Researchers led by scientists at the University College London have discovered a new mechanism that controls aging in white blood cells, offering the possibility of temporarily reversing the effects of aging on immunity and possibly boosting the immune systems of older people short-term.

The research team took some human blood samples and looked closely at the white blood cells. They saw that some were inactive and yet had long telomeres (special caps on the ends of our DNA that have a built-in lifespan of effectiveness). This suggested to the researchers that there must be another mechanism in the immune system causing cells to become deactivated that was independent of telomere length.

When the researchers blocked this newly identified pathway in the lab, they found that the white blood cells appeared to be reactivated.

This research opens up the possibility of giving older people’s immune systems a temporary boost to help them fight off infections — but it is not a fountain of eternal youth, the researchers said.

Ref.: D. Di Mitri, et al., Reversible Senescence in Human CD4 CD45RA CD27 — Memory T Cells, The Journal of Immunology, 2011; [DOI: 10.4049/jimmunol.1100978]