Longitudinal analyses reveal immunological misfiring in severe COVID-19.

Recent studies have provided insights into the pathogenesis of coronavirus disease 2019 (COVID-19)1-4. However, the longitudinal immunological correlates of disease outcome remain unclear. Here we serially analysed immune responses in 113 patients with moderate or severe COVID-19. Immune profiling revealed an overall increase in innate cell lineages, with a concomitant reduction in T cell number. An early elevation in cytokine levels was associated with worse disease outcomes. Following an early increase in cytokines, patients with moderate COVID-19 displayed a progressive reduction in type 1 (antiviral) and type 3 (antifungal) responses. By contrast, patients with severe COVID-19 maintained these elevated responses throughout the course of the disease. Moreover, severe COVID-19 was accompanied by an increase in multiple type 2 (anti-helminths) effectors, including interleukin-5 (IL-5), IL-13, immunoglobulin E and eosinophils. Unsupervised clustering analysis identified four immune signatures, representing growth factors (A), type-2/3 cytokines (B), mixed type-1/2/3 cytokines (C), and chemokines (D) that correlated with three distinct disease trajectories. The immune profiles of patients who recovered from moderate COVID-19 were enriched in tissue reparative growth factor signature A, whereas the profiles of those with who developed severe disease had elevated levels of all four signatures. Thus, we have identified a maladapted immune response profile associated with severe COVID-19 and poor clinical outcome, as well as early immune signatures that correlate with divergent disease trajectories.

Airway remodelling rather than cellular infiltration characterizes both type2 cytokine biomarker-high and -low severe asthma.

BACKGROUND: The most recognizable phenotype of severe asthma comprises people who are blood eosinophil and FeNO-high, driven by type 2 (T2) cytokine biology, which responds to targeted biological therapies. However, in many people with severe asthma, these T2 biomarkers are suppressed but poorly controlled asthma persists. The mechanisms driving asthma in the absence of T2 biology are poorly understood. OBJECTIVES: To explore airway pathology in T2 biomarker-high and -low severe asthma. METHODS: T2 biomarker-high severe asthma (T2-high, n = 17) was compared with biomarker-intermediate (T2-intermediate, n = 21) and biomarker-low (T2-low, n = 20) severe asthma and healthy controls (n = 28). Bronchoscopy samples were processed for immunohistochemistry, and sputum for cytokines, PGD2 and LTE4 measurements. RESULTS: Tissue eosinophil, neutrophil and mast cell counts were similar across severe asthma phenotypes and not increased when compared to healthy controls. In contrast, the remodelling features of airway smooth muscle mass and MUC5AC expression were increased in all asthma groups compared with health, but similar across asthma subgroups. Submucosal glands were increased in T2-intermediate and T2-low asthma. In spite of similar tissue cellular inflammation, sputum IL-4, IL-5 and CCL26 were increased in T2-high versus T2-low asthma, and several further T2-associated cytokines, PGD2 and LTE4 , were increased in T2-high and T2-intermediate asthma compared with healthy controls. CONCLUSIONS: Eosinophilic tissue inflammation within proximal airways is suppressed in T2 biomarker-high and T2-low severe asthma, but inflammatory and structural cell activation is present, with sputum T2-associated cytokines highest in T2 biomarker-high patients. Airway remodelling persists and may be important for residual disease expression beyond eosinophilic exacerbations. Registered at ClincialTrials.gov: NCT02883530.

Cytokines in peritoneal fluid of ovarian neoplasms.

