# The double-edged sword of regulatory T cells in MASLD: from inflammation control to fibrosis promotion

**Authors:** So Eun Lee, Min Gi Jo, Sang Won Park, Hye Jung Kim, Seung Pil Yun, Jong-Won Kim

PMC · DOI: 10.1080/19768354.2026.2630463 · Animal Cells and Systems · 2026-02-16

## TL;DR

This paper reviews how regulatory T cells can both reduce liver inflammation and worsen fibrosis in liver diseases linked to metabolic issues.

## Contribution

The paper highlights the dual and context-dependent roles of Tregs in MASLD and MASH, offering insights for stage-specific therapies.

## Key findings

- Regulatory T cells can suppress liver inflammation and injury.
- Tregs may promote fibrosis by activating hepatic stellate cells.
- Therapeutic strategies aim to modulate Tregs with both local and systemic considerations.

## Abstract

Metabolic dysfunction-associated steatotic liver disease (MASLD) and its advanced inflammatory subtype, metabolic dysfunction-associated steatohepatitis (MASH), are becoming increasingly prevalent liver disorders driven by complex interactions between metabolic stress, immune dysregulation, and fibrotic remodeling. Regulatory T cells (Tregs), traditionally recognized for their immunosuppressive functions, have emerged as key modulators of hepatic inflammation, fibrosis, and systemic metabolic balance. While Tregs can suppress pro-inflammatory immune responses and mitigate liver injury, accumulating evidence highlights their paradoxical roles in liver fibrosis, including the promotion of hepatic stellate cell activation and profibrotic remodeling. This review critically examines the dual and context-dependent roles of Tregs in MASLD and MASH, emphasizing implications for therapeutic intervention. Additionally, we discuss current preclinical strategies aimed at modulating Treg abundance and function, highlighting the challenges and opportunities associated with developing stage-specific therapeutic approaches that consider not only local hepatic effects but also potential systemic metabolic consequences.

## Linked entities

- **Diseases:** Metabolic dysfunction-associated steatotic liver disease (MONDO:0013209), Metabolic dysfunction-associated steatohepatitis (MONDO:0007027)

