Longevity & AgingHuman Stem Cells Retain Inflammatory Memory That Shapes Lifelong Blood Health
Scientists have identified a unique subset of human haematopoietic stem cells (HSCs) called HSC-iM (inflammatory memory) that retains molecular traces of previous inflammatory stress. Using xenograft models and single-cell multiomics, the team showed these cells become more quiescent and restrain blood cell production after inflammation. The HSC-iM signature appeared across COVID-19 recovery, sickle cell disease, aging, and clonal haematopoiesis, confirming its physiological relevance. Clonal haematopoiesis mutations partially counteracted these effects by promoting HSC activation. Strikingly, the HSC-iM program was transmitted to immune progeny and, when detected in circulating blood, was associated with significantly elevated all-cause mortality risk in population cohorts.