The aim of this study was to evaluate cytokine levels (IL-2, IL-8, TNF-α, IL-5, IL-6 and IL-10) in the peritoneal fluid in non-neoplastic tumours, benign ovarian neoplasms and malignant ovarian neoplasms. Peritoneal fluid or ascites was collected from 117 patients with neoplastic and non-neoplastic ovarian tumours. Cytokine levels were assessed by ELISA. The unpaired groups were compared by the Kruskal-Wallis test with Dunn's post-test. Higher IL-6 levels were found in malignant neoplasms when compared to non-neoplastic tumours (p=.0241). There was no significant difference in the evaluation of other cytokines. Therefore, higher IL-6 levels in peritoneal fluid are related to the diagnosis of ovarian cancer. Further studies should be performed to evaluate the profile of cytokines in the peritoneal fluid of patients with ovarian tumours, and may be a new diagnostic strategy and a future target for treatment.Impact statementWhat is already known on this subject? Cytokines can be dosed in both the serum and peritoneal fluid, and in the ascitic fluid of women with ovarian neoplasia. Elevated levels of IL-6 were found in the ascitic fluid of patients with malignant ovarian tumours.What the results of this study add? To our knowledge, this is the first study in the literature that evaluates a large panel of cytokines in the peritoneal fluid (and not only in ascites), comparing non-neoplastic tumours, benign neoplasms and malignant ovarian neoplasms.What the implications are of these findings for clinical practice and/or further research? The cytokine dosage in the peritoneal fluid should be considered to map a profile of inflammatory cytokines that permeate the peritoneal cavity of patients with ovarian cancer. The dosage of these cytokines can be a potential pre-surgical tumour marker. In addition, a better understanding of the pattern of cytokines around ovarian neoplasia may be targeted for further studies in the development of new therapies for ovarian cancer.

Cytokine clearance with CytoSorb® during cardiac surgery: a pilot randomized controlled trial.

BACKGROUND: Cardiopulmonary bypass (CPB) is often associated with degrees of complex inflammatory response mediated by various cytokines. This response can, in severe cases, lead to systemic hypotension and organ dysfunction. Cytokine removal might therefore improve outcomes of patients undergoing cardiac surgery. CytoSorb® (Cytosorbents, NJ, USA) is a recent device designed to remove cytokine from the blood using haemoadsorption (HA). This trial aims to evaluate the potential of CytoSorb® to decrease peri-operative cytokine levels in cardiac surgery. METHODS: We have conducted a single-centre pilot randomized controlled trial in 30 patients undergoing elective cardiac surgery and deemed at risk of complications. Patients were randomly allocated to either standard of care (n = 15) or CytoSorb® HA (n = 15) during cardiopulmonary bypass (CPB). Our primary outcome was the difference between the two groups in cytokines levels (IL-1a, IL-1b, IL-2, IL-4, IL-5, IL-6, IL-10, TNF-α, IFN-γ, MCP-1) measured at anaesthesia induction, at the end of CPB, as well as 6 and 24 h post-CPB initiation. In a consecutive subgroup of patients (10 in HA group, 11 in control group), we performed cross-adsorber as well as serial measurements of coagulation factors' activity (antithrombin, von Willebrand factor, factor II, V, VIII, IX, XI, and XII). RESULTS: Both groups were similar in terms of baseline and peri-operative characteristics. CytoSorb® HA during CPB was not associated with an increased incidence of adverse event. The procedure did not result in significant coagulation factors' adsorption but only some signs of coagulation activation. However, the intervention was associated neither with a decrease in pro- or anti-inflammatory cytokine levels nor with any improvement in relevant clinical outcomes. CONCLUSIONS: CytoSorb® HA during CPB was not associated with a decrease in pro- or anti-inflammatory cytokines nor with an improvement in relevant clinical outcomes. The procedure was feasible and safe. Further studies should evaluate the efficacy of CytoSorb® HA in other clinical contexts. TRIAL REGISTRATION: ClinicalTrials.gov NCT02775123 . Registered 17 May 2016.

Controversies and opportunities in severe asthma.

