by Catriona Nguyen-Robertson
RSV Science Communications
On the 13th of December, Her Excellency the Honourable Linda Dessau AC, Governor of Victoria, presented the Royal Society of Victoria’s Medal for Excellence in Scientific Research to Professors Anthony Burkitt and Jamie Rossjohn (en route to induct the new Victorian Premier and Cabinet!).
Professor Burkitt leads a consortium of Australian universities and institutes to develop a bionic eye and technology, Bionic Vision Australia, and Professor Rossjohn is a leader in the field of immunology, in his quest to better understand how the immune system works and can be manipulated to address disease. The RSV Research Medal awarded to two leaders in their fields recognises both their research career achievements as well as their impact in the scientific community through mentorship and public engagement.
Vision Restoration through Medical Bionics
2018 RSV Medallist for Excellence in Scientific Research: Professor Anthony Burkitt, Research Director of Bionic Vision Australia and Professor of Engineering at the University of Melbourne, Department of Biomedical Engineering
Professor Burkitt grew up among a family of doctors, but decided that medicine wasn’t the right path for him, wanting to do something “with much more direct input” on people’s lives. As a student, he loved physics and mathematics, and now draws upon these as an interdisciplinary scientist with a “clear vision to work towards a single goal”: to develop the bionic eye.
Australia played a significant role in the development of bionic technology. Telelectronics was Australia’s first successful high-tech medical electronics company that pioneered the implantation of medical devices into the body safely in the context of heart pacemakers. Based on that early work, Professor Graeme Clark invented the cochlear implant that coverts sound into electrical impulses to be picked up by sensory nerves in the ear, thereby restoring hearing. It was these foundations that Professor Burkitt built upon to successfully restore vision with a bionic eye.
The retina contains photoreceptors (rods and cones) and nerves to provide vision. Photoreceptors transform light into electrical signals that are sent to the brain via the optic nerve. If the photoreceptors die, a person is left with no visual percept, however, the surviving nerve cells can be targeted to restore their sight. Professor Burkitt and his team built a wearable camera (embedded into glasses) that can bypass the defunct photoreceptors: the camera records images, which are processed, then sent to implanted platinum electrodes in the retina that transmit electrical signals for the surviving nerve cells to receive and send on to the optic nerve. This device provides patients with a pixelated vision of the world based on the number of electrodes implanted, and is only becoming clearer and more detailed as the technology and software is developed. The three patients who received this device in the first trial became a part of the research team, providing direct understanding to what patients could see and what could be improved.
In the transition to a less invasive alternative, Professor Burkitt collaborated with a large team to develop a brain-machine interface with enhanced biocompatibility and high-resolution functionality that is implanted with minimal trauma [i]. Neural implants are often connected to the brain by sitting either on the brain’s surface or being placed in the cortex, while his team places the implant in blood vessels of the brain. The technologies developed by Bionic Vision Australia are now being commercialised and are undergoing patient trials. With both the bionic eye and this next-generation brain-computer interface, Professor Burkitt’s research will not only provide great benefit to vision-impaired patients, but to a range of applications that use brain-computer interface technology.
Visualising Immunity: Knowing Your MAITs
2018 RSV Medallist for Excellence in Scientific Research: Professor Jamie Rossjohn, Head of the Infection and Immunity Program, Monash Biomedicine Discovery Institute
During his high school years, Professor Rossjohn developed a liking for biology and chemistry, which was nurtured by teachers and mentors. Since 2002, he has undertaken independent research to better understand the immune system. Following on from Professor Burkitt’s talk, he agreed that the eye is a “powerful sensor”, however it can “only see so much”. Professor Rossjohn explores what is invisible to the naked eye, requiring the Australian Synchrotron, a “football field-sized microscope” to see the fundamental, molecular mechanisms of the immune system. The Synchrotron produces intense beams of light that are more than a million times brighter than the sun, which Professor Rossjohn uses to explore structural biology – the shapes and behaviours of molecules and their interactions with cells – and produce images of these complex processes.
Central to the immune system are T cells, which kill infected cells to limit the spread of an infection, or coordinate and provide help to other immune cells. During an infection, proteins pick up parts of bacteria and viruses and display them to T cells as a beacon (T cells will not interact with the bacteria or viruses otherwise). Most T cells recognise bacterial or viral signatures when presented with the protein MHC, however Professor Rossjohn focuses on the more ‘unconventional’ T cells that require other proteins. One such group of T cells are termed ‘mucosal-associated invariant T’ (MAIT) cells, which see bacterial components presented by an MHC-related (MR1) protein instead.
MAIT cells account for a significant proportion of T cells, especially in mucosal areas such as the gut and liver, and are one of the faster groups of cells that respond to infection. For a long time, they were known to be activated to kill bacteria and yeast, but the exact signatures from bacteria and yeast they recognise were unknown. Dr Lars Kjer-Nielsen, a postdoctoral researcher in Professor Jim McCluskey’s Laboratory at the University of Melbourne, observed that when growing MAIT cells in vitro (tissue culture), even the cells growing in the absence of bacteria were entering into a state of activation, indicating that a component of the tissue culture media (containing nutrients for cells to survive and grow) could activate MAIT cells. He identified the activating compound as vitamin B derivatives, made during the production of vitamin B2 [ii]. In collaboration with the McCluskey group, Professor Rossjohn’s team determined the structure of MR1 in complex with vitamin B derivatives to learn how they potently activate MAIT cells. Importantly, the pathways that produce these metabolites are unique to bacteria (our bodies can’t make these compounds), making them an ideal target for T cells, however we do consume them in Berocca vitamin tablets, Victoria Bitters beer, Vegemite, and Voltaren anti-inflammatory drugs. Professor Rossjohn is further investigating the role of MAIT cells in the immune system, and his work to date has shown promise for being able to manipulate these cells in disease.