In this episode, we welcome Dr. Lanna, who sheds light on a novel mechanism of T-cell rejuvenation that could significantly impact our understanding of immune protection. Traditionally, it's thought that T lymphocytes activate telomerase to avoid senescence. However, Dr. Lanna introduces us to a distinct process independent of telomerase action, where certain T cells, primarily naive and central memory cells, elongate their telomeres by receiving telomere vesicles from antigen-presenting cells (APCs). She explains the fascinating process of how APCs degrade shelterin to donate telomeres, which are then cleaved by the telomere trimming factor TZAP and transferred to T cells via extracellular vesicles. We delve into how these telomere vesicles, retaining the Rad51 recombination factor, enable telomere fusion, effectively lengthening T-cell chromosome ends. Dr. Lanna discusses the implications of these antigen-specific T cell populations, whose aging decisions are based on telomere vesicle transfer, hinting at a potential mechanism for long-lasting immune protection.

Keywords: T Lymphocytes, Telomerase, Senescence, Antigen-Presenting Cells, Telomere Vesicles, TZAP, Rad51 Recombination Factor, Immune Protection, Telomere Elongation.

Lanna, A., et al. An intercellular transfer of telomeres rescues T cells from senescence and promotes long-term immunological memory. Nat Cell Biol (2022). https://doi.org/10.1038/s41556-022-00991-z