Dermatophagoides-induced interleukin-10 production by peripheral blood lymphocytes from patients with asthma in remission

Chiropractic Therapy Modulated Gut Microbiota and Attenuated Allergic Airway Inflammation in an Immature Rat Model

Background

As a type of traditional Chinese massage, chiropractic therapy is applied to prevent and treat children with asthma in China. However, its mechanism of action is unclear. Allergic airway inflammation plays a key role in the occurrence and development of asthma, in which changes in gut microbiota are involved. The present study investigated the influence of chiropractic therapy on allergic airway inflammation (AAI) and gut microbiota in an immature rat model.

Material/Methods

Three-week-old male Sprague-Dawley rats were divided randomly into control (CN), AAI, and chiropractic (CP) groups. AAI and CP groups were sensitized and challenged with ovalbumin (OVA) to induce AAI. The CP group received chiropractic therapy during AAI modelling. AAI was assessed by cell counts in bronchoalveolar lavage fluid and HE staining of lung tissues. Plasma OVA-sIgE, IFN-γ, IL-4, and IL-10 levels were detected by ELISA. DNA extraction from feces samples was used for 16S rRNA gene sequencing and analyzed for gut microbiota by Quantitative Insights Into Microbial Ecology (QIIME).

Results

AAI group had significantly lower richness and diversity of gut microbiota along with Th2 response and allergic airway inflammation. Moreover, the AAI group had lower abundance of butyrate-producing bacterial taxa with more Lactobacillus. Chiropractic therapy significantly increased the richness and diversity of gut microbiota and increased butyrate-producing bacterial taxa and decreased Lactobacillus, along with attenuating Th2 response and allergic airway inflammation during AAI modelling.

Conclusions

Chiropractic therapy attenuated allergic airway inflammation and optimized gut microbiota in an immature rat model, which might promote the development of adult-like butyrogenic milieu, immunotolerance, and inflammation attenuation.

Ketamine Inhalation Ameliorates Ovalbumin-Induced Murine Asthma by Suppressing the Epithelial-Mesenchymal Transition

BACKGROUND Asthma accounts for 0.4% of all deaths worldwide, a figure that increases annually. Ketamine induces bronchial smooth muscle relaxation, and increasing evidence suggests that its anti-inflammatory properties might protect against lung injury and ameliorate asthma. However, there is a lack of evidence of the usefulness and mechanism of ketamine in acute asthma exacerbation. This study aimed to analyze the therapeutic effects and mechanism of action of ketamine on acute ovalbumin (OVA)-induced murine asthma. MATERIAL AND METHODS In vivo, BALB/c mice with OVA-induced asthma were treated with or without ketamine (25 or 50 mg/mL). Serum, lung sections, and mononuclear cell suspensions from the lung were collected for histological, morphometric, immunofluorescence, microRNA, quantitative polymerase chain reaction, regulatory T cell identification, cytokine, and Western blotting analyses. In vitro, bronchial epithelial cells were cultured to analyze the effect and mechanism of ketamine on epithelial-mesenchymal transition (EMT) and transforming growth factor-β (TGF-β) signaling. RESULTS The inhalation of ketamine 25 or 50 mg/mL markedly suppressed OVA-induced airway hyper-responsiveness and airway inflammation, significantly increased the percentage of CD4+CD25+ T cells, and significantly decreased OVA-induced up-regulation of TGF-β1 and the EMT. MiR-106a was present at higher amounts in OVA-induced lung samples and was suppressed by ketamine treatment. The in vitro results showed that TGF-β1-induced EMT was suppressed by ketamine via miR-106a level regulation. CONCLUSIONS Ketamine ameliorates lung fibrosis in OVA-induced asthmatic mice by suppressing EMT and regulating miR-106a level, while ketamine inhalation might be a new therapeutic approach to the treatment of allergic asthma.

Interleukin-10 and interleukin-5 balance in patients with active asthma, those in remission, and healthy controls

BACKGROUND

The immunological mechanisms of asthma remission remain unclear although several reports have suggested that balance between T helper (Th) 2 cytokines and regulatory cytokines is related.

OBJECTIVE

To study the balance between interleukin (IL) 10 and IL-5 in asthma clinical remission.

METHODS

We measured the numbers of IL-5 and IL-10 producing cells in peripheral blood mononuclear cells stimulated with mite antigen obtained from patients with active asthma (group A, n = 18), patients in clinical remission (group R, n = 15) and nonatopic healthy controls (group H, n = 14).

RESULTS

The numbers of IL-5 producing cells in groups A and R were significantly higher than in group H. The number of IL-5 producing cells was lower in group R than in group A, although the difference was not statistically significant. The number of IL-10 producing cells was higher in group R than in group A, although again the difference was not statistically significant. There was a significant difference in the number of IL-10 producing cells between groups A and H but not between groups R and H. The ratio of the number of IL-10 to IL-5 producing cells was highest in group H followed by groups R and A, and the differences were statistically significant for each pair of groups.

CONCLUSION

Our study suggests that the IL-10/IL-5 balance is related to clinical asthma. The balance differs between patients in clinical remission and healthy controls, suggesting that allergic inflammation may continue even after clinical asthma remission.

