Interleukin-9 (IL-9) is a pleiotropic cytokine and was primarily studied in the context of T helper 2 (T<sub>H</sub>2)-associated immuno-pathological conditions such as asthma and parasitic infections.
The results show that the levels of Th9 cells and their cytokine IL-9 in the peripheral blood of mice with bronchial asthma are significantly increased, suggesting that Th9 cells play important roles in the pathogenesis of asthma.
Persistence of experimental asthma in ST2 KO mice was associated with an increase in levels of thymic stromal lymphopoietin (TSLP), IL-9, and IL-13, but not IL-5, in bronchoalveolar lavage fluid.
In order to ascertain whether it is a successful translation from bench to bedside, the biological features of IL-9 were evaluated and up-to-date information regarding the role of IL-9 in different experimental murine models and human asthma were summarized.
Cytokine-producing Th subsets including Th1 (IFN-γ), Th2 (IL-4, IL-5, IL-13), Th9 (IL-9), Th17 (IL-17), Th22 (IL-22), and T regulatory (IL-10) cells have all been suggested to play a role in the development of asthma.
This study shows for the first time that IL-9 is involved in EO homeostasis in CRSwNP and could explain the low benefit of anti-IL-5 therapy for some patients with asthma and nasal polyposis.
Subjects with the dominant genotype for these IL9 polymorphisms were more likely to report a severe asthma exacerbation if exposed to increased dust mite levels.
In simple AD patients and AD patients complicated by allergic rhinitis or asthma, there were no significant differences in the Th9 cell percentage, PU.1 and IL-9 expression levels between them.
We assessed the effects of IL-9, IL-13 and an IL-9/IL-13 combination, during differentiation of bronchial epithelial cells from normal (n = 6) and asthmatic (n = 8) children.
IL-9 targets cells of the lymphoid, myeloid and mast cell lineages, and is likely to contribute to the development of allergic and autoimmune diseases such as asthma, arthritis, multiple sclerosis and experimental autoimmune encephalomyelitis (EAE).
This assumption was initially confirmed by functional analyses showing that both IL-9 and Th2 cells play an important role in the pathogenesis of asthma, IgE class switch recombination, and resolution of parasitic infections.
Interleukin 9 (IL-9) has been implicated in mast cell-related inflammatory diseases, such as asthma, where vascular endothelial growth factor (VEGF) is involved.
CD4(+) T-helper type 2 (T(H)2) cells, characterized by their expression of interleukin (IL)-4, IL-5, IL-9 and IL-13, are required for immunity to helminth parasites and promote the pathological inflammation associated with asthma and allergic diseases.
In the present study, we examined the effect of IL-9 overexpression on the subepithelial fibrotic response, a feature of asthmatic remodeling, induced by chronic exposure to Alternaria alternata extract.
Other activities described for IL-9 support its contribution to asthma and its important role in helminthic infections, where a Th2 response can be protective and IL-9 enhances resistance or is responsible for elimination of the nematode.
There was slight increased interaction effect on asthma between transmission of allele 122 of IL-9 gene to offspring and who were exposed to the fur of pets (OR = 3.33, P = 0.047).