16 Dec 2020

A study, funded by the LEO Foundation, has identified the factor that triggers eczema caused by Staphylococcus. The study is a breakthrough of our understanding of the common skin condition.

The discovery of a missing link by an international team led by University of Manchester scientists could lead to new treatments of eczema – a sometimes debilitating skin condition which affects 20-30% of children.

Principal investigators Dr Peter Arkwright and Dr Joanne Pennock identify ‘second immunoglobulin-binding protein’ – or ‘Sbi’ – as a unique trigger of eczema by Staphylococcus aureus – also known as golden Staph.

In a paper published in the prestigious Journal of Allergy and Clinical Immunology, they show that the bacterial species is unique in producing Sbi which triggers allergic inflammation in the skin.

Sbi triggers eczema

The study, funded by the LEO Foundation, for first time identifies Sbi as the molecule that induces rapid release of Interleukin-33, a key component of the immune response in childhood eczema.

“Our study shows beyond any doubt that Sbi is the dominant infective trigger of eczema and that is incredibly exciting,” said Dr Arkwright.

“Scientists have long known that Staphylococcus aureus is the dominant pathogen on human skin, causing the majority of skin and soft tissue infections worldwide. But only now do we understand that it is only because it expresses predominant virulence factor Sbi, that allergic eczema is triggered. There have been lots of dead ends and false leads, but after many years, we’ve finally found the missing link. We are extremely grateful to Professors Hiroshi Matsuda and Akane Tanaka for their collaboration, which contributed valuable results to this project.”

Results can be used to discover treatments for eczema

The search for the missing link involved mouse eczema model studies led by Tokyo University of Agriculture and Technology, and bench work on cells and human skin tissue at Manchester.

The scientists also studied six other species of staphylococci, as well as the common Group A strep which causes tonsillitis and scarlet fever, but none generated allergic responses.

In each part of the study, the results pointed to Sbi – first discovered in 1998 – as the trigger.

Dr Pennock, from The University of Manchester said:

“Our primary aim was to understand why Staphylococcus aureus is so uniquely associated with allergic reactions in skin. The precise mechanism that drives the allergic pathology in eczema patients has been a mystery, until now. Staphylococcus aureus expresses many virulence factors so finding the right protein was a challenge. We have shown that only golden Staph that expresses Sbi is capable of causing the allergic skin response. Now our aim is to learn more about Sbi in order to lay the groundwork for future non-steroid treatments. We are very grateful to the LEO Foundation for continuing to fund this exciting work. ‘’

The paper Staphylococcus aureus Second Immunoglobulin-Binding Protein drives atopic 2 dermatitis via IL-33 is published in the Journal of Allergy and Clinical Immunology.