29 Apr 2016
Celebrating Day of Immunology with new research
Since 2009, Victoria has celebrated the International Day of Immunology, but has demonstrated world-leading expertise in this field for decades.
The state’s immunology ‘brain trust’ continues to be at the forefront of discoveries unravelling the mystery that is the immune system.
Here at the Doherty Institute, a joint venture between The University of Melbourne and Royal Melbourne Hospital, researchers are working feverishly to write the instruction manual for the immune system in order to develop more effective vaccines, new therapies and drugs, and to better understand its mechanics.
Here are three recent pieces of research that not only highlight the calibre of immunologists at the Doherty Institute, but also the incredible collaborations across different universities and institutes.
Why do natural killer cells discriminate between healthy or diseased cells?
University of Melbourne Professor Andrew Brooks researches natural killer cells and how they discriminate between healthy or diseased cells.
“Natural killer cells use a large number of receptors, each of which come in a many ‘flavours’ and recognise a set of proteins, also coming in thousands of different ‘flavours’,” Professor Brooks explained.
“This variation of flavours creates a complex array where the interaction strength differs – it’s essentially a matrix, which we now have the keys to unlock."
The strength of the interaction between the receptors and the proteins is important because it impacts the way in which the immune system fights different diseases.
“In the case of acute myeloid leukaemia, there is evidence that suggests strong interactions actually prevent killing of the leukemia,” he said.
“This information is useful because you could select bone marrow donors with natural killer cell genes that give a weak interaction, which would provide a better outcome for patients with leukemia.”
Researchers from Monash University, Professor Jamie Rossjohn and Dr Julian Vivian, were key collaborators on this work, which was recently published in the Journal for Experimental Medicine.
The flashing ‘beacon’ that protects us from infection
White blood cells are in abundance and constantly circulate through the body, but are quite tightly regulated and only turn on (or get ‘activated’) when they need to be.
University of Melbourne researchers Professor Jose Villadangos and Dr Hamish McWilliam have identified how a specific molecule (MR1) activates a very common type of white blood cell (MAIT cells).
“We found that MR1 activates these white blood cells by acting like an alarm system. All of the body’s cells have this alarm and when there is an infecting bacteria nearby it turns on, alerting the white blood cell that it needs to start an immune response,” Dr McWilliam said.
“It does this by grabbing the bacteria’s waste products, then holding them outside the cell, acting like a flashing alarm. White blood cells come by and recognise MR1 holding the telltale signs of bacteria.
“This discovery has far-reaching implications - by understanding MR1, we could harness those white blood cells and turn on the alarm at the right time, prompting an immune response.”
Dr McWilliam and Professor Villadangos collaborated with the laboratories of University of Melbourne Professor Jim McCluskey and Professor Jamie Rossjohn from Monash University for this study, which was recently published in Nature Immunology.
Are lipid antigens the key to better vaccines?
University of Melbourne researchers Dr Adam Ulrich and Professor Dale Godfrey are interested in how the immune system recognises foreign particles, also known as antigens. Their research looks at a particular type of antigens called lipids.
There isn’t much known about how the immune system recognises lipid antigens. A lot of the understanding of the immune system is about protein-based antigens, which is what goes into vaccines.
“In our latest study, we identified new subsets of T cells that can recognise lipid antigens,” Dr Ulrich said.
T cells are essential in guarding the immune system. Their role is to hunt down and fight infection.
“The receptors that this new subset of T cells express on the cell surface that mediate the recognition of lipid antigens were very distinct to other T cells that have previously been found to recognise lipid antigens.
“This research is part of the building block of the human immune system. Once we understand that better, we can then start to think about what we can do with these cells and the recognition events.”
In collaboration with Professor Jamie Rossjohn from Monash University, this research was published in Nature Communications.