Natural born killers – watch the body’s immune cells in action


London: Scientists at London’s Imperial Colleage have captured the body’s immune cells at work.

The mechanism used by ‘Natural Killer’ immune cells in the human body to distinguish between diseased cells, which they are meant to destroy, and normal cells, which they are meant to leave alone, is revealed in new detail in research published in PLoS Biology.

Understanding how this aspect of the body’s natural defences works could help medical researchers develop new ways of boosting these defences to treat disease.

Natural Killer (NK) cells – a type of white blood cell – are a major component of the human body’s innate immune system. Over 1,000 NK cells are found in every drop of blood. They provide a fast frontline defence against tumours, viruses and bacterial infections, by latching onto and killing cells in the human body that are cancerous or are infected with a virus or a bacterial pathogen.

On their journey round the human body NK cells regularly latch onto normal non-diseased cells too, before moving off, leaving them unharmed. Previously, the process by which NK cells made the right decision to kill or not kill another cell was unclear.

Now, the team of researchers from Imperial College London have used high speed microscopy imaging techniques to observe the NK cell decision making process in action. This has revealed striking differences in the behaviour of NK cells when interacting with healthy or diseased cells.

The outcome of the decision making process is determined by how receptors on the surface of the NK cell interact with proteins on the surface of the captured cell. Every NK cell has two types of surface receptors – activators, which turn the killing mechanism ‘on’ and inhibitors which turn the killing mechanism ‘off’.

Professor Davis and his colleagues discovered that if a captured cell is diseased or cancerous, it interacts with a large number of the NK cell’s activating receptors, which makes the NK cell stop dead in its tracks and spread out over the captured cell. During this spreading process the NK cell continuously reads the ‘on’ and ‘off’ signals from its surface contact with the captured cell. If the ‘on’ signals dominate, the NK cell prolongs contact with the captured cell and eventually kills it.

Conversely if the captured cell is healthy, it interacts with more of the NK cell’s inhibiting receptors – and fewer of its activating receptors – meaning that the ‘off’ signals dominate and the ‘stopping and spreading’ process does not occur, allowing the NK cell to quickly move off in search of a new target.

Principal investigator of the new study, Professor Dan Davis from Imperial College London’s Department of Life Sciences, explains:

“Scientists have known for a long time that the proteins on the surface on Natural Killer cells are involved in answering the ‘to kill or not to kill?’ question, but we’ve not known exactly how these molecular cues are translated into the correct response. Our research has shown that information gleaned from its surface receptors tells the Natural Killer cell whether to stop patrolling and commence killing, or to move off quickly, and harmlessly, in search of another target.”

Dr Fiona Culley, lead author of the study from the National Heart and Lung Institute at Imperial, says that finding out how NK cells use this process to sift out diseased cells from normal ones paints a very clear picture of how these cells do their vital work:

“Considering that NK cells play such an important part in our immune response to cancer and disease, relatively little is known about their functionality – how exactly they work and how they interact with the cells they encounter inside us. This study adds significantly to our understanding of how Natural Killer cells distinguish between healthy and diseased cells.”

The research was funded primarily by the Lister Institute for Preventative Medicine and the Medical Research Council, with additional support from the Biotechnology and Biological Sciences Research Council, the Royal Society and the Wellcome Trust.

Another bad night’s sleep – free tips from the experts at TEMPUR


London: Getting a good night’s sleep helps keep the immune system operating at optimum, according to new research from Carnegie Mellon University.

The research discovered the risk of catching a cold was trebled amongst those who didn’t get enough sleep. Those who spent less than 92% of their time in bed asleep were five-and-a-half times more likely to become ill than those who were asleep for at least 98% of their time in bed. It is thought that lack of quality sleep impairs the immune system and the body’s ability to fight off the viruses that cause colds and flu.

More than a third of people in the UK regularly have trouble sleeping and millions wake up every morning feeling worse than when they went to bed.

UK bed manufacturer, TEMPUR, has come up with a helpful guide on how to get a good night night’s sleep.

Written in association with sleep expert, Dr Chris Idzikowski, ‘The Good Sleep Guide’ is an easy-to-follow educational consumer sleep guide with lots of practical tips and tricks to get the best night’s sleep possible, including the perfect bedtime routine and advice on choosing the right mattress.

According to TEMPUR, 80% of shoppers spend less than two minutes trying mattresses on which they are likely to sleep around 3,000 hours a year**, yet the right mattress can make a world of difference to our night’s rest. For example, TEMPUR pressure-relieving mattresses have been shown in clinical trials to improve quality of sleep by reducing tossing and turning by 83%.

The ‘Good Sleep Guide’ is available free to consumers by calling 08000 111081 or emailing: Further information is to follow, which I hope will be of interest for any relevant features you may be planning, however please do let me know if you need any additional information, images or copies of the guide.

he part of the brain which controls our emotions, moods, social interactions and decision making recovers from the strains of waking life during sleep. If allowed to, most young adults will sleep between seven and eight hours a night, but an unfortunate result of juggling work and family time, means that one in three of us get just five hours sleep a night.

Poor quality sleep is known to lead to problems with learning, memory, concentration and low mood. There are, however, a number of ways to help ensure you achieve the best night’s sleep possible. ‘The Good Sleep Guide’ is full of simple tips and tricks to help you get the perfect night’s rest, from ways to develop the right bedtime routine – including which foods will trigger sleep and which you should avoid – to creating the ideal sleeping environment.

Did you know that you will sleep better if the temperature of your bedroom is between 17 and 18 degrees and that you should avoid dim lighting in the bedroom as a quick transition between bright light and complete darkness triggers sleep? The guide also addresses common sleep problems and helps you get to grips with them by providing practical advice, including visualisation techniques which re-focus your mind away from day-to-day stresses and prepare your mind for sleep.

TEMPUR Information

TEMPUR Mattresses are made from unique TEMPUR Material, a proprietary, open celled, temperature sensitive material that conforms to and supports the individual user by evenly distributing body weight. The basis for the TEMPUR pressure relieving material was originally developed by NASA to protect astronauts against G Forces during lift off and re-entry to the earth’s atmosphere. Today TEMPUR is the only producer of mattresses and pillows worldwide to be endorsed by NASA and certified by the Space Foundation.

On conventional mattresses the body needs to adjust during the night. This is due to unrelieved pressure, which restricts blood flow and results in the build up of pressure, causing pain and forcing the body to reposition. TEMPUR Mattresses, on the other hand, mould to the exact shape and position of the body giving the neck, back, shoulders and feet the comfort and support they need. Pressure is evenly distributed thus reducing pressure points and practically eliminating the need for tossing and turning.

TEMPUR Products are recommended by over 30,000 medical professionals worldwide, and their beneficial properties are supported by clinical research. A trial at the Institution for Clinical & Physiological Research at the Lillhagen Hospital, Gothenburg, Sweden tested 23,000 patients over an eight year period of home and clinical use of the TEMPUR Mattress and Pillow. Patients suffered less pain, experienced enhanced deep sleep, and an 83% reduction in tossing and turning when using TEMPUR Products.

A whole host of celebrities are now claiming they have found the perfect sleeping partner – their TEMPUR Mattress including George Michael, Jane Seymour, Paris Hilton, The England Rugby Team, Paul McCartney, David Blaine, The Ozbournes, Kyran Bracken, Claire Sweeney, Charlie Dimmock Susan Hampshire and Noel Gallagher.

TEMPUR Mattress prices start from £675, and TEMPUR Pillows are priced from £69.95. For more information about TEMPUR Products, call 08000 111081 or visit