By Stephen Beech
The immune system can be "reprogrammed" to heal the body faster using electrical stimulation, according to new research.
Irish scientists discovered that electrically stimulating "macrophages" - one of the immune systems key players - can "reprogram" them in such a way to reduce inflammation and encourage faster, more effective healing from disease or injury.
The "exciting" breakthrough by a team at Trinity College Dublin has revealed a potentially powerful new therapeutic option.
And work is continuing to improve the process.
The researchers explained that macrophages are a type of white blood cell with several high-profile roles in our immune system.
They patrol around the body, looking out for bugs and viruses, as well as disposing of dead and damaged cells, and stimulating other immune cells - kicking them into gear when and where they are needed.
But their actions can also drive local inflammation in the body, which can sometimes get out of control and become problematic, causing more damage to the body than repair.
The researchers say that it is present in several different diseases, highlighting the need to regulate macrophages to improve patient recovery.
The Trinity team worked with human macrophages isolated from a healthy donor blood samples provided through the Irish Blood Transfusion Board, St James's Hospital.
They stimulated the cells using a custom bioreactor to apply electrical currents and measured what happened.
The scientists discovered that the stimulation caused a shift of macrophages into an anti-inflammatory state that supports faster tissue repair, and a decrease in inflammatory marker activity.
It also triggered an increase in the expression of genes that promote the formation of new blood vessels, associated with tissue repair as new tissues form, and an increase in stem cell recruitment into wounds, which is also associated with tissue repair.
Study first author Dr. Sinead O'Rourke said: "We have known for a very long time that the immune system is vital for repairing damage in our body and that macrophages play a central role in fighting infection and guiding tissue repair.
"As a result, many scientists are exploring ways to 'reprogram' macrophages to encourage faster, more effective healing in disease and to limit the unwanted side-effects that come with overly aggressive inflammation.
"And while there is growing evidence that electrical stimulation may help control how different cells behave during wound healing, very little was known about how it affects human macrophages prior to this work."
Dr. O'Rourke, a Research Fellow in Trinity's School of Biochemistry and Immunology, added: "We are really excited by the findings.
"Not only does this study show for the first time that electrical stimulation can shift human macrophages to suppress inflammation, we have also demonstrated increased ability of macrophages to repair tissue, supporting electrical stimulation as an exciting new therapy to boost the body's own repair processes in a huge range of different injury and disease situations."
The team say their findings, published in the journal Cell Reports Physical Science, are "especially significant" given that the work was performed with human blood cells - showing its effectiveness for real patients.
The researchers pointed out that electrical stimulation is relatively safe and easy in the scheme of therapeutic options, and the outcomes should be applicable to a wide range of scenarios.
Study co-leader Professor Michael Monaghan, from Trinity's School of Engineering, said: "Among the future steps are to explore more advanced regimes of electrical stimulation to generate more precise and prolonged effects on inflammatory cells and to explore new materials and modalities of delivering electric fields."
He added: "This concept has yielded compelling effects in vitro and has huge potential in a wide range of inflammatory diseases."