An eosinophil-Sos1-RAS axis licenses corticosteroid resistance in patients with allergic rhinitis.

BACKGROUND: Corticosteroid resistance (CR) is a serious disadvantage in treating many chronic inflammatory conditions. Eosinophils are the main inflammation cells in allergic reactions. Environmental pollution, such as PM2.5, is associated with the pathogenesis of allergic disorders. The objective of this study is to elucidate the mechanism by which the exposure to PM2.5 confers eosinophil CR status. METHODS: Patients with allergic rhinitis were recruited and assigned to corticosteroid sensitive (CS) and CR groups. Eosinophils were purified from nasal lavage fluids collected from patients with allergic rhinitis. A murine AR mouse model was developed with dust mite allergens and PM2.5 as the sensitization reagents. RESULTS: CR status was detected in about 60% eosinophil collected in patients with AR. Upon exposure to eosinophil activators, CS eosinophils released a large quantity of mediators, which was suppressed by the presence of steroids in the culture. CR eosinophils demonstrated resistance to steroidal therapy. RAS activation levels in eosinophils were higher in CR eosinophils than in CS eosinophils. Higher expression of the Son of sevenless-1 (Sos1) was detected in CR eosinophils, which formed a complex with RAS and glucocorticoidreceptor-α in CR eosinophils to prevent the binding between steroids and glucocorticoidreceptor-α. The presence of an Sos1 inhibitor dissociated glucocorticoid receptor-α from RAS/Sos1 complex, that restored the sensitivity to steroids in eosinophils. Administering the Sos1 inhibitor effectively attenuated the experimental allergic rhinitis. CONCLUSIONS: CR status was detected in approximately 1/3 eosinophils sampled from patients with allergic rhinitis. Sos1 was instrumental in the development and perseverance of CR in eosinophils. Sos1 inhibition restored sensitivity to steroids in CR eosinophils, which effectively reduced experimental allergic rhinitis.

Circadian rhythm disruption exacerbates Th2-like immune response in murine allergic airway inflammation.

BACKGROUND: Chronic jet lag (CJL)-induced circadian rhythm disruption (CRD) is positively correlated with an increased risk of allergic diseases. However, little is known about the mechanism involved in allergic rhinitis (AR). METHODS: Aberrant light/dark cycles-induced CRD mice were randomly divided into negative control (NC) group, AR group, CRD+NC group, and CRD+AR group (n = 8/group). After ovalbumin (OVA) challenge, nasal symptom scores were recorded. The expression of Occludin and ZO-1 in both nasal mucosa and lung tissues was detected by reverse transcription-quantitative polymerase chain reaction (RT-PCR) and immunohistochemical staining. The level of OVA-specific immunoglobulin E (sIgE) and T-helper (Th)-related cytokines in the plasma was measured by enzyme-linked immunosorbent assay (ELISA), and the proportion of Th1, Th2, Th17, and regulatory T cell (Treg) in splenocytes was evaluated by flow cytometry. RESULTS: The nasal symptom score in the CRD+AR group was significantly higher than those in the AR group with respect to eosinophil infiltration, mast cell degranulation, and goblet cell hyperplasia. The expression of ZO-1 and Occludin in the nasal mucosa and lung tissues in the CRD+AR group were significantly lower than those in the AR group. Furthermore, Th2 and Th17 cell counts from splenocytes and OVA-sIgE, interleukin 4 (IL-4), IL-6, IL-13, and IL-17A levels in plasma were significantly increased in the CRD+AR group than in the AR group, whereas Th1 and Treg cell count and interferon γ (IFN-γ) level were significantly decreased in the CRD+AR group. CONCLUSION: CRD experimentally mimicked CJL in human activities, could exacerbate local and systemic allergic reactions in AR mice, partially through decreasing Occludin and ZO-1 level in the respiratory mucosa and increasing Th2-like immune response in splenocytes.

Livin in synergy with Ras induces and sustains corticosteroid resistance in the airway mucosa.

