An accidental discovery by Melbourne researchers has revealed the purpose of ‘mystery’ immune cells in the gut, shown how our immune system interacts with the complex bacteria ecology found there, and opened new paths for drug discovery.
Our guts, lungs and mouths are lined with mysterious immune cells that make up to 10 per cent of the T cells in our immune system. These immune cells, known as mucosal-associated invariant T cells (MAITs), detect reactive intermediates in the synthesis of vitamin B2 (riboflavin) that is made by many invasive bacteria and fungi.
Cells involved in the first line of our immune defence have been located where they never have been found before—a discovery that could provide insight into diseases like psoriasis and other auto-immune conditions of the skin.
While researchers have known about these cells, called gamma delta T cells in the epidermis or top layer of skin for more than 20 years, this is the first time their presence has been detected in the next layer of skin down, the dermis.
Wolfgang Weninger, who led the study at Sydney’s Centenary Institute, says that gamma delta T cells are of particular interest because they produce a protein thought to be the ‘first responder’ when intruders are detected by the immune system.