# The Th17/Treg axis: a key to understanding and treating autoimmune disorders

**Authors:** Xiangrui Xie, Yang Liu, Huijing Li

PMC · DOI: 10.1515/biol-2025-1285 · 2026-03-05

## TL;DR

This paper explores how balancing Th17 and Treg cells can help treat autoimmune rheumatic diseases by reducing inflammation and improving treatment outcomes.

## Contribution

The paper highlights the Th17/Treg balance as a novel key mechanism in autoimmune rheumatic diseases and its potential for therapeutic modulation.

## Key findings

- Th17 and Treg cell imbalance is a key pathogenic mechanism in autoimmune rheumatic diseases.
- The percentages of Th17 and Treg cells correlate with disease severity and treatment response.
- Modulating the Th17/Treg balance offers a potential therapeutic strategy for autoimmune rheumatic diseases.

## Abstract

In autoimmune rheumatic diseases (ARDs), T cells mistakenly attack the body’s own joints, skin, blood vessels, and other tissues, leading to chronic inflammation and tissue damage. Among these, the immune balance between T helper 17 lymphocytes (Th17) and regulatory T lymphocytes (Treg) is a foundation for maintaining normal immune function in the human body. An immune imbalance between Th17 and Treg cells is one of the key pathogenic mechanisms in ARDs. The percentages of Th17 and Treg cells can serve as important indicators for the severity of autoimmune diseases and treatment response. Therefore, by studying the origin and function of Th17 and Treg cells as well as the cytokine microenvironment that regulates their differentiation, we aim to modulate the immune state by restoring cellular balance. This approach is particularly relevant in ARDs such as rheumatoid arthritis, Sjögren’s syndrome, systemic lupus erythematosus, scleroderma, and ankylosing spondylitis. It also summarizes the current clinical application of disease-modifying anti-rheumatic drugs in regulating the balance between Th17 and Treg cells, with the aim of providing guidance for clinical practice.

## Linked entities

- **Diseases:** rheumatoid arthritis (MONDO:0008383), systemic lupus erythematosus (MONDO:0007915), scleroderma (MONDO:0005100), ankylosing spondylitis (MONDO:0005306)

