New role for Natural Killers!
Posted on 27 August 2008
Natural Killer (or NK) cells are abundant white blood cells that were recognised over 30 years ago as being able to kill cancer cells in the test tube. Since that time, a role for NK cells in activating other white blood cells (including ‘T’ lymphocytes and phagocytes) and in directing how the immune system responds to a wide range of infections has also been established.
We need to consider more carefully exactly how we use therapies that affect NK cells, to maximize their beneficial role
Professor Paul Kaye
Because of these properties, NK have been widely regarded as being of benefit in the fight against cancer and infection, and methods to increase NK cell activity underpin a range of new experimental anti-cancer drugs and anti-infectives.
However, a research team in the University’s Centre for Immunology and Infection and led by Professor Paul Kaye, has now demonstrated that NK cells also make chemicals that inhibit immune responses.
The research, published in the latest issue of the journal Immunity, has shown that in an experimental model of the tropical disease visceral leishmaniasis, too many NK cells can actually make the disease worse. They have identified that NK cells produce a chemical called interleukin-10 that can counteract many of the otherwise beneficial effects of these cells.
Professor Kaye said: "Other researchers have suggested in the past that NK cells might not always be good for you, but we now have the first direct evidence that this can actually be the case. Although we have worked on an infectious disease, the same is likely to be true for NK cells in cancer. So, in practical terms, it means that we need to consider more carefully exactly how we use therapies that affect NK cells, to maximize their beneficial role."
The new findings also open up the potential of developing new drugs that specifically target the beneficial properties of NK cells, and which leave their inhibitory properties switched off. Conversely, in autoimmune diseases, where the immune system is too active, it may be possible to stimulate NK cells to turn it off.
ENDS
Notes to editors:
- ‘Post-transcriptional regulation of Il10 gene expression allows NK cells to express immunoregulatory function.’ Maroof et. al. is available at: http://www.immunity.com/content/article/fulltext?uid=PIIS1074761308003324
- The Centre for Immunology and Infection is a research centre of the University of York’s Department of Biology and the Hull York Medical School, based on the Heslington campus. The Centre houses approximately 50 research staff and students, working on a range of infectious and non-infectious diseases.
- A new £4.5M research building, to expand the work of the Centre and provide facilities for volunteer studies and clinical trials, has been funded by the University of York, the Hull York Medical School and the Wolfson Foundation, and is in the final stages of planning. The new building is due to open in mid-2010.
- The Hull York Medical School (HYMS) is a joint venture between the Universities of Hull and York and the NHS. It admitted its first medical students in 2003 and is consolidating its research base with strong collaborative links in and between the two universities and clinicians in the region. Students at HYMS are based at one of the two universities for their first two years, and have clinical placements in primary care and hospitals in North Yorkshire, East Yorkshire and Northern Lincolnshire. The first cohort of medical students graduated in 2008.
- The University of York’s Department of Biology is one of the leading centres for biological teaching and research in the UK. The Department both teaches degree courses and undertakes research across the whole spectrum of modern Biology, from molecular genetics and biochemistry to ecology.