Rationale: Corticosteroid resistance (CR) seriously affects the therapeutic effects of steroids on many chronic inflammatory disorders, including airway allergy. The mechanism of CR development is unclear. Recent research indicates that livin, an apoptosis inhibitor, is associated with the regulation in cell activities. This study investigates the role of livin in the inducing and sustaining CR in the airway mucosa. Methods: Nasal epithelial cells (NECs) were isolated from surgically removed nasal mucosal tissues of patients with allergic rhinitis (AR) and nasal polyps with or without CR. Differentially expressed genes in NECs were analyzed by the RNA sequencing. A CR mouse model was developed to test the role of livin in CR development. Results: The results showed that NECs of AR patients with CR expressed high levels of livin, that was positively correlated with the thymic stromal lymphopoietin (TSLP) expression and the high Ras activation status in NECs. Livin and Ras activation mutually potentiating each other in the inducing and sustaining the TSLP expression in NECs. TSLP induced eosinophils and neutrophils to express glucocorticoid receptor-ß (GRß). Eosinophils and neutrophils with high CRß expression were resistant to corticosteroids. Depletion of livin or inhibition of TSLP markedly attenuated CR and airway allergy. Conclusions: Livin facilitates CR development in the airways by promoting TSLP expression in epithelial cells and the GRß expression in eosinophils and neutrophils. Depletion of livin or inhibiting TSLP attenuates CR development and inhibits airway allergy, this has the translational potential to be used in the treatment of airway allergy.

Role of FcγRI in Antigen-Dependent Eosinophil Activation in Patients With Allergic Rhinitis.

BACKGROUND: The eosinophil (Eo) activation is a crucial factor evoking allergic rhinitis (AR) attacks; factors; the mechanism of triggering Eo activation remains to be further investigated. The interaction of antigen (Ag) and antibody plays a critical role in evoking allergy attacks. This study aims to elucidate the role of FcγRI, the high affinity receptor of IgG, in the Ag-mediated Eo activation. METHODS: Nasal lavage fluids (NLF) were collected from AR patients and healthy control (HC) subjects. Eos were isolated by flow cytometry cell sorting and analyzed by pertinent immunological approaches. RESULTS: Eos composed more than 60% of the cellular components in AR NLF. Exposure to specific Ags (sAgs) in the culture triggered Eos to release inflammatory mediators. High levels of FcγRI were detected on the surface of AR NLF Eos. Exposure to lipopolysaccharide markedly increased the FcγRI expression in naive Eos, which could be bound by Ag-specific IgG (sIgG) to form complexes on the surface of Eos; this made Eos at the sensitized status. Eos bore with the sIgG/FcγRI complexes could be activated upon exposure to sIgG in the culture; these Eos can be designated as Ag-specific Eos. Passive transfer of Ag-specific Eos resulted in profound AR response in mice upon sAg challenge. Depletion of FcγRI on Eos efficiently abolished AR response in mice. CONCLUSIONS: AR Eos express high levels FcγRI, that can be bound by sIgG to make Eos sensitized. Re-exposure to specific Ags can activate the sensitized Eos.

Probiotic extracts ameliorate nasal allergy by inducing interleukin-35-producing dendritic cells in mice.

