Table I.
Biological activity of cytokines affects T cell-associated thymic function.
| Author (year) | Name | Molecular weight (kDa) | Cell producers | Biological activity | (Refs.) |
|---|---|---|---|---|---|
| Coto et al (1992); Dalloul et al (1991) | IFN-γ | 17.1 | Activated T cells; Natural killer cells | Affects T-cell, B-cell, and macrophage differentiation and maturation | (36,37) |
| Nitta and Suzuki (2016); Galy et al (1990); Savino et al (2016) | IL-1 | 17.3; 17.5 | Thymic epithelial cells; Macrophages; Monocytes | Can act as a growth factor for thymocytes and promote thymocyte T cell activation, proliferation and differentiation; Members of the IL-1 family of receptors contain activators and suppressors of inflammation | (31,38,39) |
| Savino and Dardenne (2000); Muegge et al (1993) | IL-2 | 13–17 | Activated T cells | Promotes the development of Treg cells within the inner thymus; Promotes the activation of T cell proliferation, differentiation and cytokine productio | (40,41) |
| Bayer et al (2007); Varas et al (1997); Weist et al (2015); Meilin et al (1997) | IL-4 | 18–19 | Activated T cells | T cell growth factor | (42–45) |
| Zlotnik et al (1987); Shevach (2009); Barnes and Powrie (2009) | IL-6 | 19–28 | Monocytes; Macrophages; Fibroblasts; T cells; Endothelial cells; B cells | Promotes the development and maturation of thymocytes | (46–48) |
| Mittal and Roche (2009); Patel et al (1995) | IL-7 | 20–28 | Stromal cells; Keratinocytes Hepatocytes; Dendritic cells | Promotes differentiation of CD8+ T cells in the thymus; Maintains T cell proliferation | (49,50) |
| Meilin et al (1995); Baseta and Stutman (2000) | IL-9 | 14–25 | Activated T cells | T cell growth factor | (51,52) |
| Zúñiga-Pflücker et al (1995); Arzt et al (2000) | IL-12 | 75 | T cells | Maintains thymic integrity and function | (53,54) |
| Cohen-Kaminsky et al (1991); Wang et al (2016) | IL-17 | 34–52 | T lymphocytes | Activates CD4+ memory T lymphocytes; Produces Treg 17 cells | (55,56) |
| Shanley et al (2009); Dooley and Liston (2012); Kappler et al (1987) | IL-21 | 15–18 | Activated CD4 T cells | Treg 17 cells Promotes CD4 T cell differentiation; Reduces the Th17 pathway; Costimulates activated natural killer and CD8 lymphocytes; Desensitizes responding cells to the inhibitory effects of; Treg cells act as a switch for immunoglobulin G production in B cells | (57–59) |
| Xing and Hogquist (2012); Roberts et al (1990) | IL-22 | 17–22 | T helper 17 cells | Promotes thymic epithelial cells proliferation and survival; Affects T cell development | (60,61) |
| Kisielow et al (1988); Ramsdell and Fowlkes (1990); Howard et al (1999) | TGF-β | 12.5 | Activated T cells; Activated B cells | Inhibits the IL-1, IL-2 and IL-7-dependent proliferation of thymocytes | (62,63,67) |
| Wang et al (1994); Müller-Hermelink et al (1987); Gruver and Sempowski (2008) | TNF-α | 17–26 | Monocytes; Macrophages | Promotes T cells and B cell proliferation | (68–70) |
| Boyd (1932); Gruver et al (2007) | TSLP | 18.1 | Epithelial and dendritic cells | Promotes T helper 2 differentiation of naïve CD4 T cells; Activates natural killer T cells, basophils and other innate immune cells | (71,72) |
CD, cluster of differentiation; IFN, interferon; IL, interleukin; TGF-β, transforming growth factor β; TNF-α, tumor necrosis factor α; Treg, regulatory T; TSLP, Thymic stromal lymphopoietin.