Proteasome activity regulates CD8+ T lymphocyte metabolism and fate specification
Christella E. Widjaja, … , Huib Ovaa, John T. Chang
Christella E. Widjaja, … , Huib Ovaa, John T. Chang
Published August 28, 2017
Citation Information: J Clin Invest. 2017;127(10):3609-3623. https://doi.org/10.1172/JCI90895.
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Research Article Immunology

Proteasome activity regulates CD8+ T lymphocyte metabolism and fate specification

Abstract

During an immune response, CD8+ T lymphocytes can undergo asymmetric division, giving rise to daughter cells that exhibit distinct tendencies to adopt terminal effector and memory cell fates. Here we show that “pre-effector” and “pre-memory” cells resulting from the first CD8+ T cell division in vivo exhibited low and high rates of endogenous proteasome activity, respectively. Pharmacologic reduction of proteasome activity in CD8+ T cells early during differentiation resulted in acquisition of terminal effector cell characteristics, whereas enhancement of proteasome activity conferred attributes of memory lymphocytes. Transcriptomic and proteomic analyses revealed that modulating proteasome activity in CD8+ T cells affected cellular metabolism. These metabolic changes were mediated, in part, through differential expression of Myc, a transcription factor that controls glycolysis and metabolic reprogramming. Taken together, these results demonstrate that proteasome activity is an important regulator of CD8+ T cell fate and raise the possibility that increasing proteasome activity may be a useful therapeutic strategy to enhance the generation of memory lymphocytes.

Authors

Christella E. Widjaja, Jocelyn G. Olvera, Patrick J. Metz, Anthony T. Phan, Jeffrey N. Savas, Gerjan de Bruin, Yves Leestemaker, Celia R. Berkers, Annemieke de Jong, Bogdan I. Florea, Kathleen Fisch, Justine Lopez, Stephanie H. Kim, Daniel A. Garcia, Stephen Searles, Jack D. Bui, Aaron N. Chang, John R. Yates III, Ananda W. Goldrath, Hermen S. Overkleeft, Huib Ovaa, John T. Chang

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Figure 1

Differentially fated CD8+ T cells exhibit distinct rates of endogenous proteasome activity.

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Differentially fated CD8+ T cells exhibit distinct rates of endogenous p...
(A) Proteasome activity, assessed by flow cytometry, of gated first division (second CFSE peak) of putative pre-effector IL-2RαhiCD62Llo and pre-memory IL-2RαloCD62Lhi OT-I CFSE-labeled CD8+ T cells adoptively transferred into recipient mice subsequently infected with Lm-OVA and analyzed 45 hours after infection. (B) Expression of Tbx21, Gzmb, Il7r, and Tcf1 mRNA in FACS-sorted first-division proteasome activityloIL-2RαhiCD62Llo (red bars) and proteasome activityhiIL-2RαloCD62Lhi (blue bars) cells. Expression is normalized to the average of Rpl13 and Rn18s mRNA. (C) Flow cytometry analysis (left) and mean fluorescence intensity (MFI) of T-bet, granzyme B, and Bcl-2 in first-division proteasome activityloIL-2RαhiCD62Llo (red) and proteasome activityhiIL-2RαloCD62Lhi (blue) cells. Gray histograms represent isotype control–stained first-division cells. (D) Proteasome activity, assessed by flow cytometry, of gated naive (CD8+CD45.1+CD62LhiCD44lo cells; uninfected mice), terminal effector (CD8+CD45.1+CD44hiKLRG1hiIL-7Rlo cells; 7 days after infection), effector memory (CD8+CD45.1+CD44hiCD62Llo; 60 days after infection), and central memory (CD8+CD45.1+CD44hiCD62Lhi; 60 days after infection) adoptively transferred into CD45.2 recipient mice followed by Lm-OVA infection and analyzed 7 or 60 days after infection. Data are representative of at least 3 independent experiments (A, C, and D) or 3 biological replicates from 3 independent experiments (B) with n ≥ 4 mice per group. Error bars represent SEM of 3 replicates. N.S., not significant (P > 0.05), **P < 0.01, ***P < 0.001 (A–C, Student’s 2-tailed t test; D, 1-way ANOVA with Dunnett’s post-test).