BACKGROUND: The therapeutic efficacy of allergic rhinitis (AR) needs to be improved. Probiotics have immunoregulatory functions. In this study we evaluated the effects of protein extracts of probiotics in the amelioration of AR. METHODS: Extracts of Bifidobacterium infantis (EBI) were prepared by lysing the live probiotics. AR mice were developed to be used to evaluate the therapeutic efficacy of EBI. RESULTS: The results show that EBI induced interleukin (IL)-10-producing dendritic cells (DCs) via increasing IL-35 and signal transducer and activator of transcription 3 (STAT3) phosphorylation. IL-10-expressing DCs induced IL-10-producing B cells (B10 cells), with the latter showing immunosuppressive functions. After challenge with specific antigens, AR mice showed sneezing, nasal itch, and increases in serum-specific immunoglobulin E (IgE) and mouse mast cell protease-1; higher levels of T helper 2 (Th2) cytokines (IL-4, 67.17 ± 10.66; IL-5, 62.83 ± 9.70; IL-13, 51.00 ± 6.69, before treatment) in nasal mucosal protein extracts, which were significantly suppressed (IL-4, 27.00 ± 6.66; IL-5, 23.86 ± 4.53; IL-13, 25.67 ± 4.93, after treatment (p < 0.001) by administration with EBI nasal drops. CONCLUSION: EBI can suppress AR via inducing B10 cells. Thus, after carrying out required preclinical experiments and tests, EBI has the translational potential to be used in the treatment of AR and other allergic diseases.

Survivin facilitates T-helper 2-biased inflammation in the airway.

BACKGROUND: The biased T helper 2 (Th2) responses play a critical role in the pathogenesis of allergy. The underlying mechanism is not fully understood yet. Survivin can regulate multiple cellular activities. This study aims to elucidate the role of survivin in the development and maintenance of Th2 polarization. METHODS: CD4+ T cells were isolated from blood samples collected from patients with allergic asthma (AS) and HS control (HS) subjects. Mice carrying CD4+ T cells with survivin knockout (KO mice) were employed to test the role of survivin in the development of the biased Th2 responses. RESULTS: KO mice failed to induce airway allergy. Peripheral CD4+ T cells expressed survivin, which was higher in the AS group than that in the HS group. Naive CD4+ T cells with higher expression of survivin were prone to differentiating into Th2 cells. Survivin bound to the Il4 promoter in CD4+ T cells to enhance Il4 gene transcription. The expression of Fas was lower in CD4+ T cells of the AS group than that in the HS group. Overexpression of survivin suppressed the expression of Fas and impaired the activation-induced cell death (AICD) of CD4+ T cells. CONCLUSION: Survivin facilitates the development of biased Th2 polarization through promoting expression of interleukin 4 (IL-4) and impairing the AICD machinery of CD4+ T cells. To modulate the expression of survivin in CD4+ T cells has the translational potential in the treatment of allergic diseases.

[Application of image guided technique in rhino-orbital related endoscopic surgery].

Objective:To review retrospectively six cases of rhino-orbital related endoscopic surgeries aided by Fusion electromagnetic system,to explore the indications and clinical value of image guided technique in endonasal endoscopic surgery.Method:Retrospective research methods were used.In this study,six cases of nasal endoscopic sinus surgery using Fusion electromagnetic system were analyzed,including 1 nasal penetrating foreign body,2 optic nerve decompressions,1 orbital apex hemangioma,1 sieve frontal sinus cyst,1 intraorbital mass biopsy.The preparation time of navigation system,the accuracy of intraoperative positioning and surgical coherence,intraoperative and postoperative complications of surgery were recorded.Result:The average preparation time was(8.13 ± 1.858)min.In the navigation,the sinus ostium,orbital cardboard,skull base,optic nerve,internal carotid artery and other important structures can be accurately located in all patients,while registrations had been accurate within 1 mm.Six patients were successfully operated by image guided technique.There was no intracranial or intraorbital complications due to intraoperation error.Conclusion:Image guided technique allows for a truely microinvasive and accurate rhino-orbital related endoscopic surgeries.It requires less preoperative preparation time,has high surgical navigation accuracy,improves the surgical coherence and safety,and reduces the surgical complicationgs.However,as an auxiliary tool,it can not replace the surgeon's anatomical knowledge,surgical training and clinical experience.

[Differential gene expression profile in seasonal allergic rhinitis with and without asthma].

