Human Stem Cell-like Memory T Cells Are Maintained in a State of Dynamic Flux.
Level 3 - non-randomized controlled study
Prospective observational isotope labeling study comparing young and elderly human cohorts
PubMed 27974195 · doi:10.1016/j.celrep.2016.11.037
What was done
The authors investigated how human stem cell-like memory T (TSCM) cells are maintained across the human lifespan. In vivo turnover of TSCM cells was measured in young and elderly human subjects using stable isotope labeling with heavy water. Cellular proliferation markers (Ki67 expression), telomerase activity, and telomere length dynamics were also assessed.
What was found
The abstract reports no numerical values, kinetic parameters, or statistical measures. Qualitatively, it reports that TSCM cells in both young and elderly subjects undergo continuous proliferation rather than dormancy, displaying high levels of active telomerase and Ki67 alongside limited telomere length erosion.
Why it matters
This study indicates that immunological memory mediated by human TSCM cells is maintained dynamically via ongoing self-renewal rather than by a static, dormant pool across the lifespan.
Limits
The abstract omits sample size, participant demographics, quantitative labeling rates, and variance metrics. Functional memory recall against specific antigens was not reported in the abstract.
Cited by
- contradicts The cells that make up the human immune system turn over and are replaced with new cells every 90 to 120 days.