PURPOSE OF REVIEW: Despite currently available treatments, many asthma patients remain inadequately controlled, but identifying distinct patient populations (phenotypes/endotypes) may optimize their management. This review discusses some of the controversies and opportunities for improved disease control in severe asthma. RECENT FINDINGS: Currently approved anti-immunoglobulin E and anti-interleukin 5 biologics, which target specific pathways instead of using a 'one size fits all' strategy, are efficacious and well tolerated therapies for severe asthma. The appropriate use of these biologics, and of those in development (e.g., benralizumab and dupilumab), should be aided by further understanding of asthma phenotypes and endotypes, utilizing appropriate biomarkers.Oral corticosteroids are often added as maintenance therapy for patients with severe uncontrolled asthma, but their use is associated with significant adverse effects and should be considered a last option. The true cost of this therapy, including the cost of morbidities associated with its use, remains to be determined.Severe asthma in pediatrics poses a unique opportunity for possible prevention strategies and the potential for primary prevention. Although several avenues for primary prevention are being explored and are out of the scope of this review, we focus our discussion on the use of omalizumab, which has been recently explored in clinical trials. SUMMARY: Appropriate use of biologics in severe asthma should be supported by further understanding of biomarkers predicting response to targeted therapy. Because of their association with significant adverse effects, add-on oral corticosteroids should be considered a last treatment option for patients with uncontrolled severe asthma. Finally, severe asthma in pediatrics poses a unique opportunity for potential prevention strategies.

Programmed cell death-1 expression correlates with disease severity and IL-5 in chronic rhinosinusitis with nasal polyps.

BACKGROUND: Programmed cell death-1 (PD-1) is a negative regulator of T-cell responses. Expression of PD-1 and its ligands PD-L1 and PD-L2 in chronic rhinosinusitis with nasal polyps (CRSwNP) is poorly studied. METHODS: Expression of PD-1, PD-L1, PD-L2, TGF-ß, IL-5, and IL-10 mRNA was measured by real-time quantitative PCR on tissue homogenates of patients with CRSwNP (n = 21) and healthy controls (n = 21) and on primary epithelial cells. Disease severity was scored using the Lund-Mackay scores of maxillofacial computed tomography (CT) scans. Expression of PD-1 and PD-L1/L2 was evaluated at the cellular and tissue levels (n = 6) by flow cytometry and immunohistochemistry. RESULTS: Programmed cell death-1 mRNA expression was increased in tissue homogenates from patients with CRSwNP compared with controls, irrespective of the atopy status. Importantly, expression of PD-1 correlated with the total CT scan scores (r = 0.5, P = 0.02). Additionally, a significant association was found between PD-1 mRNA and expression of IL-5 mRNA in control nasal tissue (r = 0.95, P < 0.0001) and in CRSwNP (r = 0.63, P = 0.002). PD-1 was expressed on different subsets of T cells and CD11b- dendritic cells. Both PD-1 and its ligands were expressed on primary epithelial cells from control nasal tissue and nasal polyp tissue. CONCLUSIONS: Higher PD-1 expression was found in CRSwNP than in nasal tissue from controls. This was associated with disease severity and tissue IL-5 expression but unrelated to the patients' atopy status.

Scanning balanced-path homodyne I/Q-interferometer scheme and its applications.

The balanced-path scheme of a heterodyne interferometer proposed by Yoon et al. has been applied to the scanning homodyne I/Q-interferometer. This provides an 11-dB improvement on common vibration rejection over the heterodyne scheme and, thereby, allows high sensitivity and high stability phase and amplitude measurements for high-speed scanning interferometer applications. It is shown that our new scanning interferometer scheme is very useful for diagnosing a sample that requires complex analysis. As an example, our new scanning interferometer scheme has been applied for obtaining phase and amplitude images of the protein biochip samples prepared by using the sandwich ELISA. The amplitude images are used for diagnosing homogeneity of the sample, while the phase images are used for measuring the phase difference between samples treated with different concentrations of IL-5.

STAT6 controls the number of regulatory T cells in vivo, thereby regulating allergic lung inflammation.

