Infection inspection

Scientists at Sydney's Centenary Institute in Australia have filmed an immune cell becoming infected by a parasite and followed the infection as it begins to spread throughout the body.

Prof Wolfgang Weninger, head of the Immune Imaging programme at the Centenary Institute, said that the filming was made possible using high-powered multi-photon microscopy, which allows cells to be viewed in real-time.

'Using multi-photon microscopy, we studied dendritic cells in the skin. Under normal conditions we found the cells in the epidermis (top layer) were static, whereas in the dermis (second layer) they were very active, moving around as though seeking out pathogens,' explained Prof Weninger. 'Once we established this, it was fascinating to introduce the Leishmania infection and watch as the parasite was picked up by the cells and the process by which it began to spread throughout the body.'

Leishmaniasis affects up to 12 million people in parts of Africa, the Middle East and South America. The disease causes skin sores and can affect internal organs such as the spleen, liver and bone marrow. If left untreated, it can be fatal.

The ability to visually follow a pathogen on its journey through the immune cells provides critical insight for future vaccine design and has potential to improve current vaccinations.

'We now have a general idea of how pathogens are recognised by the immune system and which cells are involved,' said Prof Weninger. 'This means we can look at identifying the molecules responsible for the uptake of Leishmania infection and these molecules could become vaccine targets. Additionally, we can investigate the immune responses of other infections, which could lead to better vaccines.'