Detection of IL-9 producing T cells in the PBMCs of allergic asthmatic patients

Abstract

BackgroundInterleukin-9 (IL-9) was reported as an active participant in the pathogenesis of allergic asthma. This study aimed to investigate the major source ofIL-9 and its effect on interferon γ (IFN-γ) and immunoglobulin (Ig) secretion by B cells.MethodsWe isolated peripheral blood mononuclear cells from children with allergic asthma and healthy children. IL-9, IL-4 and IFN-γ expression were detected by ELISA, ELISpot and Flowcytometry. Expression of transcription factor PU.1 was measured by Western Blot. We evaluated the effect of IL-9 on B cell activation and Ig production.ResultsResults showed that compared with healthy children, levels of IL-9, IL-4 and PU.1 were elevated and levels of IFN-γ were lower in children with allergic asthma. IL-9-expressing CD4+ T cells did not co-express IL-4. Exogenous IL-9 inhibited IFN-γ production in a dose-dependent manner. Antigen-specific Th9 cells existed in children with house dust mite allergic asthma. IL-9 up-regulated expression of CD69 and CD25 on B cells and combination of IL-9 and IL-4 enhanced IgE production.ConclusionsIn conclusion, our results showed that Th9 cells may be the major source of IL-9 in children with allergic asthma. In these patients, IL-9 impairs IFN-γ production and synergistically promotes IL-4-induced IgE secretion.

Th9 cells in allergic diseases: A role for the microbiota?

“…Numerous studies, conducted both in humans and mice, recognized the role of IL‐9 and Th9 cells in airway allergic diseases, due to their contribution to airway inflammation. Research on human cohort material revealed an increased IL‐9 expression in bronchoalveolar lavage (BAL) from atopic asthma patients, which is in line with findings of increased IL‐9 production by CD4 T cells in peripheral blood mononuclear cells (PBMCs) from adult atopic asthma patients, as well as from atopic infants after allergen‐specific and polyclonal challenge . Importantly, a correlation between the frequencies of these IL‐9 producing cells and serum IgE levels was also observed in these asthma patients .…”

“…Research on human cohort material revealed an increased IL-9 expression in bronchoalveolar lavage (BAL) from atopic asthma patients, 32 which is in line with findings of increased IL-9 production by CD4 T cells in peripheral blood mononuclear cells (PBMCs) from adult atopic asthma patients, 33 as well as from atopic infants after allergen-specific and polyclonal challenge. 26,34 Importantly, a correlation between the frequencies of these IL-9 producing cells and serum IgE levels was also observed in these asthma patients. 33 Interestingly, using a mouse asthma model, it was proven that an anti-IL-9 antibody treatment inhibits airway inflammation by reducing the numbers of eosinophils and lymphocytes as well as the levels of type 2 cytokines IL-4 and IL-13 in the lungs.…”

“…Following the discovery of Th9 cells as a separate T helper subtype, these cells have emerged as important mediators of allergic inflammation. This potential role of Th9 cells in allergic diseases relates to the functional capacity of IL‐9 to stimulate IgE production by B cells, accumulate and activate mast cells, enhance eosinophil chemotaxis and stimulate mucin production in lung epithelial cells . Moreover, Th9 cells were recently discovered to express histamine H4 receptors, which might enhance the allergy promoting and inflammatory potential of these cells during allergic responses .…”

Expression of Cytokines and Chemokines as Predictors of Stroke Outcomes in Acute Ischemic Stroke

“…Antagonists to IL-5 have been produced for the treatment of severe asthma (58). Patients suffering from asthma have higher levels of IL-9 producing T-cells in their peripheral blood (59). While not targeted in a current treatment, systemically applied neutralizing antibodies reduces infarct (56).…”

Increased expression of interleukin‐9 in patients with allergic contact dermatitis caused by p‐phenylenediamine

“…A proinflammatory effect of IL-9 has been widely described in various allergic disorders, including asthma and allergic rhinitis. 30,31 The fact that the IL-9 level strongly correlates with the severity of the patch test reaction 22 suggests that IL-9 similarly promotes an inflammatory reaction in ACD. The proinflammatory role of IL-9 was previously confirmed in rodents, as ear swelling in Il9 −/− mice was less pronounced in a model of CHS caused by 2,4-dinitrofluorobenzene (DNFB) than in WT mice.…”