STAT6 plays a central role in IL-4-mediated allergic responses. Several studies indicate that regulatory T cells (Tregs) can be modulated by IL-4 in vitro. We previously showed that STAT6(-/-) mice are highly resistant to allergic lung inflammation even when wild-type Th2 effectors were provided and that they have increased numbers of Tregs. However, the role of STAT6 in modulating Tregs in vivo during allergic lung inflammation has not been thoroughly investigated. To examine Treg and STAT6 interaction during allergic inflammation, STAT6(-/-), STAT6xRAG2(-/-), and RAG2(-/-) mice were subjected to OVA sensitization and challenge following adoptive transfer of OVA-specific, wild-type Th2 effectors with or without prior Treg depletion/inactivation, using anti-CD25 (PC61). As expected, STAT6(-/-) mice were highly resistant to airway inflammation and remodeling. In contrast, allergic lung inflammation was partially restored in STAT6(-/-) mice treated with PC61 to levels observed in STAT6xRAG2(-/-) mice. In some cases, STAT6xRAG2(-/-) mice were also given natural Tregs along with Th2 effectors. Adoptive transfer of natural Tregs caused a substantial reduction in bronchoalveolar lavage eosinophil composition and suppressed airway remodeling and T cell migration into the lung in STAT6xRAG2(-/-) mice to levels comparable to those in STAT6(-/-) mice. These results demonstrate the STAT6-dependent suppression of Tregs in vivo to promote allergic airway inflammation.

Serotype-dependent response of human dendritic cells stimulated with Aggregatibacter actinomycetemcomitans.

AIM: Different serotypes of Aggregatibacter actinomycetemcomitans have been described based on the lipopolysaccharide (LPS)-O-polysaccharide antigenicity. In turn, a distinct effect of A. actinomycetemcomitans serotypes has been described on cell proliferation and pro-inflammatory cytokine production in different human cells. This study was aimed to investigate the differential dendritic cell (DC) response when stimulated with different bacterial strains belonging to the most prevalent serotypes of A. actinomycetemcomitans (a-c). MATERIALS AND METHODS: Dendritic cells were obtained from healthy subjects and stimulated with increasing multiplicity of infection (MOI = 10(-1) -10(2)) of A. actinomycetemcomitans, serotypes a-c, or their lipopolysaccharide (10-50 ng/ml). The levels for interferon (IFN)-γ, tumour necrosis factor (TNF)-α, interleukin (IL)-1ß, IL-5, IL-6, IL-10, IL-12 and IL-23 were quantified by real-time RT-PCR and ELISA. RESULTS: Variable DC responses were detected when stimulated with the different strains of A. actinomycetemcomitans. DCs stimulated with A. actinomycetemcomitans strains belonging to the serotype b or their purified LPS expressed higher levels of IL-1ß, IL-6, IL-12, IL-23, IFN-γ and TNF-α than DCs stimulated with the other serotypes. CONCLUSIONS: Aggregatibacter actinomycetemcomitans strains belonging to the serotype b demonstrated a higher capacity to trigger Th1 and Th17-type cytokine production on DCs. These increased potential is likely explained by a higher immunogenicity of their LPS.

[Effects of suplatast tosilate on airway inflammation and interleukin-5 in asthmatic rats].

OBJECTIVE: To study the effects of suplatast tosilate (IPD) on the airway inflammation and expression of interleukin-5 in asthmatic rats. METHODS: Fifty adult male Sprague-Dawley rats (4-week- old) were randomly assigned to five groups: placebo control, untreated asthma, budesonide(BUD)-treated asthma , early or late IPD intervention group (n=10 rats each). Asthmatic mode was prepared by ovalbumin sensitizion and challenge. Inflammatory cells and the percentage of EOS were detected in bronchoalveolar lavage fluid (BALF). The lung tissues were removed to detect the lung histomorphology. Gene expression of IL-5 was measured by reverse transcription-polymerase chain reaction (RT-PCR). Levels of interleukin 5 (IL-5) in BALF were measured using ELISA. RESULTS: The inflammatory cells and the percentage of EOS in BALF, IL-5 levels in BALF and IL-5 mRNA expression in the lung tissues were obviously higher in the untreated asthma group than the control group (P<0.05), while the parameters in the IPD or BUD-treated asthma groups were significantly lower than the untreated asthma group (P<0.05). CONCLUSIONS: IPD treatment can alleviate airway inflammation in asthmatic rats, possibly through inhibiting IL-5 mRNA transcripts.

The activin A antagonist follistatin inhibits asthmatic airway remodelling.

