IL-5 production by resident mucosal allergen-specific T cells in an explant model of allergic rhinitis

IL-4/IL-13 Axis in Allergic Rhinitis: Elevated Serum Cytokines Levels and Inverse Association With Tight Junction Molecules Expression

The IL-4/IL-13 axis is involved in the pathogenesis of allergic rhinitis (AR). In this study, we investigated the serum cytokines levels of IL-4, IL-5, IL-6, and IL-13 in AR patients, and the transcript expression levels of their receptors (i.e. IL4R, IL5RA, IL6R, and IL13RA1) in nasal epithelial cells of AR patients versus non-allergic controls. Nasal epithelial cells and blood samples of non-allergic controls (n = 30) and AR patients (n = 30) were collected to examine mRNA expression and serum cytokines levels, respectively. Bioinformatics analyses of IL-4/IL-13 receptor heterodimer association with tight junction (TJ) and JAK/STAT signaling genes were conducted in a gene expression profiling (GEP) dataset (GSE44037) of AR patients (n = 12) and healthy controls (n = 6). Serum IL-4, IL-5, IL-6 or IL-13 levels, and IL13RA1 transcript expression were significantly higher in AR patients compared with non-allergic controls. IL-4 and IL-13 serum levels were positively correlated with IL13RA1 expression in AR patients but not in non-allergic controls. In the GEP dataset (GSE44037), six TJ (CLDN4, CLDN7, CLDN12, CLDN15, TJP1, and TJP2) genes’ expressions were negatively correlated, respectively, with IL-4Rα/IL-13Rα1 heterodimeric receptor expression in AR patients and not in control samples. These six TJ genes contributed to the significant enrichment of tight junction Gene Ontology (GO ID: 0070160). Lastly, STATs DNA binding motif analysis showed that each of these TJ genes contains STATs binding consensus sequence within intronic and intergenic regions. Our results suggest that increased IL-4/IL-13 serum cytokines levels may contribute to decreased TJs expression via IL-4Rα/IL-13Rα1 heterodimeric receptor in nasal epithelium of AR patients.

The Similarity of Biomarkers Level between Direct Nasal Fluid and Nasal Lavage Fluid in Allergic Rhinitis Patients

Background and Objectives: Biomarkers of allergic rhinitis (AR) have been studied; however, little is known regarding their practical application in the diagnosis of AR. Previous studies collected samples using saline lavage, nasal brushing, or nasal biopsy. To utilize nasal fluid as a diagnostic tool, we need to standardize the method of sample collection. Therefore, this study aimed to evaluate the difference in concentration of biomarkers depending on the method of nasal fluid collection.Materials and Method: Forty-five AR patients who had greater than moderate AR symptoms and who had positive results on skin prick test and serum-specific IgE tests were enrolled in this study. Nasal fluid was collected using the direct method or saline lavage method. The concentration of each biomarker was analyzed using enzyme-linked immunosorbent assay and the values compared.Results: Nasal fluid samples were collected directly from 14 patients and were collected via saline lavage in 31 patients. No significant differences were found in the median value of each biomarker between the two methods of nasal sample collection.Conclusion: Nasal fluid collection method does not significantly affect biomarker concentration.

Never Change a Flowing System? The Effects of Retrograde Flow on Isolated Perfused Lungs and Vessels

Retrograde perfusion may occur during disease, surgery or extracorporeal circulation. While it is clear that endothelial cells sense and respond to changes in blood flow, the consequences of retrograde perfusion are only poorly defined. Similar to shear stress or disturbed flow, retrograde perfusion might result in vasomotor responses, edema formation or inflammation in and around vessels. In this study we investigated in rats the effects of retrograde perfusion in isolated systemic vessels (IPV) and in pulmonary vessels of isolated perfused lungs (IPL). Anterograde and retrograde perfusion was performed for 480 min in IPV and for 180 min in the IPL. Perfusion pressure, cytokine levels in perfusate and bronchoalveolar lavage fluid (BALF), edema formation and mRNA expression were studied. In IPV, an increased perfusion pressure and initially also increased cytokine levels were observed during retrograde perfusion. In the IPL, increased edema formation occurred, while cytokine levels were not increased, though dilution of cytokines in BALF due to pulmonary edema cannot be excluded. In conclusion, effects of flow reversal were visible immediately after initiation of retrograde perfusion. Pulmonary edema formation was the only effect of the 3 h retrograde perfusion. Therefore, further research should focus on identification of possible long-term complications of flow reversal.

