Table 1. The mechanisms of action and therapeutic studies of Treg cells in lung diseases.
| Disease | Type of Treg cells | Main way | Main profile | Outcome | Reference |
|---|---|---|---|---|---|
| Asthma | CD4+ Treg cells, Foxp3+ Treg cells | TGF-β, IL-10, DLL4-Notch signalling pathway | ↓ ILC2, Th1 cells, Th2 cells, Th17 cells, Granulocytes | Inhibition | [153,158–162] |
| ARDS | Foxp3+ Treg cells | TGF-β, IL-10 | ↓ Lung pyroptosis, Th17 cells | Inhibition | [168,170,171,175] |
| IPF | CD4+Foxp3+ Treg cells | TGF-β | ↑ TGF-β1 | Early: Promotion | [174,181] |
| ↓ Th17 cells, CXCL10, Fibrosis | Late stage: Inhibition | ||||
| COPD | Foxp3+ Treg cells | TGF-β, IL-10 | ↓ HIF-1α, TNF-α, IL-1β, IL-17A, RORγt | Inhibition | [13,34,169,184] |
| CF | Foxp3+ Treg cells | TGF-β, IL-10 | ↓ IL-6, IL-8, IL-17A | Inhibition | [186,193] |
| Lung cancer | CD4+Foxp3+ Treg cells, CD25+ Treg cells | TGF-β, IL-10 | ↑ HIF-1α, CTLA4, CD39, GITR, B7H1, IFN-γ, CXCL13 | Promotion | [17,199,202–204,208–210,212–215] |
| ↓ CD8+ T cells, NK cells, IL-2 | |||||
| Bronchitis | Nrp-1+ Treg cells | TGF-β, IL-10 | ↑ IL-35, Glentiy-1 | Inhibition | [161,235,236,322–325] |
| ↓ IL-17, TIM-3, Macrophages, MHC class II molecules | |||||
| Pneumonia | Foxp3+CD39+ Treg cells | TGF-β, IL-10, IL-35 | ↑ EGF, BLIMP1 | Inhibition | [240,243,245,247,252,258] |
| ↓ CD4+ and CD8+ T cells, B cells, DCs, NK cells, Neutrophils, Eosinophils | |||||
| Pulmonary embolus | CD4+Foxp3+ Treg cells | TGF-β | ↑ SPARC, Monocytes | Inhibition | [264] |
Abbreviations: ARDS, acute respiratory distress syndrome; BCL6, B-cell lymphoma 6; BLIMP1, B-lymphocyte-induced maturation protein 1; CF, cystic fibrosis; COPD, chronic obstructive pulmonary disease; CTLA4, cytotoxic T-lymphocyte-associated protein 4; CXCL10, C-X-C motif chemokine ligand 10; CXCL13, C-X-C motif chemokine ligand 13; DC, dendritic cells; DLL4, delta-like 4; EGF, epidermal growth factor; GITR, glucocorticoid-induced tumour necrosis factor receptor; HIF-1α, hypoxia-inducible factor 1α; IFN-γ, interferon-γ; IL-1β, interleukin-1β; IL-10, interleukin-10; IL-17A, interleukin 17A; IL-35, interleukin-35; ILC2, Type 2 innate lymphocytes; IPF, idiopathic pulmonary fibrosis; MHC, major histocompatibility complex; NK, natural killer; SPARC, scalable processor architecture; TGF-β, transforming growth factor β; Th1, Type 1 T helper; Th2, Type 2 T helper; Th17, Type 17 T helper; TIM-3, T-cell immunoglobulin and mucin domain-containing protein 3; TNF-α, tumor necrosis factor alpha.