Targeting Glutamine Metabolism Ameliorates Autoimmune Hepatitis via Inhibiting T Cell Activation and Differentiation

Abstract

BackgroundAutoimmune hepatitis (AIH) is mediated by a cascade of T cell-mediated events directed at liver cells and persistent inflammation within the liver can eventually result in liver cirrhosis. Targeting glutamine metabolism has an impact on T cell activation and differentiation. However, the effect of glutamine metabolism blocking upon AIH remains unknown. We use glutaminase antagonist 6-diazo-5-oxo-L-norleucine (DON) for in vitro assays and its prodrug 2-(2-amino-4-methylpentanamido)-DON (JHU083) for in vivo assays to investigate the potential therapeutic effect and molecular mechanism of glutamine metabolism blocking in an AIH murine model.MethodsAIH mice were treated with JHU083 or vehicle before concanavalin A (ConA) administration, and disease severity was examined. Then activation and differentiation [including Th1/Th17 cells and cytotoxic T lymphocytes (CTL)] of T cells from Vehicle-WT, JHU083-AIH and Vehicle-AIH mice were tested. Furthermore, in vitro T cell activation and differentiation were measured using separated splenocytes stimulated with ConA with or without DON. The activation and differentiation of T cells were tested using flow cytometry, qRT-PCR and ELISA. Phosphorylation level of mammalian target of rapamycin (mTOR) and 70 kDa ribosomal protein S6 kinase (P70S6K) were examined by western blotting.ResultsJHU083 and DON significantly suppressed the activation of T cells and inhibited the differentiation of Th1/Th17 cells and CTL in vivo and in vitro. Besides, we demonstrated that glutamine metabolism blocking inhibited T cells activation and differentiation through decreasing the mRNA expression of amino acid transporter solute carrier family 7 member 5 (SLC7A5) and mitigating the activation of mTOR signaling.ConclusionsWe proved that targeting glutamine metabolism represents a potential new treatment strategy for patients with AIH and other T cell-mediated disease. Mechanistically, we demonstrated that glutamine metabolism blocking inhibits T cells activation and suppresses the differentiation of Th1/Th17 cells and CTL.

Targeting glutamine metabolism in hepatic stellate cells alleviates liver fibrosis

“…The role played by glutamine metabolism, in which GDH is particularly important, has not been extensively characterized. Reprogramming of energy metabolism is important to liver disease [ 13 , 24 ]. Our study deeply explored the process of liver fibrosis to determine whether it was significantly slowed after GDH inhibition both in vitro and in vivo.…”

Unlocking the potential of T‐cell metabolism reprogramming: Advancing single‐cell approaches for precision immunotherapy in tumour immunity

“…The dual effect of adequate glutamine suggests that glutamine metabolism‐modulating adjuvants must be administered at a dosage within a clear time window. First, glutamine metabolic homeostasis is critical for T‐cell protein production and immunological activity 163 . By antagonising Gl‐induced hydrolysis of glutamine, JHU083 treatment enhances OXPHOS in Th1 and CD8+ Teff cells to prevent apoptosis and autophagy after oxidative stress is increased, and in combination with the EGFR peptide vaccine (EVax), this treatment may promote long‐term immunity 25 .…”

“…First, glutamine metabolic homeostasis is critical for T‐cell protein production and immunological activity. 163 By antagonising Gl‐induced hydrolysis of glutamine, JHU083 treatment enhances OXPHOS in Th1 and CD8+ Teff cells to prevent apoptosis and autophagy after oxidative stress is increased, and in combination with the EGFR peptide vaccine (EVax), this treatment may promote long‐term immunity. 25 Because Teffs lack well‐balanced effector functions, their infiltration into a setting characterised by KRAS , STK11/Lkb1 , KEAP1 and other oncogene mutant‐bearing advanced lung adenocarcinomas is severely reduced, and the rate of glutamine uptake by tumour cells is significantly increased.…”

The essential role of glutamine metabolism in diabetic cardiomyopathy: A review

“…[89] Moreover, inflammatory T cell responses have been associated with increased glutamine uptake, and blocking amino acid transporters such as adaptor protein caspase-1 recruitment domain amino acid transporter-2 and SLC7A5 can impair the induction of helper T cell 1 and helper T cell 17 cells while weakening T cell activation. [90,91] Additionally, AKG can act as a regulator of CD4(+) T cell differentiation, promoting the differentiation of naïve CD4(+) T cells into TH1 cells rather than Treg cells. Reducing extracellular glutamine levels can decrease intracellular AKG levels, favoring Treg cell differentiation.…”