Enhanced cysteinyl-leukotriene type 1 receptor expression in T cells from house dust mite-allergic individuals following stimulation with Der p

In order to determine the potential for allergen to modulate T cell expression of the CysLT₁ receptor and responsiveness to leukotrienes, peripheral blood mononuclear cells from house dust mite-allergic or nonallergic individuals were incubated with D. pteronyssinus allergen (Der p). Baseline CysLT₁ expression was similar in both groups of donors, but Der p significantly enhanced CysLT₁ expression in CD4⁺ and CD8⁺ T cells of only allergic individuals and induced enhanced responsiveness of CD4⁺ T cells to LTD₄ in terms of calcium mobilisation. This effect was prevented by the CysLT₁ antagonist MK571. Der p also induced IL-4 and IL-10 production, and neutralizing antibody to IL-4 prevented both the enhanced CysLT₁ expression and the enhanced responsiveness of T cells to LTD₄ induced by Der p. In allergic individuals, Der p also induced T cell proliferation and a Th2-biased phenotype. Our data suggest that, in allergen-sensitized individuals, exposure to allergen can enhance T cell expression of CysLT₁ receptors through a mechanism involving IL-4 production. This, in turn, would induce CD4⁺ T cell responsiveness to cysteinyl-leukotrienes and Th2 cell activation.

Mechanisms of peripheral tolerance to allergens

The immune system is regulated to protect the host from exaggerated stimulatory signals establishing a state of tolerance in healthy individuals. The disequilibrium in immune regulatory vs effector mechanisms results in allergic or autoimmune disorders in genetically predisposed subjects under certain environmental conditions. As demonstrated in allergen-specific immunotherapy and in the healthy immune response to high-dose allergen exposure models in humans, T regulatory cells are essential in the suppression of Th2-mediated inflammation, maintenance of immune tolerance, induction of the two suppressive cytokines interleukin-10 and transforming growth factor-β, inhibition of allergen-specific IgE, and enhancement of IgG4 and IgA. Also, suppression of dendritic cells, mast cells, and eosinophils contributes to the construction of peripheral tolerance to allergens. This review focuses on mechanisms of peripheral tolerance to allergens with special emphasis on recent developments in the area of immune regulation.

Transforming growth factor-beta1 and IL-13 response to allergen predict steroid needs in asthmatic children

BACKGROUND

The remission of asthma, which is induced during specific immunotherapy (SIT) or appears spontaneously in children is not completely understood and predictors of this phenomenon are still undefined.

OBJECTIVE

To assess CD4(+)CD25(+)Foxp3(+) Treg cells and cytokine/proliferation response to allergen-specific stimulation of PBMC as predictors of steroid sparing effect of SIT and steroid dosage needs without SIT during 5 years of follow-up in asthmatic children.

METHODS

This is a 5-year long study of 32 asthmatic children, sensitive only to house dust mite (HDM). Eighteen children who had completed 5 years of HDM SIT - SIT group, and 14 children without SIT as a control group were studied. All patients had baseline clinical/immunological assessment; before and after observation the minimum effective ICS dose was defined and lung function was measured.

RESULTS

In children from SIT group minimum effective ICS dose was reduced more than in children from control group (median reduction 65% vs. 0%; p<0.001). Among patients in control group asthma severity was reduced after 5 years of observation in those who had at baseline higher TGF-beta1 and lower IL-13 answer to allergen stimulation of PBMC. Better response to 5 years immunotherapy was observed in those who had at baseline higher TGF-beta1 and lower proliferation answer to allergen stimulation of PBMC.

CONCLUSION

Similar processes may decide on both, SIT-induced and spontaneously appearing, reduction in asthma severity. Immunotherapy was much more effective than pharmacotherapy in our study. IL-13 overproduction may impede reduction of disease severity in asthmatic children independently from TGF-beta pathway.

Cow's milk allergy: a complex disorder

Cow's milk allergy (CMA) is a complex disorder. Numerous milk proteins have been implicated in allergic responses and most of these have been shown to contain multiple allergenic epitopes. There is considerable heterogeneity amongst allergic individuals for the particular proteins and epitopes to which they react, and to further complicate matters, allergic reactions to cow's milk are driven by more than one immunological mechanism. Finally, the incidence and dominant allergic mechanisms change with age, with IgE-mediated reactions common in infancy and non-IgE-mediated reactions dominating in adults. The complexity of CMA has lead to many public misconceptions about this disorder, including confusion with lactose intolerance and frequent self-misdiagnosis. Indeed, the prevalence of self-diagnosed CMA in the community is 10-fold higher than the clinically proven incidence, suggesting a sizable population is unnecessarily eschewing dairy products. Avoidance of dairy foods, whether for true or perceived CMA, carries with it nutritional consequences and the provision of appropriate nutritional advice is important. In this review, the epidemiology and natural course of CMA is discussed along with our current understanding of its triggers and immunological mechanisms. We examine current strategies for the primary and secondary prevention of allergic sensitization and the ongoing search for effective therapies to ultimately cure CMA.