Lymphocyte maintenance during healthy aging requires no substantial alterations in cellular turnover |
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| Authors: | Liset Westera Vera van Hoeven Julia Drylewicz Gerrit Spierenburg Jeroen F van Velzen Rob J de Boer Kiki Tesselaar José A M Borghans |
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| Institution: | 1. Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, Utrecht, The Netherlands;2. Theoretical Biology and Bioinformatics, Department of Biology, Utrecht University, Utrecht, The Netherlands |
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| Abstract: | In healthy humans, lymphocyte populations are maintained at a relatively constant size throughout life, reflecting a balance between lymphocyte production and loss. Given the profound immunological changes that occur during healthy aging, including a significant decline in T‐cell production by the thymus, lymphocyte maintenance in the elderly is generally thought to require homeostatic alterations in lymphocyte dynamics. Surprisingly, using in vivo 2H2O labeling, we find similar dynamics of most lymphocyte subsets between young adult and elderly healthy individuals. As the contribution of thymic output to T‐cell production is only minor from young adulthood onward, compensatory increases in peripheral T‐cell division rates are not required to maintain the T‐cell pool, despite a tenfold decline in thymic output. These fundamental insights will aid the interpretation of further research into aging and clinical conditions related to disturbed lymphocyte dynamics. |
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| Keywords: | healthy aging homeostasis lymphocyte turnover mathematical modeling stable isotope labeling thymus involution |
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