Skin cells form quick defence in body: Study

Scientists claim to have discovered that certain skin cells can recognise viruses and
respond right away, a finding which could improve treatment of viral skin infections.

According to them, the work identifies previously unrecognised first-line defence mechanisms important in barrier locations such as the skin and the gut, often used as portals of entry by viruses.

The findings entail the function of the cells that trigger the initial immune response to viral infection, known as dendritic cells.

"Dendritic cells are like police patrolling our blood and tissues for anything unusual. There are many different types of them, so we wanted to examine how they differ in
their function," said Dr Sammy Bedoui of Melbourne University, who led an international team.

Using an animal model of skin infection with the cold sore virus, the scientists examined two aspects of anti-viral immune responses by studying the cells involved in the initial
stimulation of the immune response, and cells that remember past infections to boost the response after reinfection.

The team showed for the first time that a particular type of dendritic cells was responsible for triggering the immune response. These cells do this by presenting virus
particles to Killer T cells, which triggers a cascade of immune responses to tackle infection.

"Because the cells are located at the site of infection, they can respond instantly, much faster than other immune cells that have to travel via the blood to the site. This debunks previous thought that immunity by T cells only occurs at longer distances throughout the body," said team member Dr Thomas Gebhardt.

The findings are published in the 'Nature Immunology' journal.