Human interleukin-19 and its receptor: a potential role in the induction of Th2 responses

• Published in: International Immunopharmacology 2004-05, Vol.4 (5), p.615-626
• Main Authors: Gallagher, Grant, Eskdale, Joyce, Jordan, William, Peat, Jon, Campbell, John, Boniotto, Michele, Lennon, Greig P, Dickensheets, Harold, Donnelly, Raymond P
• Format: Article
• Language: English
• Subjects: Humans; Induction; Interleukin-10 - metabolism; Interleukin-10 - physiology; Interleukin-19; Interleukins; Leukocytes, Mononuclear - immunology; Leukocytes, Mononuclear - metabolism; Receptors, Interleukin - metabolism; Th 2 response; Th2 Cells - immunology; Th2 Cells - metabolism
• ISSN: 1567-5769; 1878-1705
• DOI: 10.1016/j.intimp.2004.01.005

Interleukin-19 (IL-19) is a newly discovered member of the IL-10 family of ligands whose function is presently undefined. We recently described its cloning and initial characterization and in so doing, noted that the induction of IL-19 by LPS in human monocytes was down-regulated by interferon-gamma (IFN-γ) and up-regulated by IL-4. This preliminary observation led us to speculate that IL-19 may play a role in the Th1/Th2 system and we examined this hypothesis further. Our results suggested that IL-19 is able to influence the maturation of human T-cells. CD4+ T-cells resulting from SEB stimulation in the presence of IL-19 contained a higher proportion of IL-4 producing cells than those developing in the absence of IL-19. This observation was complimented by the observation that fewer IFN-γ cells accrued in the presence of IL-19, thereby suggesting that IL-19 altered the balance of Th1/Th2 cells in favour of Th2. Furthermore, in whole PBMC cultures, IL-19 up-regulated IL-4 and down-regulated IFNγ in a dose-dependent manner. These results are presented here in review format, in the context of an overall discussion of IL-19 and its receptor.