Increased expression of type 2 innate lymphoid cells in pediatric patients with allergic rhinitis

Type 2 innate lymphoid cells (ILC2s) are a newly identified group of innate immune cells. ILC2s promote features of allergic airway diseases through the secretion of Th2 type cytokines, including interleukin (IL)-4, IL-5 and IL-13. It remains unknown whether ILC2s aggregate in the peripheral blood. The present study examined the ILC2 levels in pediatric patients with allergic rhinitis (AR), and the correlation with the severity of clinical symptoms. Flow cytometry detected the ILC2s frequency in the peripheral blood of 12 healthy controls (HCs), 12 patients with AR sensitized only to house dust mites (HDM-AR), and 18 AR patients monosensitized to other antigens including weeds, animal danders and Blattella germanica, but not including HDM (non-HDM-AR). Clinical symptoms of AR were expressed according to the Total 5 Symptom Score (T5SS). The percentages of ILC2s in the peripheral blood were increased significantly in patients with HDM-AR and non-HDM-AR, compared with that in the HCs. A subgroup analysis of patients with AR indicated that the proportion of ILC2s was significantly increased in HDM-AR in comparison with that in non-HDM AR. Furthermore, there was a notable correlation between ILC2 levels and T5SS scores. ILC2s frequencies in PBMC were increased significantly in pediatric patients with AR, irrespective of the type of allergen. HDM may trigger more severe allergic reactions and an increase in the number of ILC2s. These discoveries indicate the unique function of ILC2 in AR and provide a potential therapeutic target.

Placenta-Derived Mesenchymal Stem Cells Reduce the Interleukin-5 Level Experimentally in Children with Asthma

Background: Mesenchymal stem cells (MSCs) have been investigated as a new treatment option for various diseases in recent years. However, the role of placenta-derived MSCs in children with asthma remains unclear. We assessed the effect of placenta-derived MSCs on T cell immune responses and cytokine IL-5 levels according to cultures in children with and without asthma. Study design: We enrolled children with and without asthma and recorded asthma symptom scores in the asthma group. Blood samples from children were collected to isolate peripheral blood mononuclear cells (PBMCs) and determine the total IgE level. The PBMCs were cultured in vitro with or without MSCs after stimulation with human anti-CD3 and anti-CD28 antibodies (0.5 μg/mL) to evaluate the effect of placenta-derived MSCs. Flow cytometry was performed to detect the activation and proliferation of CD4+ and CD8+ T cells. Pre- and post-culture IL-5 levels were measured in all samples. Results: The percentages of activation and proliferation among CD4+ and CD8+ T cells after coculture with MSCs were significantly lower in the asthma group (P < 0.05). IL-5 levels differed significantly between the PBMC culture and PBMC + MSC (P+S) coculture in the asthma group (P < 0.05). IL-5 levels differed significantly between the PBMC culture and P+S coculture in both the lower (P < 0.05) and higher (P < 0.0005) IgE asthma subgroups. IL-5 levels were also decreased in children with all severities of asthma (P < 0.05). Conclusions: Placenta-derived MSCs exerted an anti-IL-5 effect and reduced the IL-5 level in culture in different subgroups of children with asthma.

Silencing of CD86 in dendritic cells by small interfering RNA regulates cytokine production in T cells from patients with allergic rhinitis in vitro

The aim of the present study was to investigate the expression and role of the co‑stimulatory molecule T‑lymphocyte activation antigen CD86 (CD86) in dendritic cells (DCs) from the peripheral blood of patients with allergic rhinitis (AR) compared with those from healthy individuals. It was observed that mature DCs from the peripheral blood of patients with AR expressed high levels of the co‑stimulatory molecule CD86, but not CD80, compared with healthy control subjects. CD86 expression levels in DCs decreased significantly following transfection with siRNA in a lentiviral vector. Furthermore, the level of transforming growth factor‑β1 produced by T cells co‑cultured with DCs was significantly increased in the siRNA group, while interleukin (IL)‑4 and IL‑5 production was significantly decreased. The findings of the present study indicated that CD86 may play a pivotal role in the regulatory T cell/type 2 helper T cell imbalance in allergic inflammation.

Association of the polymorphisms in Th2 chemotaxis-related genes with the development and prognosis of autoimmune thyroid diseases

The prognosis of autoimmune thyroid disease (AITD) is difficult to predict. Th2 cells suppress the differentiation of Th1 and Th17 cells, which are associated with the prognosis of AITD. However, there are few reports as to whether Th2 chemotaxis-related genes, such as CRTH2 (chemoattractant receptor-homologous molecule expressed on Th2 cells), IL-25, TARC/CCL17 (Thymus and activation regulated chemokine/chemokine ligand 17) or STAT6 (Signal transducer and activator of transcription 6), affect the pathology of and/or susceptibility to AITD. Therefore, in this study, we genotyped functional SNPs in these genes to clarify the association of the genetic differences of genes related to Th2 differentiation and chemotaxis with the development and the prognosis of AITDs. The frequencies of the AA genotype of the CRTH2 rs545659 SNP and the CC genotype and the C allele of the CRTH2 rs634681 SNP were higher in patients with severe HD than in patients with mild HD. The frequency of the CC genotype in the TARC rs223828 SNP was higher in patients with intractable GD than in patients with GD in remission. In conclusion, the CRTH2 rs545659 and rs634681 SNPs were associated with the severity of HD, and the TARC/CCL17 rs223828 SNP was associated with the intractability of GD.

