Sources and effects of cytokines
| Cytokine | Sources | Important cellular and mediator effects |
| Th2/Tc2 cytokines | ||
| IL‐4 | Th2 | Increased eosinophil growth |
| Mast cells | Increased Th‐2; ↓ Th‐1 | |
| Basophils | Increased IgE | |
| Eosinophils | Increased mucin expression and goblet cells | |
| Increased VCAM‐1 expression on endothelial cells | ||
| IL‐5 | Th2 | Eosinophil maturation |
| Mast cells | Decreased apoptosis | |
| Eosinophils | Increased Th2 cells | |
| BHR | ||
| IL‐9 | Th2 | Increased activated T‐cells and IgE from B‐cells |
| Eosinophils | Increased mast cell growth and differentiation | |
| Increased mucin expression and goblet cells | ||
| Causes eosinophilic inflammation and BHR | ||
| IL-13 | Th2 | Activates eosinophils |
| Basophils | Decreased apoptosis | |
| Eosinophils | Increased IgE | |
| Natural killer cells | Increased mucin expression and goblet cells | |
| Induces emphysema and matrix metalloproteinases | ||
| Th1/Tc1 cytokines | ||
| IFN‐γ | Th1 | Decreased eosinophil influx after allergen |
| Natural killer cells | Decreased Th2 | |
| Activates endothelial cells, epithelial cells, alveolar macrophages/monocytes | ||
| Decreased IgE | ||
| Decreased BHR | ||
| IL‐2 | Th0 and Th1 | Eosinophilia in vivo |
| Eosinophils | Growth and differentiation of T‐cells | |
| Airway epithelial cells | ||
| IL-12 | B‐cells | Regulates Th1 differentiation |
| Monocytes/macrophages | Decreased expansion of Th2 | |
| Dendritic cells | Decreased IL‐4‐induced IgE synthesis | |
| Eosinophils | Stimulates natural killer cells and T‐cells to produce IFN‐γ | |
| IL-18 | Th1 cells | Induces IFN‐γ release from mitogen-stimulated blood mononuclear cells |
| Airway epithelium | Induces Th1 development together with IL-12 | |
| Causes release of IL‐8, MIP1‐1α and MCP‐1 from mononuclear cells | ||
| Proinflammatory | ||
| IL‐1 | Monocytes/macrophages | Increased adhesion to vascular endothelium; eosinophil accumulation in vivo |
| Fibroblasts | Growth factor for Th2 | |
| B‐cells | B‐cell growth factor; neutrophil chemoattractant; T‐cell and epithelial activation | |
| Th1 and Th2 | BHR | |
| Neutrophils | ||
| Endothelial cells | ||
| Airway epithelial cells | ||
| Airway SMCs | ||
| TNF‐α | Macrophages | Activates epithelium, endothelium, antigen-presenting-cells, monocyt monocytes/macrophages |
| T‐cells | BHR | |
| Mast cells | Increased IL‐8 from epithelial cells | |
| Airway epithelial cells | Increased matrix metalloproteinases from macrophages | |
| IL‐6 | Monocytes/macrophages | T‐cell growth factor |
| T‐cells | B‐cell growth factor | |
| B‐cells | Increased IgE | |
| Fibroblasts | ||
| Airway epithelial cells | ||
| IL‐8 | Monocytes/macrophages | Neutrophil chemoattractant and activator |
| Airway epithelial cells | Chemotactic for CD8+ T‐cells | |
| Airway SMCs | Activates 5‐lipoxygenase in neutrophils | |
| Eosinophils | Induces release of histamine and cys-beingLY leukotrienes from basophils | |
| IL-11 | Airway epithelial cells | B‐cell growth factor |
| Airway | Activates fibroblasts | |
| Fibroblasts | BHR | |
| Eosinophils | ||
| IL-16 | CD8+ T‐cells | Eosinophil migration |
| Epithelial cells | Growth factor and chemotaxis of CD4+ T‐cells | |
| Eosinophils | ||
| Mast cells | ||
| IL-17 | CD4+ T‐cells | T‐cell proliferation |
| Activates epithelia, endothelial cells, fibroblasts | ||
| Induces release of IL‐6, IL‐8 and GM-CSF | ||
| Neutrophil chemoattractant and activator | ||
| GM-CSF | T‐cells | Eosinophil apoptosis and activation; induces release of leukotrienes |
| Macrophages | Proliferation and maturation of haematopoietic cells | |
| Eosinophils | Endothelial cell migration | |
| Fibroblasts | BHR | |
| Endothelial cells | ||
| Airway SMCs | ||
| Airway epithelial cells | ||
| Inhibitory cytokines | ||
| IL-10 | Th2 | Decreased eosinophil survival |
| CD8+ T‐cells | Decreased Th1 and Th2 | |
| Monocytes/macrophages | Decreased monocyte/macrophage activation; ↑ B‐cell; ↑ mast cell growth | |
| Decreased BHR | ||
| IL-1RA | Monocytes/macrophages | Decreased Th2 proliferation |
| Decreased BHR | ||
| IL-18 | Dendritic cells | Enhances Th1 via IFN‐γ release |
| Monocytes | Releases IFN‐γ from Th1 | |
| Natural killer cells | Activates natural killer cells, monocytes | |
| Decreased IgE | ||
| Growth factors | ||
| PDGF | Macrophages | Fibroblast and airway smooth muscle proliferation |
| Airway epithelium | Release of collagen | |
| Fibroblasts | ||
| TGF‐β | Macrophages | Decreased T‐cell proliferation |
| Eosinophils | Blocks IL‐2 effects | |
| Airway epithelium | Fibroblast proliferation | |
| Chemoattractant for monocytes, fibroblasts, mast cells | ||
| Decreased airway smooth muscle proliferation |
Th: T‐helper cell
Tc: cytotoxic T‐cell
IL: interleukin
IgE: immunoglobulin E
BHR: bronchial hyperresponsiveness
IFN‐γ: interferon gamma
MIP‐1α: macrophage inflammatory factor 1α
MCP‐1: monocyte chemotactic protein‐1
SMC: smooth muscle cell
TNF‐α: tumour necrosis factor‐α
GM-CSF: granulocyte-macrophage colony-stimulating factor
IL-1RA: IL‐1 receptor antagonist
PDGF: platelet-derived growth factor
TGF‐β: transforming growth factor‐β
VCAM: vascular adhesion molecule