Lactate supports Treg function and immune balance via MGAT1 effects on N-glycosylation in the mitochondria
Jinren Zhou, … , Ling Lu, Bruce R. Blazar
Jinren Zhou, … , Ling Lu, Bruce R. Blazar
Published September 12, 2024
Citation Information: J Clin Invest. 2024;134(20):e175897. https://doi.org/10.1172/JCI175897.
View: Text | PDF
Research Article Immunology Metabolism

Lactate supports Treg function and immune balance via MGAT1 effects on N-glycosylation in the mitochondria

Abstract

Current research reports that lactate affects Treg metabolism, although the precise mechanism has only been partially elucidated. In this study, we presented evidence demonstrating that elevated lactate levels enhanced cell proliferation, suppressive capabilities, and oxidative phosphorylation (OXPHOS) in human Tregs. The expression levels of Monocarboxylate Transporters 1/2/4 (MCT1/2/4) regulate intracellular lactate concentration, thereby influencing the varying responses observed in naive Tregs and memory Tregs. Through mitochondrial isolation, sequencing, and analysis of human Tregs, we determined that α-1,3-Mannosyl-Glycoprotein 2-β-N-Acetylglucosaminyltransferase (MGAT1) served as the pivotal driver initiating downstream N-glycosylation events involving progranulin (GRN) and hypoxia-upregulated 1 (HYOU1), consequently enhancing Treg OXPHOS. The mechanism by which MGAT1 was upregulated in mitochondria depended on elevated intracellular lactate that promoted the activation of XBP1s. This, in turn, supported MGAT1 transcription as well as the interaction of lactate with the translocase of the mitochondrial outer membrane 70 (TOM70) import receptor, facilitating MGAT1 translocation into mitochondria. Pretreatment of Tregs with lactate reduced mortality in a xenogeneic graft-versus-host disease (GvHD) model. Together, these findings underscored the active regulatory role of lactate in human Treg metabolism through the upregulation of MGAT1 transcription and its facilitated translocation into the mitochondria.

Authors

Jinren Zhou, Jian Gu, Qufei Qian, Yigang Zhang, Tianning Huang, Xiangyu Li, Zhuoqun Liu, Qing Shao, Yuan Liang, Lei Qiao, Xiaozhang Xu, Qiuyang Chen, Zibo Xu, Yu Li, Ji Gao, Yufeng Pan, Yiming Wang, Roderick O’Connor, Keli L. Hippen, Ling Lu, Bruce R. Blazar

×

Figure 5

XBP1s is elevated to promote the transcription of MGAT1 in TregN in the high lactate environment.

Options: View larger image (or click on image) Download as PowerPoint
XBP1s is elevated to promote the transcription of MGAT1 in TregN in the ...
(A) Potential TFs of MGAT1 were found in TRRUST and PROMO databases. (B) Only XBP1s promoted the transcription of MGAT1 using 2 MGAT1 primers Among 15 TFs. n = 3. (C) Relative luciferase value after the addition of different combinations of pGL3-Basic, pGL3-MGAT1-promoter, Pdc315-HA, and Pdc315-XBP1s to HEK293 cells detected by microplate reader. n = 3. (D) 2 pGL3-MGAT1-promoter mutant constructs were designed according to 2 predicted binding sites from the JASPAR website. (E) Relative luciferase value after the addition of 2 pGL3-MGAT1-promoter Mutant constructs to HEK293 cells detected by a microplate reader. n = 3. (F) Expression of XBP1s in TregN in 4 groups for 48 hours by Western blot: control (ctrl), Toyocamycin, lactate, and Toyocamycin with lactate. n = 3. (G) OCR of TregN in 4 groups in 4 groups: Jurkat with lactate, Jurkat with lactate and Toyocamycin, MGAT1 knockdown Jurkat with lactate, and MGAT1 knockdown Jurkat with lactate and Toyocamycin. n = 3. Data are represented as mean ± SEM. 2-tailed Student’s t test (B, C, and E) or 1-way ANOVA (F and G). *P < 0.05, **P < 0.01, ***P < 0.001.