Cholesterol suppresses human iTreg differentiation and nTreg function through mitochondria-related mechanisms

Huanzhi Zhang; Ni Xia; Tingting Tang; Shaofang Nie; Lingfeng Zha; Min Zhang; Bingjie Lv; Yuzhi Lu; Jiao Jiao; Jingyong Li; Xiang Cheng

doi:10.1186/s12967-023-03896-z

Cholesterol suppresses human iTreg differentiation and nTreg function through mitochondria-related mechanisms

J Transl Med. 2023 Mar 27;21(1):224. doi: 10.1186/s12967-023-03896-z.

Authors

Huanzhi Zhang^#^{1

2

3}, Ni Xia^#^{1

2

3}, Tingting Tang^{1

2

3}, Shaofang Nie^{1

2

3}, Lingfeng Zha^{1

2

3}, Min Zhang^{1

2

3}, Bingjie Lv^{1

2

3}, Yuzhi Lu^{1

2

3}, Jiao Jiao^{1

2

3}, Jingyong Li^{1

2

3}, Xiang Cheng^{4

5

6}

Affiliations

¹ Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
² Hubei Key Laboratory of Biological Targeted Therapy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
³ Hubei Provincial Engineering Research Center of Immunological Diagnosis and Therapy for Cardiovascular Diseases, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan, 430022, China.
⁴ Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China. nathancx@hust.edu.cn.
⁵ Hubei Key Laboratory of Biological Targeted Therapy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China. nathancx@hust.edu.cn.
⁶ Hubei Provincial Engineering Research Center of Immunological Diagnosis and Therapy for Cardiovascular Diseases, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan, 430022, China. nathancx@hust.edu.cn.

^# Contributed equally.

Abstract

Background: Both the crystalline and soluble forms of cholesterol increase macrophage secretion of interleukin 1β (IL-1β), aggravating the inflammatory response in atherosclerosis (AS). However, the link between cholesterol and regulatory T cells (Tregs) remains unclear. This study aimed to investigate the effect of cholesterol treatment on Tregs.

Methods: Differentiation of induced Tregs (iTregs) was analyzed using flow cytometry. The expression of hypoxia-inducible factor-1a (HIF-1a) and its target genes was measured by western blotting and/or RT-qPCR. Two reporter jurkat cell lines were constructed by lentiviral transfection. Mitochondrial function and the structure of natural Tregs (nTregs) were determined by tetramethylrhodamine (TMRM) and mitoSOX staining, Seahorse assay, and electron microscopy. The immunoregulatory function of nTregs was determined by nTreg-macrophage co-culture assay and ELISA.

Results: Cholesterol treatment suppressed iTreg differentiation and impaired nTreg function. Mechanistically, cholesterol induced the production of mitochondrial reactive oxygen species (mtROS) in naïve T cells, inhibiting the degradation of HIF-1α and unleashing its inhibitory effects on iTreg differentiation. Furthermore, cholesterol-induced mitochondrial oxidative damage impaired the immunosuppressive function of nTregs. Mixed lymphocyte reaction and nTreg-macrophage co-culture assays revealed that cholesterol treatment compromised the ability of nTregs to inhibit pro-inflammatory conventional T cell proliferation and promote the anti-inflammatory functions of macrophages. Finally, mitoTEMPO (MT), a specific mtROS scavenger, restored iTreg differentiation and protected nTreg from further deterioration.

Conclusion: Our findings suggest that cholesterol may aggravate inflammation within AS plaques by acting on both iTregs and nTregs, and that MT may be a promising anti-atherogenic drug.

Keywords: Atherosclerosis; Cholesterol; Mitochondrial reactive oxygen species; Regulatory T cells; mitoTEMPO.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Cell Differentiation
Coculture Techniques
Forkhead Transcription Factors / metabolism
Humans
Inflammation* / metabolism
Mitochondria / metabolism
T-Lymphocytes, Regulatory*

Substances

Forkhead Transcription Factors