Single-cell analyses of global cohorts outline determinants of immune aging and link the ratio of GZMK(+) to GZMB(+) Tem cells to health trajectories.

The GZMK(+)/GZMB(+) Tem cell ratio predicts health trajectories and distinguishes healthy from pathology-associated immune aging in 2,609 individuals.

• Why it matters: Understanding immune aging variability is crucial for developing interventions to promote healthy aging and prevent age-related diseases.
• What they did: Researchers integrated seven large-scale single-cell PBMC datasets and a new cohort, analyzing 2,609 healthy individuals across diverse ages, sexes, and ancestries, to identify immune remodeling patterns.
• The result: A higher Tem GZMB(+) plasma signature correlates with inflammaging, poor health, and increased risks of mortality and immune-related diseases, providing a potential biomarker for monitoring immune aging.