## Full-text entities

- **Genes:** RORA (RAR related orphan receptor A) [NCBI Gene 6095] {aka IDDECA, NR1F1, ROR1, ROR2, ROR3, RORa1}, PIK3CB (phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit beta) [NCBI Gene 5291] {aka P110BETA, PI3K, PI3KBETA, PIK3C1}, IL17F (interleukin 17F) [NCBI Gene 112744] {aka CANDF6, IL-17F, ML-1, ML1}, SGK1 (serum/glucocorticoid regulated kinase 1) [NCBI Gene 6446] {aka SGK}, IL7 (interleukin 7) [NCBI Gene 3574] {aka IL-7, IMD130}, CD4 (CD4 molecule) [NCBI Gene 920] {aka CD4mut, IMD79, Leu-3, OKT4D, T4}, IL2 (interleukin 2) [NCBI Gene 3558] {aka IL-2, TCGF, lymphokine}, JAK2 (Janus kinase 2) [NCBI Gene 3717] {aka JTK10}, SOCS3 (suppressor of cytokine signaling 3) [NCBI Gene 9021] {aka ATOD4, CIS3, Cish3, SOCS-3, SSI-3, SSI3}, IFNG (interferon gamma) [NCBI Gene 3458] {aka IFG, IFI, IMD69}, IL21 (interleukin 21) [NCBI Gene 59067] {aka CVID11, IL-21, Za11}, IFNA1 (interferon alpha 1) [NCBI Gene 3439] {aka IFL, IFN, IFN-ALPHA, IFN-alphaD, IFNA13, IFNA@}, IL4 (interleukin 4) [NCBI Gene 3565] {aka BCGF-1, BCGF1, BSF-1, BSF1, IL-4}, TLR7 (toll like receptor 7) [NCBI Gene 51284] {aka IMD74, SLEB17, TLR7-like}, PTK2B (protein tyrosine kinase 2 beta) [NCBI Gene 2185] {aka CADTK, CAKB, FADK2, FAK2, PKB, PTK}, SMAD3 (SMAD family member 3) [NCBI Gene 4088] {aka HSPC193, HsT17436, JV15-2, LDS1C, LDS3, MADH3}, IL3 (interleukin 3) [NCBI Gene 3562] {aka IL-3, MCGF, MULTI-CSF}, IL17A (interleukin 17A) [NCBI Gene 3605] {aka CTLA-8, CTLA8, IL-17, IL-17A, IL17, ILA17}, LINC-ROR (long intergenic non-protein coding RNA, regulator of reprogramming) [NCBI Gene 100885779] {aka ROR, lincRNA-RoR, lincRNA-ST8SIA3}, CD86 (CD86 molecule) [NCBI Gene 942] {aka B7-2, B7.2, B70, BU63, CD28LG2, CD86 v6}, IL6 (interleukin 6) [NCBI Gene 3569] {aka BSF-2, BSF2, CDF, HGF, HSF, IFN-beta-2}, KLF13 (KLF transcription factor 13) [NCBI Gene 51621] {aka BTEB3, FKLF2, NSLP1, RFLAT-1, RFLAT1}, PIK3R1 (phosphoinositide-3-kinase regulatory subunit 1) [NCBI Gene 5295] {aka AGM7, GRB1, IMD36, p85, p85-ALPHA, p85alpha}, IL23A (interleukin 23 subunit alpha) [NCBI Gene 51561] {aka IL-23, IL-23A, IL23P19, P19, SGRF}, IL23R (interleukin 23 receptor) [NCBI Gene 149233] {aka PSORS7}, F3 (coagulation factor III, tissue factor) [NCBI Gene 2152] {aka CD142, TF, TFA}, CTLA4 (cytotoxic T-lymphocyte associated protein 4) [NCBI Gene 1493] {aka ALPS5, CD, CD152, CELIAC3, CTLA-4, GRD4}, IL17RA (interleukin 17 receptor A) [NCBI Gene 23765] {aka CANDF5, CD217, CDw217, IL-17RA, IL17R, IMD51}, MTOR (mechanistic target of rapamycin kinase) [NCBI Gene 2475] {aka FRAP, FRAP1, FRAP2, RAFT1, RAPT1, SKS}, TGFB1 (transforming growth factor beta 1) [NCBI Gene 7040] {aka CAEND1, CED, DPD1, IBDIMDE, LAP, TGF-beta1}, FOXO1 (forkhead box O1) [NCBI Gene 2308] {aka FKH1, FKHR, FOXO1A}, CD8A (CD8 subunit alpha) [NCBI Gene 925] {aka CD8, CD8alpha, IMD116, Leu2, p32}, JAK1 (Janus kinase 1) [NCBI Gene 3716] {aka AIIDE, JAK1A, JAK1B, JTK3}, CSF2 (colony stimulating factor 2) [NCBI Gene 1437] {aka CSF, GMCSF}, CD28 (CD28 molecule) [NCBI Gene 940] {aka IMD123, Tp44}, MIR19B1 (microRNA 19b-1) [NCBI Gene 406980] {aka C13orf25, MIR19B, MIRH1, MIRHG1, MIRN19B1, miR-19b-1}, IL12B (interleukin 12B) [NCBI Gene 3593] {aka CLMF, CLMF2, IL-12B, IMD28, IMD29, NKSF}, FOXP3 (forkhead box P3) [NCBI Gene 50943] {aka AIID, DIETER, IPEX, JM2, PIDX, XPID}, VTCN1 (V-set domain containing T cell activation inhibitor 1) [NCBI Gene 79679] {aka B7-H4, B7H4, B7S1, B7X, B7h.5, PRO1291}, CD80 (CD80 molecule) [NCBI Gene 941] {aka B7, B7-1, B7.1, BB1, CD28LG, CD28LG1}, IL15 (interleukin 15) [NCBI Gene 3600] {aka IL-15}, TLR9 (toll like receptor 9) [NCBI Gene 54106] {aka CD289}, RPTOR (regulatory associated protein of MTOR complex 1) [NCBI Gene 57521] {aka KOG1, Mip1}, IL6ST (interleukin 6 cytokine family signal transducer) [NCBI Gene 3572] {aka CD130, CDW130, GP130, HIES4, HIES4A, HIES4B}, TYK2 (tyrosine kinase 2) [NCBI Gene 7297] {aka IMD35, JTK1}, SMAD4 (SMAD family member 4) [NCBI Gene 4089] {aka DPC4, JIP, MADH4, MYHRS}, TRBV20OR9-2 (T cell receptor beta variable 20/OR9-2 (non-functional)) [NCBI Gene 6962] {aka CDR3, TCRBV20S2, TCRBV2O, TCRBV2S2O}, STAT1 (signal transducer and activator of transcription 1) [NCBI Gene 6772] {aka CANDF7, IMD31A, IMD31B, IMD31C, ISGF-3, STAT91}, IL6R (interleukin 6 receptor) [NCBI Gene 3570] {aka CD126, HIES5, IL-1Ra, IL-6R, IL-6R-1, IL-6RA}, IL22 (interleukin 22) [NCBI Gene 50616] {aka IL-21, IL-22, IL-D110, IL-TIF, ILTIF, TIFIL-23}, AKT1 (AKT serine/threonine kinase 1) [NCBI Gene 207] {aka AKT, PKB, PKB-ALPHA, PRKBA, RAC, RAC-ALPHA}, STAT3 (signal transducer and activator of transcription 3) [NCBI Gene 6774] {aka ADMIO, ADMIO1, APRF, HIES}, STAT4 (signal transducer and activator of transcription 4) [NCBI Gene 6775] {aka DPMC, SLEB11}, TNF (tumor necrosis factor) [NCBI Gene 7124] {aka DIF, IMD127, TNF-alpha, TNFA, TNFSF2, TNLG1F}, RORC (RAR related orphan receptor C) [NCBI Gene 6097] {aka IMD42, NR1F3, RORG, RZR-GAMMA, RZRG, TOR}, IL10 (interleukin 10) [NCBI Gene 3586] {aka CSIF, GVHDS, IL-10, IL10A, TGIF}, CSF3 (colony stimulating factor 3) [NCBI Gene 1440] {aka C17orf33, CSF3OS, GCSF}, JAK3 (Janus kinase 3) [NCBI Gene 3718] {aka JAK-3, JAK3_HUMAN, JAKL, L-JAK, LJAK}, MIR1205 (microRNA 1205) [NCBI Gene 100302161] {aka MIRN1205, hsa-mir-1205}, IL2RB (interleukin 2 receptor subunit beta) [NCBI Gene 3560] {aka CD122, IL15RB, IMD63, P70-75}
- **Diseases:** chronic pain (MESH:D059350), oral candidiasis (MESH:D002180), pulmonary interstitial fibrosis (MESH:D011658), interstitial lung disease (MESH:D017563), chronic (MESH:D002908), tissue damage (MESH:D017695), RA (MESH:D001172), Treg abnormalities (MESH:D000014), arthritis (MESH:D001168), conjunctivitis (MESH:D003231), immune-related diseases (MESH:D007154), LS (MESH:D012594), synovitis (MESH:D013585), Heligmosomoides polygyrus infection (MESH:D007239), osteoporosis (MESH:D010024), ARDs (MESH:D012216), joint damage (MESH:D007592), autoimmune disease (MESH:D001327), obese diabetic (MESH:D009765), skin rashes (MESH:D005076), AS (MESH:D013167), immune-mediated diseases (MESH:C567355), fatigue (MESH:D005221), cutaneous lupus erythematosus disease (MESH:D008178), fever (MESH:D005334), psoriasis (MESH:D011565), ankylosis (MESH:D000844), spinal deformity (MESH:D013122), psoriatic arthritis (MESH:D015535), SD (MESH:D012595), cartilage destruction (MESH:D002357), SLE (MESH:D008180), low back pain (MESH:D017116), morning stiffness (MESH:D048968), fibrosis (MESH:D005355), digital ulcers (MESH:C000721267), respiratory tract infections (MESH:D012141), fibrotic diseases (MESH:D004194), arthritis inflammation (MESH:D007249), arthritis-related dermatoses (MESH:D012871), diabetic (MESH:D003920), IL-2 deficiency (MESH:C565232), Principal Sjogren's syndrome (MESH:D012859), lupus nephritis (MESH:D008181), Tumors (MESH:D009369), swelling (MESH:D004487), CIA (MESH:D001169)
- **Chemicals:** Baricitinib (MESH:C000596027), Filgotinib (MESH:C584571), Chinese herbal (-), disulfide (MESH:D004220), alpha-Ketoglutarate (MESH:D007656), Ixekizumab (MESH:C549079), fatty acid (MESH:D005227), MTX (MESH:D008727), acetyl-CoA (MESH:D000105), sarilumab (MESH:C000592401), Secukinumab (MESH:C555450), Tocilizumab (MESH:C502936), upadacitinib (MESH:C000613732), salt (MESH:D012492), Tofacitinib (MESH:C479163)
- **Species:** Akkermansia muciniphila (species) [taxon 239935], Homo sapiens (human, species) [taxon 9606], Mus musculus (house mouse, species) [taxon 10090]
- **Mutations:** serine/threonine, rs7574865
- **Cell lines:** MRL-lpr — Mus musculus (Mouse), Stromal cell line (CVCL_B6HA)

## Figures

3 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12962647/full.md

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Source: https://tomesphere.com/paper/PMC12962647