OBJECTIVE: To screen the differential expression gene profile in nasal mucosa of seasonal allergic rhinitis (SAR) and SAR with asthma, oligonucleotide microarray (Affymetrix HG-U133-plus2) was employed to analyze the changes of gene expressions with GeneSpring software. METHODS: Inferior turbinate mucosa was obtained from five SAR patients and four SAR with asthma patients. Total RNA was extracted from the nasal mucosal biopsies and pooled into one SAR control pool and one SAR with asthma patient pool, and biotin-labeled cRNA probes were hybridized with Affymetrix HG-U133-plus2 array. The hybridization results were confirmed by RT-PCR analysis. The analysis of differential expression profiles were performed by GeneSpring software 7.3. RESULTS: Out of 47,000 analysed transcripts, 1,900 genes were differentially expressed at least 2-fold in which 849 genes were up-regulated and 1,051 genes were down-regulated in nasal mucosa of SAR with asthma patients compared with that in SAR patients. These genes were involved in cell metabolism, gene transcription, cell proliferation, signal transduction, immune response, enzyme activity, transmembrane receptor activity, cytoskeletal protein binding, and many other aspects. Pathway analysis displayed 161 groups, of which including more than 20 genes were as follow: cytokine-cytokine receptor interaction, focal adhesion, cell adhesion molecules (CAMs), regulation of actin cytoskeleton, cell communication, gap junction, MAPK signaling pathway, calcium signaling pathway, leukocyte transendothelial migration, and purine metabolism. CONCLUSIONS: The data suggested that multigentic expression and regulation changes were involved in the development of SAR and SAR complicated with asthma, whose molecular mechanisms might be elucidated by identification of these differential genes.

[Preliminary investigation into the allergic rhinitis complicated with acute bacterial sinusitis in mice].

OBJECTIVE: To develop a mouse model of bacterial rhinosinusitis superposed on allergic rhinitis (AR), and to explore whether ongoing allergic rhinitis enhance the acute sinus infection and inflammation associated with Streptococcus pneumoniae (SP). METHODS: Fourty mice of C57BL6/J were randomly divided on average into 4 groups: A [ovalbumin (OVA) + SP], B [OVA + normal saline (NS)], C [phosphate buffered solution (PBS) + SP] and D (PBS + NS). (1) Group A and B were sensitized by intraperitoneal injection with 200 microl (10%) OVA on days 1 through 9, and exposed to OVA (6%) intranasally on days 10 through 17, to induce allergic inflammation. OVA was replaced with PBS in group C and D in the same way. (2) Subsequently, group A and C were inoculated with SP intranasally on day 13, and NS was used in group B and D. On the 6th day after inoculation, mice were killed. Blood was collected from the orbital venous sinus after anesthesia. The heads were embedded with paraffin and serial sections were followed and stained with hematoxylin-eosin and toluidine blue (0.5%) for histological analysis and inflammation cells count. The number of polymorphonuclear neutrophils (PMN) and eosinophils (EOS) per square millimeter of sinus mucosa were calculated by using a computer-aided special software under microscope. RESULTS: AR models were successfully established in 9 mice from group A and 8 from group B. Histologic examination of the sinus from group A and B revealed significant mucosal edema and dilated venules. The symptoms were mild in group C, and no symptom was observed in group D. PMN (x +/- s) in group A (139.3 +/- 26.5)/mm2 was significantly higher than that in group B (70.7 +/- 16.7)/mm2, C (63.0 +/- 14.7)/mm2 and D (40.2 +/- 14.1)/mm2 respectively (P < 0.01); EOS and serous IL-5 level in group A (134.6 +/- 25.5)/mm2, (48.2 +/- 13.9) pg/ml and B (116.2 +/- 25.2)/mm2, (40.8 +/- 7.8) pg/ml, were higher than that in group C (16.7 +/- 2.7)/mm2, (23.9 +/- 8.7) pg/ml (P < 0.05) and D (13.4 +/- 4.9)/mm2, (24.6 +/- 6.5) pg/ml (P < 0.05). CONCLUSIONS: The data demonstrate that an ongoing local allergic response augments bacterial infection in mice, and allergic sensitization alone without SP does not induce the sinus infection.