The role of OX40 ligand/OX40 axis signalling in atopic dermatitis

Lay Summary Atopic dermatitis (AD) (also known as atopic eczema) is a common skin disease caused by inflammation, and affects 2–3 of every 10 people worldwide. AD affects people of all ages and can cause a range of symptoms, including dry thickened skin, itchiness, rashes and pain. Despite the recent addition of new targeted treatment options, there is still a need for new treatments for people with moderate-to-severe AD. New drugs are being studied that target two important signalling molecules in the immune system, called OX40 ligand (OX40L) and OX40. OX40L and OX40 bind together to continue the cycle of immune system activation, leading to increasing symptoms of AD. Blocking the OX40L and OX40 interaction may ease or stop symptoms of AD. This review outlines what is currently known about the causes of AD, including the role played by the immune system and specifically the role of OX40L and OX40. We also highlight the development of new treatments that target the OX40L and OX40 interaction to treat AD, and suggest what the future may hold for managing AD.