## Full-text entities

- **Genes:** Tgfb1 (transforming growth factor, beta 1) [NCBI Gene 21803] {aka TGF-beta1, TGFbeta1, Tgfb, Tgfb-1}, Cd247 (CD247 antigen) [NCBI Gene 12503] {aka 4930549J05Rik, A430104F18Rik, Cd3, Cd3-eta, Cd3-zeta, Cd3h}, Tnf (tumor necrosis factor) [NCBI Gene 21926] {aka DIF, TNF-a, TNF-alpha, TNFSF2, TNFalpha, Tnfa}, Ido1 (indoleamine 2,3-dioxygenase 1) [NCBI Gene 15930] {aka Ido, Indo}, Nr4a1 (nuclear receptor subfamily 4, group A, member 1) [NCBI Gene 15370] {aka GFRP1, Gfrp, Hbr-1, Hbr1, Hmr, N10}, Dcn (decorin) [NCBI Gene 13179] {aka DC, DSPG2, PG40, PGII, PGS2, SLRR1B}, Foxo1 (forkhead box O1) [NCBI Gene 56458] {aka Afxh, FKHR, Fkhr1, Foxo1a}, CD8A (CD8 subunit alpha) [NCBI Gene 925] {aka CD8, CD8alpha, IMD116, Leu2, p32}, Il33 (interleukin 33) [NCBI Gene 77125] {aka 9230117N10Rik, Il-33, Il1f11, NF-HEV}, Gzmb (granzyme B) [NCBI Gene 14939] {aka CCP-1/C11, CCP1, Ctla-1, Ctla1, GZB}, Il10 (interleukin 10) [NCBI Gene 16153] {aka CSIF, If2a, Il-10}, Ctla4 (cytotoxic T-lymphocyte-associated protein 4) [NCBI Gene 12477] {aka Cd152, Ctla-4, Ly-56}, Foxp3 (forkhead box P3) [NCBI Gene 20371] {aka JM2, scurfin, sf}, Entpd1 (ectonucleoside triphosphate diphosphohydrolase 1) [NCBI Gene 12495] {aka 2610206B08Rik, ATP-DPH, Cd39, E130009M23Rik, NTPDase-1}, Il1rl1 (interleukin 1 receptor-like 1) [NCBI Gene 17082] {aka DER4, Fit-1, Ly84, ST2L, St2, St2-rs1}, Gpbar1 (G protein-coupled bile acid receptor 1) [NCBI Gene 227289] {aka BG37, GPCR, GPR131, M-BAR, TGR5}, Klrg1 (killer cell lectin-like receptor subfamily G, member 1) [NCBI Gene 50928] {aka 2F1-Ag, MAFA, MAFA-L}, CD4 (CD4 molecule) [NCBI Gene 920] {aka CD4mut, IMD79, Leu-3, OKT4D, T4}, Ccr4 (C-C motif chemokine receptor 4) [NCBI Gene 12773] {aka C-C CKR-4, CHEMR1, Cmkbr4, LESTR, Sdf1r}, Spp1 (secreted phosphoprotein 1) [NCBI Gene 20750] {aka 2AR, Apl-1, BNSP, BSPI, Bsp, ETA-1}, Foxo3 (forkhead box O3) [NCBI Gene 56484] {aka 1110048B16Rik, 2010203A17Rik, FKHRL1, Fkhr2, Foxo3a}, Il2 (interleukin 2) [NCBI Gene 16183] {aka Il-2}, Ccr10 (C-C motif chemokine receptor 10) [NCBI Gene 12777] {aka C-C CKR-10, CC-CKR-10, CCR-10, Cmkbr9, Gpr2}, Cxcl15 (C-X-C motif chemokine ligand 15) [NCBI Gene 20309] {aka Il8, Scyb15, lungkine, weche}, Cd40 (CD40 antigen) [NCBI Gene 21939] {aka Bp50, GP39, HIGM1, IGM, IMD3, T-BAM}, Atf4 (activating transcription factor 4) [NCBI Gene 11911] {aka Atf-4, C/ATF, CREB-2, CREB2, TAXREB67}, Cxcl9 (C-X-C motif chemokine ligand 9) [NCBI Gene 17329] {aka CMK, Mig, MuMIG, Scyb9, crg-10}, Klf10 (Kruppel-like transcription factor 10) [NCBI Gene 21847] {aka EGR[a], Egral, Gdnfif, TIEG-1, Tieg, Tieg1}, Nt5e (5' nucleotidase, ecto) [NCBI Gene 23959] {aka 2210401F01Rik, 5'-NT, CD73, NT, Nt5, eNT}, Mapk8 (mitogen-activated protein kinase 8) [NCBI Gene 26419] {aka JNK, JNK1, Prkm8, SAPK1}, Pparg (peroxisome proliferator activated receptor gamma) [NCBI Gene 19016] {aka Nr1c3, PPAR-gamma, PPAR-gamma2, PPARgamma, PPARgamma2}, Il1b (interleukin 1 beta) [NCBI Gene 16176] {aka IL-1beta, Il-1b}, Areg (amphiregulin) [NCBI Gene 11839] {aka AR, Mcub, Sdgf}, Il17a (interleukin 17A) [NCBI Gene 16171] {aka Ctla-8, Ctla8, IL-17, IL-17A, Il17}, Cd86 (CD86 antigen) [NCBI Gene 12524] {aka B7, B7-2, B7.2, B70, CLS1, Cd28l2}, Nr4a2 (nuclear receptor subfamily 4, group A, member 2) [NCBI Gene 18227] {aka HZF-3, NOT, Nurr1, RNR-1, TINOR, TINUR}, Adora2a (adenosine A2a receptor) [NCBI Gene 11540] {aka A2AAR, A2aR, AA2AR, ARA2A}, Nr4a3 (nuclear receptor subfamily 4, group A, member 3) [NCBI Gene 18124] {aka