Intercellular telomere transfer extends T cell lifespan

The common view is that T-lymphocytes activate telomerase, a DNA polymerase that extends telomeres at chromosome ends, to delay senescence. We show that independently of telomerase, T cells elongate telomeres by acquiring telomere vesicles from antigen-presenting cells (APCs). Upon contact with T cells, APCs degraded shelterin to donate telomeres, which were cleaved by TZAP, and then transferred in extracellular vesicles (EVs) at the immunological synapse. Telomere vesicles retained the Rad51 recombination factor that enabled them to fuse with T cell chromosomal ends causing an average lengthening of ∼3000 base pairs. Thus, we identify a previously unknown telomere transfer program that supports T cell lifespan.

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Protein phosphatase 2A B55β limits CD8+ T cell lifespan following cytokine withdrawal

Journal of Clinical Investigation ◽

10.1172/jci129479 ◽

2020 ◽

Vol 130 (11) ◽

pp. 5989-6004

Author(s):

Noé Rodríguez-Rodríguez ◽

Iris K. Madera-Salcedo ◽

J. Alejandro Cisneros-Segura ◽

H. Benjamín García-González ◽

Sokratis A. Apostolidis ◽

...

Keyword(s):

T Cell ◽

Protein Phosphatase ◽

Protein Phosphatase 2A ◽

Cd8 T Cell ◽

Phosphatase 2A ◽

Cell Lifespan

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Bim Dictates Naive CD4 T Cell Lifespan and the Development of Age-Associated Functional Defects

The Journal of Immunology ◽

10.4049/jimmunol.1001668 ◽

2010 ◽

Vol 185 (8) ◽

pp. 4535-4544 ◽

Cited By ~ 33

Author(s):

Hirotake Tsukamoto ◽

Gail E. Huston ◽

John Dibble ◽

Debra K. Duso ◽

Susan L. Swain

Keyword(s):

T Cell ◽

Cd4 T Cell ◽

Cell Lifespan ◽

Functional Defects

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Electron microscope study of the secretory activity of epithelial cells in embryonic thymus

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010015945x ◽

1990 ◽

Vol 48 (3) ◽

pp. 382-383

Author(s):

H. Alasam

Keyword(s):

Cell Differentiation ◽

T Cell ◽

Epithelial Cells ◽

Electron Density ◽

Secretory Activity ◽

T Cell Differentiation ◽

High Electron ◽

Transmission Electron ◽

Medullary Epithelial Cells ◽

Thymic Factor

The possibility that intrathymic T-cell differentiation involves stem cell-lymphoid interactions in embryos led us to study the ultrastructure of epithelial cell in normal embryonic thymus. Studies in adult thymus showed that it produces several peptides that induce T-cell differentiation. Several of them have been chemically characterized, such as thymosin α 1, thymopoietin, thymic humoral factor or the serum thymic factor. It was suggested that most of these factors are secreted by populations of A and B-epithelial cells.Embryonic materials were obtained from inbred matings of Swiss Albino mice. Thymuses were disected from embryos 17 days old and prepared for transmission electron microscopy. Our studies showed that embryonic thymus at this stage contains undifferentiated and differentiated epithelial cells, large lymphoblasts, medium and few small lymphocytes (Fig. 5). No differences were found between cortical and medullary epithelial cells, in contrast to the findings of Van Vliet et al,. Epithelial cells were mostly of the A-type with low electron density in both cytoplasm and nucleus. However few B-type with high electron density were also found (Fig. 7).

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