University of Sheffield is one of the world’s leading universities.

A member of the UK’s prestigious Russell Group of leading research-led institutions, Sheffield offers world-class teaching and research excellence across a wide range of disciplines.

Unified by the power of discovery and understanding, staff and students at the university are committed to finding new ways to transform the world we live in.

Sheffield is the only university to feature in The Sunday Times 100 Best Not-For-Profit Organisations to Work For 2018 and for the last eight years has been ranked in the top five UK universities for Student Satisfaction by Times Higher Education.

Sheffield has six Nobel Prize winners among former staff and students and its alumni go on to hold positions of great responsibility and influence all over the world, making significant contributions in their chosen fields.

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Contact

For further information please contact:

Amy Huxtable
Media Relations Officer
The University of Sheffield
0114 222 9859
a.l.huxtable@sheffield.ac.uk