Myeloperoxidase-anchored ENO1 mediates neutrophil extracellular trap DNA to enhance Treg differentiation via IFITM2 during sepsis
Yi Jiang, Shenjia Gao, Xiya Li, Hao Sun, Xinyi Wu, Jiahui Gu, Zhaoyuan Chen, Han Wu, Xiaoqiang Zhao, Tongtong Zhang, Ronen Ben-Ami, Yuan Le, Timothy R. Billiar, Changhong Miao, Jie Zhang, Jun Wang, Wankun Chen
Yi Jiang, Shenjia Gao, Xiya Li, Hao Sun, Xinyi Wu, Jiahui Gu, Zhaoyuan Chen, Han Wu, Xiaoqiang Zhao, Tongtong Zhang, Ronen Ben-Ami, Yuan Le, Timothy R. Billiar, Changhong Miao, Jie Zhang, Jun Wang, Wankun Chen
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Research Article Immunology Infectious disease

Myeloperoxidase-anchored ENO1 mediates neutrophil extracellular trap DNA to enhance Treg differentiation via IFITM2 during sepsis

Abstract

Sepsis is a life-threatening disease caused by a dysfunctional host response to infection. During sepsis, inflammation-related immunosuppression is the critical factor causing secondary infection and multiple organ dysfunction syndrome. The regulatory mechanisms underlying Treg differentiation and function, which significantly contribute to septic immunosuppression, require further clarification. In this study, we found that neutrophil extracellular traps (NETs) participated in the development of sepsis-induced immunosuppression by enhancing Treg differentiation and function via direct interaction with CD4+ T cells. Briefly, NETs anchored enolase 1 (ENO1) on the membrane of CD4+ T cells through its key protein myeloperoxidase (MPO) and subsequently recruited interferon-induced transmembrane protein 2 (IFITM2). IFITM2 acted as a DNA receptor that sensed NET-DNA and activated intracellular RAS-associated protein 1B (RAP1B) and its downstream ERK signaling pathway to promote Treg differentiation and function. ENO1 inhibition significantly attenuated NET-induced Treg differentiation and alleviated sepsis in mice. Overall, we demonstrated the role of NETs in sepsis-induced immunosuppression by enhancing Treg differentiation, identified ENO1 as an anchor of NET-MPO, and elucidated the downstream molecular mechanism by which IFITM2-RAP1B-ERK regulates Treg differentiation. These findings improve our understanding of the immunopathogenesis of sepsis and provide potential therapeutic targets for sepsis-induced immunosuppression.

Authors

Yi Jiang, Shenjia Gao, Xiya Li, Hao Sun, Xinyi Wu, Jiahui Gu, Zhaoyuan Chen, Han Wu, Xiaoqiang Zhao, Tongtong Zhang, Ronen Ben-Ami, Yuan Le, Timothy R. Billiar, Changhong Miao, Jie Zhang, Jun Wang, Wankun Chen

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Figure 6

NDMC activated the ERK pathway via RAP1B to promote Treg differentiation and function.

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NDMC activated the ERK pathway via RAP1B to promote Treg differentiation...
(A) Naive CD4+ T cells were treated with NDMC (100 ng/mL) or vehicle under Treg differentiation conditions. The protein expression levels of RAP1B, ERK1/2, and p-ERK1/2 were then determined by Western blotting. (B) RAP1B, ERK1/2, and p-ERK1/2 protein expression in naive CD4+ T cells under Treg differentiation conditions with or without NDMC (100 ng/mL) or DNase I (2 μg/mL) treatment was evaluated by Western blotting. (C) ERK1/2 and p-ERK1/2 expression in Tregs from the spleens of WT mice or Eno1fl/fl Cd4Cre mice 7 days after the CLP or sham procedure was determined by Western blotting. (D) Naive CD4+ T cells were transfected with Rap1b siRNA or control siRNA and then induced to differentiate into Tregs in the presence or absence of NDMC (100 ng/mL). The protein expression levels of RAP1B, ERK1/2, and p-ERK1/2 were then determined by Western blotting. (E–G) The ERK inhibitor SCH772984 (300nM) was added to the in vitro Treg differentiation cultures with or without NDMC (100 ng/mL). (E) The proportion of induced Tregs was assessed by flow cytometry (n = 3). (F) The expression of CD152 in Tregs was determined by flow cytometry (n = 3). (G) The expression of ENO1 on Tregs was determined by flow cytometry (n = 3). Data shown are representative of 3 independent experiments (A–G) and are presented as mean ± SD. *P < 0.05, **P < 0.01, ***P < 0.001. Two-way ANOVA was used for E–G.