BACKGROUND: Current pharmacotherapy is highly effective in the clinical management of the majority of patients with stable asthma, however severe asthma remains inadequately treated. Prevention of airway remodelling is a major unmet clinical need in the management of patients with chronic severe asthma and other inflammatory lung diseases. Accumulating evidence convincingly demonstrates that activin A, a member of the transforming growth factor (TGF)-ß superfamily, is a key driver of airway inflammation, but its role in chronic asthmatic airway remodelling is ill-defined. Follistatin, an endogenously produced protein, binds activin A with high affinity and inhibits its bioactivity. The aim of this study was to test the potential of follistatin as a therapeutic agent to inhibit airway remodelling in an experimental model of chronic allergic airway inflammation. METHODS: BALB/c mice were systemically sensitised with ovalbumin (OVA), and challenged with OVA intranasally three times a week for 10 weeks. Follistatin was instilled intranasally during allergen challenge. RESULTS: Chronic allergen challenge induced mucus hypersecretion and subepithelial collagen deposition which persisted after cessation of challenge. Intranasal follistatin (0.05, 0.5, 5 µg) inhibited the airway remodelling and dose-dependently decreased airway activin A and TGF-ß1, and allergen-specific T helper 2 cytokine production in the lung-draining lymph nodes. Follistatin also impaired the loss of TGF-ß1 and activin RIB immunostaining in airway epithelium which occurred following chronic allergen challenge. CONCLUSIONS: These data demonstrate that follistatin attenuates asthmatic airway remodelling. Our findings point to the potential of follistatin as a therapeutic for prevention of airway remodelling in asthma and other inflammatory lung diseases.

The DNA methylation inhibitor 5-azacytidine increases regulatory T cells and alleviates airway inflammation in ovalbumin-sensitized mice.

BACKGROUND: Asthma is characterized as a chronic inflammatory disorder of the airways associated with an enhanced TH2 response to inhaled allergens. CD4+ T regulatory (Treg) cells are controlled by the master transcription factor FoxP3 and strictly maintain peripheral immunotolerance. Epigenetic regulation of FoxP3 by DNA methyltransferase inhibitors, such as 5-azacytidine (Aza), can generate a steady supply of functional Treg cells. Therefore, we propose that Aza can augment Treg cells in vivo to prevent the pathogenesis of asthma. METHODS: BALB/c mice were sensitized with chicken ovalbumin (OVA) and treated with different doses of Aza. Airway hyperresponsiveness to methacholine, eosinophilia in bronchoalveolar lavage fluid, circulating titers of OVA-specific IgG1 and IgE, and stimulating levels of TH2 cytokines from splenocytes were then determined. Cellular populations were examined by flow cytometry. PC61 antibody, which depletes CD25+ cells, was used to verify the role of CD25+ cells in Aza-induced tolerance. RESULTS: Administration of Aza to OVA-sensitized mice diminished airway hyperreactivity, pulmonary eosinophilia, levels of OVA-specific IgG1 and IgE in serum, and secretion of TH2 cytokines from OVA-stimulated splenocytes in a dose-dependent manner. Percentages of CD25+ and FoxP3+ cells in the CD4+ cell population were notably increased in Aza-treated mice compared to sensitized control mice. Furthermore, the major symptoms of asthma were exacerbated by depleting CD25+ cells in Aza-treated mice. CONCLUSIONS: Aza may have applications as a novel clinical strategy to increase the production of Treg cells in order to modulate the airway inflammation associated with asthma.

Reduced immune responses to purified protein derivative and Candida albicans in oral lichen planus.

