TNFR2/14-3-3ε signaling complex instructs macrophage plasticity in inflammation and autoimmunity
Wenyu Fu, … , Png Loke, Chuan-ju Liu
Wenyu Fu, … , Png Loke, Chuan-ju Liu
Published June 29, 2021
Citation Information: J Clin Invest. 2021;131(16):e144016. https://doi.org/10.1172/JCI144016.
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Research Article Autoimmunity Inflammation

TNFR2/14-3-3ε signaling complex instructs macrophage plasticity in inflammation and autoimmunity

Abstract

TNFR1 and TNFR2 have received prominent attention because of their dominance in the pathogenesis of inflammation and autoimmunity. TNFR1 has been extensively studied and primarily mediates inflammation. TNFR2 remains far less studied, although emerging evidence demonstrates that TNFR2 plays an antiinflammatory and immunoregulatory role in various conditions and diseases. Herein, we report that TNFR2 regulates macrophage polarization, a highly dynamic process controlled by largely unidentified intracellular regulators. Using biochemical copurification and mass spectrometry approaches, we isolated the signaling molecule 14-3-3ε as a component of TNFR2 complexes in response to progranulin stimulation in macrophages. In addition, 14-3-3ε was essential for TNFR2 signaling–mediated regulation of macrophage polarization and switch. Both global and myeloid-specific deletion of 14-3-3ε resulted in exacerbated inflammatory arthritis and counteracted the protective effects of progranulin-mediated TNFR2 activation against inflammation and autoimmunity. TNFR2/14-3-3ε signaled through PI3K/Akt/mTOR to restrict NF-κB activation while simultaneously stimulating C/EBPβ activation, thereby instructing macrophage plasticity. Collectively, this study identifies 14-3-3ε as a previously unrecognized vital component of the TNFR2 receptor complex and provides new insights into the TNFR2 signaling, particularly its role in macrophage polarization with therapeutic implications for various inflammatory and autoimmune diseases with activation of the TNFR2/14-3-3ε antiinflammatory pathway.

Authors

Wenyu Fu, Wenhuo Hu, Young-Su Yi, Aubryanna Hettinghouse, Guodong Sun, Yufei Bi, Wenjun He, Lei Zhang, Guanmin Gao, Jody Liu, Kazuhito Toyo-oka, Guozhi Xiao, David B. Solit, Png Loke, Chuan-ju Liu

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Figure 1

TNFR2 signaling controls macrophage polarization.

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TNFR2 signaling controls macrophage polarization. (A) Schematic diagram ...
(A) Schematic diagram illustrating the in vitro experimental design. (B) Fold change of Il6 and Nos2 mRNA in WT and TNFR2–/– BMDMs polarized to M1 with LPS/IFN-γ in the presence or absence of 0.5 μg/mL PGRN or 2.5 μg/mL TY010 for 18 hours. (C) Fold change of Arg1 and Mgl1 mRNA in WT and TNFR2–/– BMDMs polarized to M2 with IL-4 in the presence or absence of 0.5 μg/mL PGRN or 2.5 μg/mL TY010 for 18 hours. (D and E) BMDMs from WT and TNFR2–/– were polarized to M2 (IL-4) or M1 (LPS/IFN-γ) for 18 hours. Media were removed and M2 macrophages were treated with M1 stimuli (LPS/IFN-γ) while M1 macrophages were treated with M2 stimuli (IL-4) with or without 0.5 μg/mL PGRN or 2.5 μg/mL TY010 for an additional 18 hours. Quantitative PCR (qPCR) was performed to measure the expression of Nos2 and Il6in M2 macrophages polarized to M1 (D), and the expression of Arg1 and Mgl1in M1 macrophages polarized to M2 (E). (F and G) Flow cytometry analysis of WT and TNFR2–/– BMDMs polarized to M1 (F) or M2 (G) in the absence and presence of PGRN. CD45+CD11b+ cells were gated, and iNOS+ cells or PD-L2 mean fluorescence intensity (MFI) were analyzed. Data are mean ± SD; n = 3 biological replicates; significant difference was analyzed by 1-way ANOVA with Bonferroni’s post hoc test; *P < 0.05 or **P < 0.01.