Key gene 'controls disease fight'

Natural killer cells are key part of our immune system defence

A master gene that helps mobilise the immune system to fight disease has been discovered by UK scientists.

It causes stem cells in the blood to become disease-fighting "Natural Killer" (NK) immune cells.

It is hoped the discovery will lead to new ways to boost the body's production of these frontline cells - potentially creating a new way to kill cancer.

The Nature Immunology study may also help development of new treatments for type 1 diabetes and multiple sclerosis.

These conditions are caused by a malfunctioning immune system turning against the body's own tissues, and it is suspected that faulty NK cells play a key role in this process.

The researchers, from Imperial College London, University College London and the Medical Research Council's National Institute for Medical Research have created mice that lack the key gene - E4bp4.

If we understand how these cells function, we can hope to exploit this knowledge to improve treatments for cancer patients Ken Campbell Leukaemia Research

These animals are normal in every way except they have no NK cells at all.

In theory, they should provide scientists with a golden opportunity to pin down the role of NK cells in auto-immune diseases - and possibly in other conditions such as female infertility.

Properly functioning NK cells are a type of white blood cell central to the body's first line of defence, rapidly killing off tumour cells, viruses and bacterial infections.

The latest work shows that the E4bp4 gene controls production of the cells from blood stem cells in the bone marrow.

The aim now is to develop a drug treatment ramping up production of NK cells.

Currently, NK cells isolated from donated blood are sometimes used to treat cancer patients - but the effectiveness of donated cells is limited because NK cells can be slightly different from person to person.

'Donor incompatibility'

Lead researcher Dr Hugh Brady said: "If increased numbers of the patient's own blood stem cells could be coerced into differentiating into NK cells, via drug treatment, we would be able to bolster the body's cancer-fighting force, without having to deal with the problems of donor incompatibility."

The researchers were initially studying the effect of E4bp4 in a very rare but fatal form of childhood leukaemia when they discovered its importance for NK cells.

Ken Campbell, of the charity Leukaemia Research, said: "This study helps shed more light on the behaviour of NK cells, which is vital because if we understand how these cells function we can hope to exploit this knowledge to improve treatments for cancer patients."