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
View: Text | PDF
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

×

Figure 2

The NDMC was sufficient for regulating Tregs.

Options: View larger image (or click on image) Download as PowerPoint
The NDMC was sufficient for regulating Tregs. (A and B) Mice in the inte...
(A and B) Mice in the intervention group received i.p. injections of NET-degrading DNase I (5 mg/kg), while vehicle-treated mice received PBS daily from the day before CLP or sham operation until the end of the experiment, 7 days after operation. (A) The proportion of Tregs in the spleen was measured by flow cytometry (n = 6). (B) The expression of CD152 in Tregs from the spleens of CLP or sham mice with or without DNase I (5 mg/kg) was detected by flow cytometry (n = 6). (C) NET (100 ng/mL), DNase I (2 μg/mL), or vehicle (PBS) was administered to the Treg differentiation system in vitro, and the proportion of induced Tregs was determined by flow cytometry (n = 3). (D) Suppressive function of Tregs pretreated with NETs (100 ng/mL) and DNase I (2 μg/mL) or vehicle on the proliferation of Teffs was determined (n = 3). (E) NETs (100 ng/mL) or purified NET-DNA (100 ng/mL) were added during in vitro Treg differentiation, and the proportion of Tregs was measured by flow cytometry (n = 3). (F) Mice in the intervention group were given an i.p. injection of the selective MPO inhibitor AZD5904 (10 mg/kg) daily from the day before CLP or sham operation, while vehicle-treated mice were given PBS until the end of the experiment on day 7 after surgery. The proportion of Tregs in the spleen was detected by flow cytometry (n = 6). (G) Treg differentiation in the NET-treated (100 ng/mL) or control group was stimulated with AZD5904 (10 μM) or vehicle. The proportion of Tregs obtained was measured by flow cytometry (n = 3). (H) Different concentrations of purified MPO (1, 10, and 100 ng/mL) or NETs (100 ng/mL) were added to the in vitro Treg differentiation system. Flow cytometry was used to assess the proportion of Tregs obtained (n = 3). (I) NETs (100 ng/mL) or NDMC (100 ng/mL) were administered during in vitro Treg differentiation for 48 hours, and the proportion of induced Tregs was determined by flow cytometry (n = 3). (J) The in vitro suppressive function of Tregs on the proliferation of Teffs was assessed, with or without the pretreatment of NDMC (100 ng/mL) for 48 hours (n = 3). Data are representative of 3 independent experiments (A–J). Data are presented as mean ± SD. *P < 0.05, **P < 0.01, ***P < 0.001. Two-way ANOVA was used for A–H and J, and 1-way ANOVA was used for I.