CHN, CSMF, MINOR, NOR-1, Nor1, TEC}, Mir195a (microRNA 195a) [NCBI Gene 387190] {aka Mir195, Mirn195, mir-195a, mmu-mir-195, mmu-mir-195a}, Ffar2 (free fatty acid receptor 2) [NCBI Gene 233079] {aka GPCR43, Gpr43}, Mtor (mechanistic target of rapamycin kinase) [NCBI Gene 56717] {aka 2610315D21Rik, FRAP, FRAP2, Frap1, RAFT1, RAPT1}, Ccr6 (C-C motif chemokine receptor 6) [NCBI Gene 12458] {aka CC-CKR-6, CCR-6, Cmkbr6, KY411}, Tlr7 (toll-like receptor 7) [NCBI Gene 170743], Lep (leptin) [NCBI Gene 16846] {aka ob, obese}, Cd80 (CD80 antigen) [NCBI Gene 12519] {aka B71, Cd28l, Ly-53, Ly53, MIC17, TSA1}, Icos (inducible T cell co-stimulator) [NCBI Gene 54167] {aka AILIM, CCLP, CRP-1, H4, Ly115}, Ifng (interferon gamma) [NCBI Gene 15978] {aka IFN-g, If2f, Ifg}, Il2ra (interleukin 2 receptor, alpha chain) [NCBI Gene 16184] {aka CD25, Il2r, Ly-43}, Egfr (epidermal growth factor receptor) [NCBI Gene 13649] {aka 9030024J15Rik, Erbb, Errb1, Errp, Wa5, wa-2}, Itgae (integrin alpha E, epithelial-associated) [NCBI Gene 16407] {aka A530055J10, CD103, aM290, alpha-E1, alpha-M290}, Sell (selectin, lymphocyte) [NCBI Gene 20343] {aka CD62L, L-selectin, LAM-1, LECAM-1, LECAM1, Lnhr}, Cd4 (CD4 antigen) [NCBI Gene 12504] {aka L3T4, Ly-4}, Il6 (interleukin 6) [NCBI Gene 16193] {aka Il-6}, Batf (basic leucine zipper transcription factor, ATF-like) [NCBI Gene 53314] {aka B-ATF, SFA-2}
- **Diseases:** premature death (MESH:D003643), immune (MESH:D007154), IR (MESH:D007333), cytotoxicity (MESH:D064420), liver disorders (MESH:D017093), systemic (MESH:D015619), hepatic diseases (MESH:D056486), hepatic lipid accumulation (MESH:D011017), glucose dysregulation (MESH:D018149), hepatocellular carcinoma (MESH:D006528), immune dysregulation (OMIM:614878), polyendocrinopathy enteropathy X-linked (IPEX) syndrome (MESH:C580192), chronic (MESH:D002908), cirrhosis (MESH:D005355), adipose tissue inflammation (MESH:D007249), MASLD (MESH:D008107), hepatocyte injury (MESH:D014947), mitochondrial dysfunction (MESH:D028361), nonalcoholic fatty liver disease (MESH:D065626), hepatic fibrosis (MESH:D008103), obese (MESH:D009765), autoimmune disease (MESH:D001327), HCC (MESH:D005234), metabolic dysfunction (MESH:D008659), metabolic dysregulation (MESH:D021081)
- **Chemicals:** bile acids (MESH:D001647), FAO (-), ATRA (MESH:D014212), amino acids (MESH:D000596), butyrate (MESH:D002087), FA (MESH:D005227), ATP (MESH:D000255), AMP (MESH:D000249), fructose (MESH:D005632), pioglitazone (MESH:D000077205), resmetirom (MESH:C588408), lipid (MESH:D008055), LPS (MESH:D008070), diacylglycerols (MESH:D004075), tryptophan (MESH:D014364), ROS (MESH:D017382), SCFA (MESH:D005232), glucose (MESH:D005947), mevalonate (MESH:D008798), adenosine (MESH:D000241), fat (MESH:D005223), Lactate (MESH:D019344), thiazolidinedione (MESH:C089946), tricarboxylic acid (MESH:D014233), rapamycin (MESH:D020123), triglyceride (MESH:D014280), vitamin A (MESH:D014801), free fatty acid (MESH:D005230), kynurenine (MESH:D007737), ceramides (MESH:D002518), cholesterol (MESH:D002784)
- **Species:** Homo sapiens (human, species) [taxon 9606], Mus musculus (house mouse, species) [taxon 10090]
- **Mutations:** A2A

## Full text

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## Figures

4 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12912241/full.md

## References

121 references — full list in the complete paper: https://tomesphere.com/paper/PMC12912241/full.md

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Source: https://tomesphere.com/paper/PMC12912241