Document Detail


Senescent phenotypes and telomere lengths of peripheral blood T-cells mobilized by acute exercise in humans.
MedLine Citation:
PMID:  20839490     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Acute bouts of aerobic exercise are known to mobilize antigen-experienced CD8+ T-cells expressing the cell surface marker of senescence, KLRG1, into the blood. It is not known; however if this is due to a selective mobilization of terminally differentiated T-cells (i.e., KLRG1 +/CD28-/CD57+) or a population of effector memory T-cells (i.e., KLRG1+/CD28+/CD57-) that have not reached terminal differentiation. The aim of this study was to further characterize KLRG1 + T-cells mobilized by acute exercise by assessing the co-expression of KLRG1 with CD28 or CD57 and to determine telomere lengths in the CD4+ and CD8+ T-cell subsets. Nine moderately trained male subjects completed an exhaustive treadmill running protocol at 80%. Blood lymphocytes isolated before, immediately after and 1h after exercise were labelled with antibodies against KLRG1, CD28 or CD57, CD4 or CD8 and CD3 for 4-color flow cytometry analysis. Telomere lengths in CD3+, CD4+ and CD8+ T-cells were determined using Q-PCR. The relative proportion of KLRG1 + cells among the CD8+ T-cells increased by 40% immediately after exercise, returning to baseline 1h later. This was due to a mobilization of KLRG1+/CD28- (61% increase), KLRG1+/CD57+ (56% increase) and to a lesser extent, KLRG1+/CD57- cells (24% increase). Telomeres in CD8+ T-cells displayed an increased relative length immediately after exercise, whereas no change occurred for CD4+ or the overall CD3+ T-cells. In conclusion, the increased frequency of KLRG1 +/CD8+ T-cells in blood after acute exercise is predominantly due to a selective mobilization of terminally differentiated T-cells. The increased relative telomere length in CD8+ T-cells after exercise might indicate that KLRG1+ cells mobilized by exercise are under stress or aberrant signaling-induced senescence (STASIS). We postulate that a frequent mobilization of these cells by acute exercise might eventually allow naïve T-cells to occupy the "vacant" immune space and increase the naïve T-cell repertoire.
Authors:
Richard J Simpson; Cormac Cosgrove; Meng M Chee; Brian K McFarlin; David B Bartlett; Guillaume Spielmann; Daniel P O'Connor; Hanspeter Pircher; Paul G Shiels
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Exercise immunology review     Volume:  16     ISSN:  1077-5552     ISO Abbreviation:  Exerc Immunol Rev     Publication Date:  2010  
Date Detail:
Created Date:  2010-09-15     Completed Date:  2010-10-18     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9505535     Medline TA:  Exerc Immunol Rev     Country:  Germany    
Other Details:
Languages:  eng     Pagination:  40-55     Citation Subset:  IM    
Affiliation:
Laboratory of Integrated Physiology, Department of Health and Human Performance, University of Houston, 3855 Holman Street, Houston, Texas 77204, USA. rjsimpson@uh.edu
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MeSH Terms
Descriptor/Qualifier:
Adult
Cell Aging / immunology*
Cell Differentiation / immunology
Cell Movement / immunology*
Cell Separation
Exercise*
Flow Cytometry
Humans
Lectins, C-Type / biosynthesis,  immunology
Male
Phenotype
Reverse Transcriptase Polymerase Chain Reaction
T-Lymphocyte Subsets / cytology*,  immunology,  metabolism
T-Lymphocytes / cytology*,  immunology,  metabolism
Telomere / immunology,  metabolism*
Trans-Activators / biosynthesis,  immunology
Chemical
Reg. No./Substance:
0/KLRG1 protein, human; 0/Lectins, C-Type; 0/Trans-Activators

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