Mettl14 sustains FOXP3 expression to promote the differentiation and functions of induced-regulatory T cells via the mTOR signaling pathway

Yanzhuo Liu; Yinglin Yuan; Zili Zhou; Xiaomei Jiang; Shu He; Fan Wei; Yuanyuan Cui; Lu Yang; Gaoping Zhao

doi:10.1016/j.imlet.2023.04.008

Mettl14 sustains FOXP3 expression to promote the differentiation and functions of induced-regulatory T cells via the mTOR signaling pathway

Immunol Lett. 2023 Jun:258:35-44. doi: 10.1016/j.imlet.2023.04.008. Epub 2023 Apr 29.

Authors

Yanzhuo Liu¹, Yinglin Yuan¹, Zili Zhou², Xiaomei Jiang¹, Shu He³, Fan Wei⁴, Yuanyuan Cui¹, Lu Yang⁵, Gaoping Zhao⁶

Affiliations

¹ Department of Gastrointestinal Surgery, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan Province, 610072, China; Clinical Immunology Translational Medicine Key Laboratory of Sichuan Province, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan Province, 610072, China.
² Department of Gastrointestinal Surgery, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan Province, 610072, China.
³ Institute of Neurology, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610072, China.
⁴ Department of Gastrointestinal Surgery, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan Province, 610072, China; Institute of Neurology, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610072, China.
⁵ Institute of Neurology, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610072, China. Electronic address: lyang@uestc.edu.cn.
⁶ Department of Gastrointestinal Surgery, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan Province, 610072, China; Clinical Immunology Translational Medicine Key Laboratory of Sichuan Province, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan Province, 610072, China. Electronic address: gzhao@uestc.edu.cn.

PMID: 37121553
DOI: 10.1016/j.imlet.2023.04.008

Abstract

Induced regulatory T cell (iTregs) can be generated in vitro. Thus, iTregs-based therapeutics are receiving increased attention for their potential to treat autoimmune diseases and prevent transplant rejection. However, iTregs fail to maintain FoxP3 expression and suppressive activity, which limits their clinical application. Increasing lines of evidence suggest that methyltransferase-like 14 (METTL14), a critical component of the m6A writer complex, regulates the stability and function of the Treg cells. However, beyond meeting the epigenetic modification of Treg cells, whether Mettl14 plays a role in the fate determination of iTregs is unclear. Here, we systemically investigated the potential function of METTL14 in iTregs differentiation and regulatory activity. In our study, iTregs were generated from CD4⁺ naïve T cells under iTreg-polarizing conditions, we found that the expression of METTL14 was increased in iTregs compared with CD4⁺naïve T cells. Subsequently, the expression of METTL14 was knocked down by siRNA-METTL14 interference in CD4⁺ naïve T cells and cultured under iTreg-polarizing conditions. According to the results, Mettl14 deficiency resulted in the disruption of iTregs differentiation evidenced by the limited FoxP3 expression. Meanwhile, inflammatory cytokines such as IFN-γ and IL-17a were upregulated in cultured iTregs. We next determined the functional change in METTL14-deficient iTregs. The results of the colitis development in Rag1^-/- mice and CFSE assays revealed that loss of METTL14 significantly compromised the suppressive function of iTregs in vivo and in vitro. We further checked the altered signaling pathway in METTL14-deficient iTregs. We found that reduced METTL14 leads to activation of the mTOR pathway with increased p-mTOR and p-p70S6K, which are known to modulate the suppressive function of iTregs. In conclusion, our study revealed that Mettl14 plays a critical role in the development and suppressive function of iTregs in vitro and could thus serve as a regulatory element for stabilizing iTregs in cell-based therapy.

Keywords: Differential; N6-methyladenosine; Suppressive function; iTregs; mTOR.

Publication types

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

MeSH terms

Animals
Cell Differentiation
Forkhead Transcription Factors / genetics
Mice
Signal Transduction*
T-Lymphocytes, Regulatory*
TOR Serine-Threonine Kinases / metabolism

Substances

Forkhead Transcription Factors
Foxp3 protein, mouse
TOR Serine-Threonine Kinases
mTOR protein, mouse
Mettl14 protein, mouse