London, Aug 25 (IANS): While attempting to find why immunity decreases with age leading to life-threatening diseases, researchers have cracked how to rejuvenate ageing immune cells.

As we age, our immune systems decline. Older people suffer from increased incidence and severity of both infections and cancer. Vaccination too becomes less efficient with age.

Now, a team of scientists from University College, London has demonstrated how an interplay between nutrition, metabolism and immunity is involved in the process of ageing.

Professor Arne Akbar's team showed that ageing in immune system cells known as 'T lymphocytes' was controlled by a molecule called 'p38 MAPK' that acts as a brake to prevent certain cellular functions.

They found that this braking action could be reversed by using a p38 MAPK inhibitor, suggesting the possibility of rejuvenating old T-cells using drug treatment.

In a new study published in the journal Nature Immunology, the group showed that p38 MAPK is activated by low nutrient levels, coupled with signals associated with age (senescence) within the cell.

"It has been suspected for a long time that nutrition, metabolism and immunity are linked and this paper provides a prototype mechanism of how nutrient and senescence signals converge to regulate the function of T-lymphocytes," Akbar explained.

In a second paper published in the Journal of Clinical Investigation, researchers showed that blocking p38 MAPK boosted the fitness of cells that had shown signs of ageing.

The two studies, supported by the Biotechnology and Biological Sciences Research Council (BBSRC), could help enhance immunity to disease through dietary instead of drug intervention and help make existing immune system therapies more effective, researchers noted.