One of the enabling forces behind the tissue-resident memory T cell (TRM cells) discoveries has been the purchase of two, two-photon microscopes.
“The benefit of two-photon microscopy is that it uses a powerful laser that allows you to image very deep into the tissue,” explains University of Melbourne Professor Scott Mueller, who has pioneered the technology at the Doherty Institute over the last five years.
“So not only can you see much further into tissues than if you were using a regular microscope, but you can also see live tissues and pathogens, and watch the events as they are unfolding.”
Professor Mueller, with University of Melbourne Professor Bill Heath, were the first researchers globally to image TRM cells in this way to understand their role. Along with other researchers at the Doherty Institute, they are continuing to use the technology in relation to cancer and malaria, and even in a neuro-immune context, that is how nerves change the way the immune cells work.
“We’ve been able to show that even after the pathogen has gone, the TRM cells continue to migrate around the tissue looking for the pathogen to come back. Some of them are just at the surface of the skin for instance, others are in various tissues all around the body,” says Professor Mueller.
“It’s taught us how these immune cells do their job, which allows us to begin to think of new ways in which we can boost the immune response or come up with drugs to target different pathogens.”
In future, Professor Mueller hopes to establish a three-photon microscope, which would allow researchers to peer much deeper into tissues to see immune cells and pathogen components in areas of the body never imaged before.