Sydney, June 6 (IANS) Scientists have pinpointed the exact molecular 'switch' which spurs T-cells into activating our immune system against the invasion of germs, thanks to the only super microscope of its kind in Australia.

 
 The breakthrough by the University of New South Wales (UNSW) researchers could lead to treatments for a range of conditions from auto-immune diseases to cancer.
 
 Studying a cell protein important in early immune response, the team led by associate professor Katharina Gaus from UNSW used the country's only microscope capable of super-resolution fluorescence to image the protein molecule-by-molecule to reveal the immunity 'switch'.
 
 The technology is a major breakthrough, Gaus said. Currently there are only half a dozen 'super' microscopes in use around the world, the journal Nature Immunology reports.
 
 "Previously you could see T-cells under a microscope but you couldn't see what their individual molecules were doing," Gaus said, according to an UNSW statement.
 
 Using the new microscope, the scientists were able to image molecules as small as 10 nanometres (a nanometre is a billionth of a metre). Gaus said that what the team found overturns the existing understanding of T-cell activation.
 
 "Previously it was thought that T-cell signalling 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 said.
 
 "There is this rolling amplification. The signalling 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," Gaus said.