p53 isoforms regulate aging- and tumor-associated replicative senescence in T lymphocytes
Abdul M. Mondal, … , David P. Lane, Curtis C. Harris
Abdul M. Mondal, … , David P. Lane, Curtis C. Harris
Published November 15, 2013
Citation Information: J Clin Invest. 2013;123(12):5247-5257. https://doi.org/10.1172/JCI70355.
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Research Article Aging

p53 isoforms regulate aging- and tumor-associated replicative senescence in T lymphocytes

Abstract

Cellular senescence contributes to aging and decline in tissue function. p53 isoform switching regulates replicative senescence in cultured fibroblasts and is associated with tumor progression. Here, we found that the endogenous p53 isoforms Δ133p53 and p53β are physiological regulators of proliferation and senescence in human T lymphocytes in vivo. Peripheral blood CD8+ T lymphocytes collected from healthy donors displayed an age-dependent accumulation of senescent cells (CD28–CD57+) with decreased Δ133p53 and increased p53β expression. Human lung tumor-associated CD8+ T lymphocytes also harbored senescent cells. Cultured CD8+ blood T lymphocytes underwent replicative senescence that was associated with loss of CD28 and Δ133p53 protein. In poorly proliferative, Δ133p53-low CD8+CD28– cells, reconstituted expression of either Δ133p53 or CD28 upregulated endogenous expression of each other, which restored cell proliferation, extended replicative lifespan and rescued senescence phenotypes. Conversely, Δ133p53 knockdown or p53β overexpression in CD8+CD28+ cells inhibited cell proliferation and induced senescence. This study establishes a role for Δ133p53 and p53β in regulation of cellular proliferation and senescence in vivo. Furthermore, Δ133p53-induced restoration of cellular replicative potential may lead to a new therapeutic paradigm for treating immunosenescence disorders, including those associated with aging, cancer, autoimmune diseases, and HIV infection.

Authors

Abdul M. Mondal, Izumi Horikawa, Sharon R. Pine, Kaori Fujita, Katherine M. Morgan, Elsa Vera, Sharlyn J. Mazur, Ettore Appella, Borivoj Vojtesek, Maria A. Blasco, David P. Lane, Curtis C. Harris

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Figure 4

Reconstitution of CD28 or Δ133p53 expression extends replicative lifespan in CD8+CD28– T lymphocytes.

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Reconstitution of CD28 or Δ133p53 expression extends replicative lifespa...
(A) Cumulative PDLs of CD28-reconstituted CD28– cells (donors 29 and 30) after puromycin selection. Empty vector was used as control. (B) Immunoblot analysis of Δ133p53 and p53FL (donor 29, days 27 and 55). β-actin was the loading control for normalization. Expression level relative to control is shown below. (C) Quantitative RT-PCR analysis for IL6 and IL8 in CD28-reconstituted CD28– cells (donors 29 and 30, day 20). B2M was used for normalization. (D) Reconstitution of Δ133p53 expression in CD28– cells (donor 29). Immunoblot analysis was performed 12 days after blasticidin selection. p53β and p53FL levels were not affected. p53β bands are denoted by arrowheads. (E) Cumulative PDLs of Δ133p53-reconstituted CD28– cells after blasticidin selection (donors 29 and 30). Cells with control vector are also shown. (F) Quantitative RT-PCR of CD28 mRNA (donor 29, day 19). B2M was used for normalization. (G) Representative dot plots for CD28 expression by flow cytometry (donor 29, day 19). (H) Frequency of CD28+ cells at days 3, 12, 19 (as in G), and 27 (donor 29). (I) Quantitative RT-PCR analysis for IL6 and IL8 in Δ133p53-reconstituted CD28– cells (donors 29 and 30, day 19). B2M was used for normalization. Data are mean ± SD (C, F, and I), from triplicate assays (F). *P < 0.05; **P < 0.01; ***P < 0.001.