A new treatment option

Historically, most of the approaches to treating psoriasis have focused on inhibiting the actions of pro-inflammatory immune cells, i.e. the cells causing the inflammatory response. Now a remarkable study from the University of Vienna has suggested that it may instead be possible to restore the function of those cells which normally act to prevent inflammation. The researchers focused on the role of regulatory T cells (Treg cells) in chronic inflammatory skin diseases such as psoriasis. Treg cells are important components of the body's immune system that specialise in preventing excessive immune responses and thus inflammation.

It is already known that these cells lose their regulatory function in chronic skin inflammation, causing the immune response to become uncontrolled and the disease to progress. For the first time researchers have now decoded the exact cellular mechanism behind this loss of anti-inflammatory function. The key problem seems to lie with the function of an enzyme called SSAT, which regulates the balance between anti-inflammatory and pro-inflammatory immune cells. When SSAT is produced in increased amounts in Treg cells, they lose their anti-inflammatory function and begin to produce pro-inflammatory substances instead.

Having identified the faulty mechanism, the researchers then used a mouse-model with psoriasis-like skin inflammation, to establish what happens if they inhibit SSAT. They found that in doing so, they could restore the function of Treg cells and break the cycle of inflammation in the psoriasis plaques. This clearly opens the way to the development of new drugs which are specific SSAT inhibitors and which can help restore the normal anti-inflammatory response.  Moreover, since other chronic inflammatory diseases of the skin are characterised by impaired immune regulation, this approach has applications beyond psoriasis.

Comment:
In this study researchers focused on developing a new approach to the treatment of psoriasis which, rather than blocking the activities of cells known to cause inflammation, instead focused on restoring the function of cells which normally prevent inflammation. It is a novel and exciting approach which, although in its early stages, could transform the treatment of psoriasis and other chronic inflammatory conditions.  

Reference:
Neuwirth T, Malzl D, Knapp K, et al. The polyamine-regulating enzyme SSAT1 impairs tissue regulatory T cell function in chronic cutaneous inflammation. Immunity. 2025; Volume 58, Issue 3, 632-647