Using super microscope scientists find body’s immunity “switch”

Posted by Chris Nova

Thanks to a super advanced microscope, medical scientists can finally see what goes on inside of T-cells. What they've seen so far could lead to a new era of medical treatments.

As you may know, T-cells sound the alarm when our immune system needs to go into defensive mode against unwelcome germs and invaders in our bloodstream.

T-Cells are quite important, that's why this is a big discovery, it turns conventional wisdom about T-Cells on its head.

The researchers at the University of New South Wales have identified an exact molecular “switch” that sends T-Cells into action, a breakthrough that might lead to treatments for a list of conditions such as auto-immune diseases and cancer. The findings will be published today in the journal Nature Immunology.

Learning about a cell protein is important in early immune response, the researchers directed by Associate Professor Katharina Gaus from UNSW's Centre for Vascular Research at the Lowy Cancer Research Centre, used Australia's only microscope with super-resolution fluorescence microscopy capabilities to image the protein molecule-by-molecule to uncover the immunity "switch."

The technology is a major breakthrough for science, Dr Gaus said. Presently there are only half a dozen of the "supe"” microscopes in use around the world. Although this discovery could lead to more of them being built in the future.

"Previously you could see T-cells under a microscope but you couldn't see what their individual molecules were doing," Dr Gaus explained.

Using the new mega-powered microscope the scientists were able to get images of molecules as small as 10 nanometers. Dr Gaus said that what the team found flips the existing understanding of T-cell activation upside down and inside out, which is common in science.

"Previously it was thought that T-cell signaling was initiated at the cell surface in molecular clusters that formed around the activated receptor. In fact, what happens is that small membrane-enclosed sacks called vesicles inside the cell travel to the receptor, pick up the signal and then leave again."

Gaus believes the discovery explains how the immune response could occur so quickly.

"There is this rolling amplification. The signaling station is like a docking port or an airport with vesicles like planes landing and taking off. The process allows a few receptors to activate a cell and then trigger the entire immune response."

PhD candidate David Williamson, whose research was the origin of the paper, said the discovery showed what could be accomplished with the new generation of super-resolution fluorescence microscopes.

"In conventional microscopy, all the target molecules are lit up at once and individual molecules become lost amongst their neighbors – it's like trying to follow a conversation in a crowd where everyone is talking at once," explained Williamson.

"With our microscope we can make the target molecules light up one at a time and precisely determine their location while their neighbors remain dark. This 'role call' of all the target molecules means we can then build a 'super resolution' image of the sample."

The subsequent was to isolate other important proteins to receive a full picture of T-Cell activity and to lengthen the microscope to capture 3-D images with the same unparalleled clarity.

"Being able to see the behavior and function of individual molecules in a live cell is the equivalent of seeing atoms for the first time. It could change the whole concept of molecular and cell biology," he added.