Abstract
Interleukin (IL) 9-producing helper T (Th) 9 cells play a major role in contributing immunity against extracellular pathogens. In addition, the role of Th9 cells was demonstrated in the pathogenesis of allergic, skin, and intestinal inflammation. The functions of Th9 cells were further extended in antitumor immune response, as Th9 cells were suggested to be potent antitumor Th cells. Given the pleotropic functions of IL-9 in various pathophysiological conditions, it is essential to understand the differentiation and stability of Th9 cells and other IL-9-producing T cells. In addition to Th9 cells, Th2 and Th17 cells as well as induced Foxp3+ regulatory T cells (iTregs) cells also produce IL-9, but how IL-9 production is regulated in these cell types is not yet clearly defined. Although Th2, Th9 and Th17 cells as well as iTregs develop in the presence of distinct differentiating factors, yet they all express IL-9 together with their own lineage specific cytokines. Here, in this review, we summarize the current understanding of signaling pathways that lead to the promotion of differentiation of Th9 cells and IL-9 induction in Th2 and Th17 cells, as well as in iTregs. We further discuss the transcriptional regulation of Th9 cells in context of Foxo1, as an essential transcription factor required for the development and functions of Th9 and other IL-9-producing T cells.
Highlights
Almost more than two decades ago, interleukin (IL)-9 was described as T cell growth factor, which was later categorized as one of the Th2 cytokine [1, 2]
We have reported that TGF-β1-induced induced Tregs (iTregs) express Il9 and other Th9-associated factors such as Batf, Irf4 and Spi1 and Klf2, a Foxo1 target gene, and inhibition of Foxo1 in iTregs leads to IL-9 suppression
Over the last one decade since the discovery of Th9 cells in 2008, an extensive array of signaling axis, transcription factors, and physiological functions that are involved in development and amplification of IL-9+ T cells have been unraveled
Summary
Immuno-Biology Laboratory, Center for Human Microbial Ecology, Translational Health Science and Technology Institute, Faridabad, India. Given the pleotropic functions of IL-9 in various pathophysio logical conditions, it is essential to understand the differentiation and stability of Th9 cells and other IL-9-producing T cells. Th2, Th9 and Th17 cells as well as iTregs develop in the presence of distinct differentiating factors, yet they all express IL-9 together with their own lineage specific cytokines. We further discuss the transcriptional regulation of Th9 cells in context of Foxo, as an essential transcription factor required for the development and functions of Th9 and other IL-9-producing T cells
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