Characteristics of lower airway inflammatory changes in the minimal persistent inflammation of allergic rhinitis in mice

OBJECTIVE

This study aims to establish an experimental mouse model of minimal persistent inflammation (MPI), observe the features of inflammation and hyper-responsiveness of the upper/lower airways, and explore the relationship between inflammation and hyper-responsiveness in the upper/lower airways.

METHODS

Sixty-four female BALB/c mice were randomly divided into four groups: allergic rhinitis (AR) group as positive control, MPI group, negative control group and blank control group. Mice were given high and low-concentrated ovalbumin solution after basic and intensive sensitization to establish AR model and MPI model. Nasal mucosa and lung tissues were stained to observe eosinophil infiltration, goblet cell hyperplasia, and expression of intercellular adhesion molecule 1 (ICAM-1). Airway hyper-responsiveness was assessed. Levels of specific immunoglobulin E (sIgE), interleukin (IL)-4 and IL-5 in peripheral blood, nasal lavage fluid (NLF), and bronchoalveolar lavage fluid (BALF) were detected by Enzyme-linked immunosorbent assay.

RESULTS

The eosinophil infiltration and expression of ICAM-1 on nasal mucosa and in lung tissues in the AR and MPI groups were significantly elevated compared to control groups. Goblet cells count increased only in the nasal mucosa and not in lung tissues. Eosinophil and neutrophil count of NLF and BALF in the AR and MPI groups increased significantly compared to control groups. Level of IL-4 did not increase significantly, but sIgE and IL-5 did.

CONCLUSIONS

Mice in the MPI status exhibits lower airway inflammation and hyper-responsiveness with increase in eosinophil count, goblet cells, ICAM-1, IL-4, and IL-5. These results provide further evidence for the importance of MPI of AR in lower airway diseases.

Developments in the field of clinical allergy in 2015 through the eyes of Clinical and Experimental Allergy

In the second of two papers, we describe developments in the field of clinical allergy as documented by Clinical and Experimental Allergy in 2015. Epidemiology, clinical allergy, asthma and rhinitis are all covered.

Differential gene network analysis for the identification of asthma-associated therapeutic targets in allergen-specific T-helper memory responses

BACKGROUND

Asthma is strongly associated with allergic sensitization, but the mechanisms that determine why only a subset of atopics develop asthma are not well understood. The aim of this study was to test the hypothesis that variations in allergen-driven CD4 T cell responses are associated with susceptibility to expression of asthma symptoms.

METHODS

The study population consisted of house dust mite (HDM) sensitized atopics with current asthma (n = 22), HDM-sensitized atopics without current asthma (n = 26), and HDM-nonsensitized controls (n = 24). Peripheral blood mononuclear cells from these groups were cultured in the presence or absence of HDM extract for 24 h. CD4 T cells were then isolated by immunomagnetic separation, and gene expression patterns were profiled on microarrays.

RESULTS

Differential network analysis of HDM-induced CD4 T cell responses in sensitized atopics with or without asthma unveiled a cohort of asthma-associated genes that escaped detection by more conventional data analysis techniques. These asthma-associated genes were enriched for targets of STAT6 signaling, and they were nested within a larger coexpression module comprising 406 genes. Upstream regulator analysis suggested that this module was driven primarily by IL-2, IL-4, and TNF signaling; reconstruction of the wiring diagram of the module revealed a series of hub genes involved in inflammation (IL-1B, NFkB, STAT1, STAT3), apoptosis (BCL2, MYC), and regulatory T cells (IL-2Ra, FoxP3). Finally, we identified several negative regulators of asthmatic CD4 T cell responses to allergens (e.g. IL-10, type I interferons, microRNAs, drugs, metabolites), and these represent logical candidates for therapeutic intervention.

CONCLUSION

Differential network analysis of allergen-induced CD4 T cell responses can unmask covert disease-associated genes and pin point novel therapeutic targets.

Characterization of Regulatory T-Cell Markers in CD4+ T Cells of the Upper Airway Mucosa

CD4+ T regulatory cells (Tregs) comprise a heterogeneous population of cells the regulate immune responses and prevent autoimmunity. Most reports on human Tregs are derived from studies of peripheral blood, although Tregs mainly exert their functions in the periphery. Here we performed a detailed analysis of Tregs in the human upper airway mucosa under non-inflammatory conditions, and found that 10% of all CD4+ T cells expressed the transcription factor FOXP3 and the memory marker CD45RO, as well as high levels of CTLA-4. The majority of FOXP3+CD4+ T cells co-expressed the transcription factor Helios and produced very little cytokines, compatible with being thymus-derived Tregs. FOXP3+Helios-CD4+ T cells were more heterogeneous. A mean of 24% produced the immunomodulatory cytokine IL-10, whereas a large fraction also produced IL-2, IFN-μ or IL-17. A significant population (6%) of FOXP3-negative T cells also produced IL-10, usually in combination with IFN-μ. Together, we found that CD4+ T cells in the upper airways differed functionally from their counterparts in peripheral blood, including higher expression of IL-10. Moreover, our findings suggest that several subsets of CD4+ T cells with functionally distinct regulatory properties reside in the upper airway mucosa which should be taken into account when targeting Tregs for therapy.