BACKGROUND: Impairment of cellular immunity is reported in lichen planus, an autoimmune disease affecting mucosae and skin. Our aim was to investigate immune responses directed against a set of microbial antigens in patients with oral lichen planus and in matched controls. METHODS: Venous blood was obtained, and the mononuclear cells were enriched by density gradient centrifugation. The proliferation of peripheral blood mononuclear cells was assessed, following stimulation with purified protein derivative (PPD), Candida albicans, phytohemagglutinin or when cells were left unstimulated, after three or six days of cell culture. The production of interleukin-1ß (IL-1ß), IL-2, IL-4, IL-5, IL-6, IL-10, IL-12, IL-13, IL-17, interferon-γ (IFN-γ), tumour necrosis factor-α (TNF-α), G-CSF, GM-CSF, MCP-1, MIP-ß was assessed in supernatants using the Bio-plex(®) assay and was complemented with ELISA for selected cytokines. RESULTS: Patients with oral lichen planus demonstrated reduced proliferative responses against PPD (P < 0.05) and C. albicans (P < 0.05). The majority of investigated cytokines, including the pro-inflammatory, IFN-γ and TNF-α were expressed at reduced levels in PPD-stimulated supernatants from patients with oral lichen planus. CONCLUSIONS: Collectively, the findings suggested that memory lymphocytes from patients with oral lichen planus (OLP) may have an impaired functional ability to react against certain recall antigens, as part of a generalized response, which may reflect immune regulatory processes. Further studies are needed to clarify the mechanisms of down-regulation in OLP pathogenesis and progression.

The effects of proresolution of ellagic acid in an experimental model of allergic airway inflammation.

Asthma is a disease of airway inflammation characterized by airway hyperresponsiveness, eosinophilic inflammation, and hypersecretion of mucus. Ellagic acid, a compound derived from medicinal plants and fruits, has shown anti-inflammatory activity in several experimental disease models. We used the classical experimental model, in BALB/c mice, of sensibilization with ovalbumin to determine the effect of ellagic acid (10 mg/kg; oral route) in the resolution of allergic airways response. Dexamethasone (1 mg/kg; subcutaneous route) was used as a positive control. The control group consisted of nonimmunized mice that received challenge with ovalbumin. Ellagic acid and dexamethasone or vehicle (water) were administered before or after intranasal allergen challenge. Ellagic acid accelerated the resolution of airways inflammation by decreasing total leukocytes and eosinophils numbers in the bronchoalveolar lavage fluid (BALF), the mucus production and lung inflammation in part by reducing IL-5 concentration, eosinophil peroxidase (EPO) activity, and P-selectin expression, but not activator protein 1 (AP-1) and nuclear factor kappa B (NF-κB) pathways. In addition, ellagic acid enhanced alveolar macrophage phagocytosis of IgG-OVA-coated beads ex vivo, a new proresolving mechanism for the clearance of allergen from the airways. Together, these findings identify ellagic acid as a potential therapeutic agent for accelerating the resolution of allergic airways inflammation.

Experimental model of allergic asthma.

The aim of the study was to prepare and evaluate the experimental model of allergic asthma. Changes in chough reflex, bronchoconstriction and the degree of inflammation were studied in ovalbumin (OVA) sensitized guinea pigs after 0, 7, 14, 21 days of exposure. The cough reflex was induced by citric acid inhalation in conscious animals in a double chamber body plethysmograph. Tracheal smooth muscle reactivity was assessed by examining the in vitro response to histamine (H) (10(-8)-10(-3) mol/l) and in vivo to H nebulization (10(-6) mol/l). BALF levels of IL-4, IL-5 and the eosinophil count were used as parameters of airway inflammation. After 7 days of OVA sensitization, there was an increase in tracheal smooth muscle contractility in vitro to cumulative concentration of H and an increase in cough parameters. After 14 days of OVA sensitization, there was a further increase in tracheal smooth muscle contractility to H, an increase in airway resistance, and a small increase in cough parameters. After 21 day of OVA sensitization, cough parameters were significantly reduced, airway resistance after H inhalation was increased, and there were significant increases in IL-4, IL-5, and eosinophils in BALF. In conclusion, progress in asthmatic inflammation during 21-day OVA sensitization caused a gradual increase in inflammatory mediators, a decline in cough reflex, and enhanced bronchoconstriction. This experimental model of allergic asthma can be used for pharmacological modulations of defense reflexes and inflammation.

Polyphenols and their components in experimental allergic asthma.

