Study conducted on mice by Stanford Medicine and the Rocky Mountain Laboratories of the US National Institutes of Health and published in the journal Nature, provides indications that it may one day be possible to rejuvenate the immune system of the elderly with a treatment that modulates the synthesis of a type of immune cell.

As our immune systems face more and more challenges from unknown bacteria and viruses, vaccination in the elderly is not as effective as in the younger, and new pathogens can take hold frighteningly quickly.

The cells the researchers targeted are a subset of so-called hematopoietic stem cells, or HSCs, which give rise to all other types of blood and immune system cells, including B and T lymphocytes. As we age, HSCs begin to favor increased production of other immune cells (myeloid cells) over lymphocytes, and this shift hinders our ability to fully respond to new viral or bacterial threats and makes our vaccination response much less robust than of younger people.

Treatment with an antibody given during the research, which targeted senescent cells for destruction, significantly improved the ability of the elderly animals’ immune systems to deal with a new virus, as well as respond to vaccination, allowing them to fight off a new threat months later. The treatment also reduced inflammation that occurs when an aging immune system fights a new pathogen.

“If we can revive the aging human immune system, as we did in mice, that could be a lifesaver when the next global pathogen emerges,” said Irving Weissman, professor of pathology and evolutionary biology at Stanford University and one of the lead authors of the study. research. Weissman was the first to isolate HSCs in mice and humans in the late 1980s.

Preclinical and clinical studies are needed to determine whether this approach may be feasible in humans. However, in an accompanying article published in Nature, Yasar Arfat Kasou and Robert Shiner of the University of California, San Diego, warn that increased lymphoid cell production in older adults could potentially increase the risk of developing tumors (such as leukemia). , which have been shown to be suppressed by reduced lymph production. “However, the burden of increased risk of lymphogenous leukemia could be offset by greater protection against infections and reduced risk of other cancers resulting from enhanced immune surveillance,” they add.

See here the link to the scientific publication.