USP16-mediated deubiquitination of calcineurin A controls peripheral T cell maintenance
Yu Zhang, … , Yi-yuan Li, Jin Jin
Yu Zhang, … , Yi-yuan Li, Jin Jin
Published May 28, 2019
Citation Information: J Clin Invest. 2019;129(7):2856-2871. https://doi.org/10.1172/JCI123801.
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Research Article Cell biology Immunology

USP16-mediated deubiquitination of calcineurin A controls peripheral T cell maintenance

Abstract

Calcineurin acts as a calcium-activated phosphatase that dephosphorylates various substrates, including members of the nuclear factor of activated T cells (NFAT) family, to trigger their nuclear translocation and transcriptional activity. However, the detailed mechanism regulating the recruitment of NFATs to calcineurin remains poorly understood. Here, we report that calcineurin A (CNA), encoded by PPP3CB or PPP3CC, is constitutively ubiquitinated on lysine 327, and this polyubiquitin chain is rapidly removed by ubiquitin carboxyl-terminal hydrolase 16 (USP16) in response to intracellular calcium stimulation. The K29-linked ubiquitination of CNA impairs NFAT recruitment and transcription of NFAT-targeted genes. USP16 deficiency prevents calcium-triggered deubiquitination of CNA in a manner consistent with defective maintenance and proliferation of peripheral T cells. T cell–specific USP16 knockout mice exhibit reduced severity of experimental autoimmune encephalitis and inflammatory bowel disease. Our data reveal the physiological function of CNA ubiquitination and its deubiquitinase USP16 in peripheral T cells. Notably, our results highlight a critical mechanism for the regulation of calcineurin activity and a novel immunosuppressive drug target for the treatment of autoimmune diseases.

Authors

Yu Zhang, Rong-bei Liu, Qian Cao, Ke-qi Fan, Ling-jie Huang, Jian-shuai Yu, Zheng-jun Gao, Tao Huang, Jiang-yan Zhong, Xin-tao Mao, Fei Wang, Peng Xiao, Yuan Zhao, Xin-hua Feng, Yi-yuan Li, Jin Jin

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Figure 7

USP16 deficiency alleviates T cell–mediated colitis.

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USP16 deficiency alleviates T cell–mediated colitis. (A) Immunofluoresce...
(A) Immunofluorescence images of USP16 and CD4 staining in human colon tissue sections from healthy donors or from patients with ulcerative colitis (UC) or Crohn’s disease (CD) (n = 5). Scale bar: 50 μm. (B) PBMCs or CD4+ T cells in peripheral blood from patients with UC or CD, or healthy donors were collected. qRT-PCR analysis of USP16 mRNA levels in these cells. (C) Spearman correlation analysis of USP16 mRNA levels and CD activity index (CDAI) scores. (D–E) Rag1–/– mice (6 to 8 weeks old) were intraperitoneally injected with CD4+CD25–CD45RBhi T cells (5 × 105) isolated from 6- to 8-week-old WT or USP16-KO donor mice (female, n = 5/group). Body weight (D) and survival curve (E) were monitored weekly. (F) Four weeks after the injection, the colon length was measured and presented as a summary graph. (G) Representative H&E slides of proximal colon sections. Scale bar: 200 μm. (H) FACS analysis of CD4+ T cells in spleen and mesenteric lymph nodes (mLNs) of the recipient mice. Data are representative of 3 independent experiments with 3 different patients (A), 1 experiment with 5 mice each group (D and E), and 3 independent experiments with 3 mice each group (F and H). The error bars show the mean ± SEM. The significance of difference in B was determined by Dunnett’s multiple comparisons test. Gehan-Breslow-Wilcoxon test was used for E. The significances of differences in all other 2-group comparisons were determined by 2-tailed Student’s t test. *P < 0.05; **P < 0.01; ***P < 0.001.