Some human blood stem cells remember inflammation in mice
Experiments with human cord blood cells from 62 donors identified a less active stem-cell subset that retained molecular changes after inflammation in mice.
Stake: An author holds patents with Trillium Therapeutics Inc/Pfizer.
Edited by Boris Djordjevic · AgingResearch.News
Human cord blood stem cells, which produce blood cells, were transplanted into mice in experiments testing responses to inflammation and recovery. Researchers randomly assigned mice to inflammation-triggering injections or a control solution and analyzed individual human cells. They identified two stem-cell subsets. One retained a distinct pattern of gene activity after recovery from inflammation. This inflammatory-memory subset was less active and produced fewer blood cells.
In separate observational analyses of human samples, the subset’s gene-activity pattern was enriched in stem cells across conditions including COVID-19 recovery, sickle cell disease and aging. Descendant immune cells carried the inflammatory pattern both in the mouse experiments and in human samples. In population cohorts, enrichment of the pattern in circulating blood cells was associated with a higher score estimating risk of death from any cause.
Why it matters
Blood stem cells must sustain blood production throughout life. The work addresses how a history of inflammatory stress may relate to age-related changes in this system.
Caveats
The experimental findings came from human cells transplanted into mice, not experiments in people. The population result concerned a mortality risk score and did not establish that inflammatory memory causes earlier death.
