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.
View: Text | PDF
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

×

Figure 5

Δ133p53 knockdown or p53β overexpression induces cellular senescence in CD8+CD28+ T lymphocytes.

Options: View larger image (or click on image) Download as PowerPoint
Δ133p53 knockdown or p53β overexpression induces cellular senescence in ...
(A) Δ133p53 siRNA– or control siRNA–nucleofected CD28+ cells were analyzed by immunoblot analysis of Δ133p53 and p53FL (donor 30, day 7). (B) Nucleofections were performed every 3–4 days, 5 consecutive times. Cumulative PDLs were plotted against days after the first nucleofection (donors 29–31). (C) Quantitative analysis of SA-β-gal activity (donors 29–31, day 18). (D) Representative dot plots for CD28 expression by flow cytometry (donor 30, day 18). (E) Quantitative analysis of CD28+ cells (donors 29–31, day 18). (F) Flag-tagged p53β- or control vector–transduced CD28+ cells were analyzed by immunoblot analysis of the indicated proteins after FACS sorting based on vector-derived GFP expression (donor 29, day 7). Overexpression of Flag-p53β was confirmed by TLQi9 and DO-1 antibodies. Δ133p53 was not substantially affected. (G) Cumulative PDLs of Flag-p53β–overexpressing CD28+ cells (donors 29 and 31). Cells with control vector are also shown. (H) Quantitative analysis of SA-β-gal activity (donor 29, day 19). (I) Quantitative RT-PCR analysis for IL6 and IL8 in p53β-reconstituted CD28+ cells (donors 29 and 31, day 19). B2M was used for normalization. (J and K) Frequency of PD-1+ (J) and LAG-3+ (K) cells (donors 32 and 33, day 19). Data are mean ± SD (B, C, E, H, and I), from triplicate assays (H). *P < 0.05; **P < 0.01.