Cancer researchers ‘switch on’ Natural Killer cells to fight cancer Posted on June 8, 2016February 25, 2018 by Carly du Toit Walter and Eliza Hall Institute (WEHI) researchers, led by Dr Sandra Nicholson and Dr Nicholas Huntington, together with colleagues from the Queensland Institute of Medical Research (QIMR), are investigating ways to ‘switch on’ our Natural Killer (NK) cells to fight cancer. The researchers identified a protein ‘brake’ within Natural Killer cells that controls their ability to destroy their target tumour cells. “Natural Killer cells exist to detect and then destroy any deviant cells in our bodies before those cells go on to develop into tumours or before infection spreads,” Dr Nicholson said. “Natural Killer cells are a key part of our immune system they work by locating other cells posing a danger to health either because they are infected or because they are becoming a cancer cell,” she continued. Our bodies are constantly and successfully fighting off the development of cells that lead to tumours – but when there is disruption to this process cancer is free to develop. In their paper published in Nature Immunology, they showed that when the brake was removed in an experimental model, the NK cells were better able to protect the body against metastatic melanoma. Natural Killer cells rely on a growth factor called Interleukin 15 (IL15) to activate. Dr Nicholson and Dr Huntington’s research has shown that an inhibitor protein made inside the Natural Killer cells limits the ability of the NK cell to respond to IL15 and therefore kill cancer cells. By identifying for the first time how this protein inhibits NK cell responses, they now hope that a drug can be developed that will improve the response of NK cells to this growth factor and help patients fight cancer with their own immune system. “This is about learning how to activate the NK cells of the individual patient and boost their immune system to tackle the disease,” Dr Huntington said. “We are hopeful our research will lead to new immunotherapies that supercharge the body’s Natural Killer cells and maintain it in a highly active state to more efficiently and specifically fight cancer.” The Australian Cancer Research Foundation has supported WEHI by providing three grants, totalling AUD 5.5million towards cutting edge cancer research equipment and technology. The original news post including the YouTube video was published on WEHI website.