Irish scientists have made a breakthrough which could lead to the development of new therapies to treat the skin condition, psoriasis.

Psoriasis is an inflammatory skin condition, which appears as pink or red raised patches on the skin. These patches, which are known as plaques, have a well-defined edge around them. They also have a scaly surface and can be large or small.

Around 73,000 people in Ireland have the condition, with 9,000 of these suffering from a severe form.

The scientists at Trinity College Dublin (TCD) made an important breakthrough in understanding how the protein, Interleukin-36, plays a key role in switching on the immune system.

Interleukin-36 acts as an ‘immune SOS signal', similar to an intruder alarm in the body, particularly the skin. It switches on when an injury or infections occurs, mobilising the immune system to repair any damage.

This process is called inflammation and it causes the redness and swelling that most people are familiar with if we, for example, bump our head or sprain an ankle.

While inflammation is usually considered a good thing, as it is essential to allow the body to heal and to shut down infection, for some people, including those with psoriasis, Interleukin-36 gets switched on too readily. As a result, those affected experience skin inflammation on an almost continual basis.

Until now, scientists have wondered how Interleukin-36 gets switched on to send out its SOS signal. The team at TCD have discovered the molecules responsible for converting the protein from its harmless form to its destructive form, by removing a small piece of it. They liken this to pulling a pin out of a grenade.

These molecules are called proteases and are overactive in the skin of people with psoriasis. This suggests that the skin condition could be treated in a new way.

Lead researcher, Prof Seamus Martin, described the breakthrough as ‘very exciting'.

"We really hope to develop this approach into a new way of treating psoriasis. This work represents an excellent example of how basic research leads to fundamental breakthroughs in our understanding of how diseases arise. Without such knowledge, it would be very difficult to develop new therapies," he commented.

The research was carried out in TCD's department of genetics and was funded by Science Foundation Ireland. Details are published in the journal, Cell Reports.