The aim of the study was to investigate the potential anti-inflammatory effects in -experimental allergic asthma of natural polyphenolic compounds or their single major components. The experiment was performed after 21-days sensitization of guinea pigs with ovalbumin suspension. Changes in airway reactivity after the long-term treatment with the polyphenolic compounds Provinol and Flavin-7 and their single major components quercetin and resveratrol during were assessed using a whole body plethysmography. Reactivity of tracheal smooth muscle was studied in vitro in response to cumulative doses of the bronchoconstrictive mediators histamine and acetylcholine. Furthermore, concentrations of the inflammatory cytokines IL-4 and IL-5 were measured in bronchoalveolar lavage fluid. The results demonstrate significant anti-inflammatory effects of Provinol and Flavin-7 exerted in the airways. In contrast, chronic treatment with quercetin and resveratrol, single components of the two polyphenols, did not show such activity. We conclude that polyphenolic compounds are more effective in the anti-inflammatory effects in the airways than their separate components.

Adenovirus-mediated delivery of soluble ST2 attenuates ovalbumin-induced allergic asthma in mice.

Allergic asthma is associated with excessive T helper type 2 (Th2) cells activation and airway hyperreactivity (AHR), implicated in the context of significant morbidity and mortality. Soluble ST2, a member of the interleukin (IL)-1 receptor family, has been shown to play a critical role in modulation of inflammatory disorders, yet the function of soluble ST2 in allergic inflammation remains unclear. In this study, we examined the possibility of regulating ovalbumin (OVA)-challenged airway inflammation by recombinant adenovirus-mediated sST2-Fc (Ad-sST2-Fc) gene transfer. Single intranasal administration of Ad-sST2-Fc before allergen challenge in OVA-immunized mice profoundly reduced serum immunoglobulin (Ig)E secretion, eosinophil infiltration and concentrations of IL-4, IL-5 and IL-13 in bronchoalveolar lavage fluid compared with administration of a control Ad vector. Histopathological examination of the lungs revealed that sST2-Fc over-expression markedly suppressed allergen-induced peribronchial inflammation and disruption of the alveolar architecture. Moreover, the beneficial effect of sST2-Fc in allergic lung inflammation is related to blocking the IL-33/ST2L signalling. Taken together, these results suggested that administration of Ad-sST2-Fc gene transfer may have therapeutic potential for the immunomodulatory treatment of OVA-mediated allergic pulmonary diseases.

Increased production of IL-5 and dominant Th2-type response in airways of Churg-Strauss syndrome patients.

OBJECTIVE: Churg-Strauss syndrome (CSS) is a rare systemic vasculitis associated with eosinophilia and asthma. We assessed the local immune response in airways of CSS patients with different activity of the disease. METHODS: Concentration of IL-5, CCL17, CCL22 and CCL26 (ELISA) together with cell expression of T-helper-related genes (real-time PCR array) were measured in bronchoalveolar lavage fluid (BALF) sampled from 11 patients with active CSS, 11 patients with CSS in remission and 9 control subjects with bronchial asthma. RESULTS: In active CSS, both BALF and blood eosinophil counts were increased (P<0.01). BALF cells in active disease were characterized by an increased expression of Th2 and regulatory-type transcripts: STAT6, STAT3, GATA3, IL4, IL5 and IL10 as compared with asthmatics, and STAT5A, CCR4, FOXP3, IL4, IL5 and IL10 when compared with inactive CSS. There was significant increase in BALF concentration of IL-5 and CCL26 in exacerbation of CSS. CCR4-active chemokines were detected more frequently in active disease. We found a strong positive correlation between clinical parameters of disease activity (BVAS, eosinophilia) and expression of IL4, IL5, IL10 and STAT5A. CONCLUSION: These results indicate that as compared with asthma, active-CSS patients have much stronger local Th2 response in the airways. Airway cells may contribute to lung eosinophilia in CSS by producing IL-5 and eosinophil active chemokines.

Combining gene expression microarray- and cluster analysis with sequence-based predictions to identify regulators of IL-13 in allergy.

The Th2 cytokine IL-13 plays a key role in allergy, by regulating IgE, airway hyper secretion, eosinophils and mast cells. In this study, we aimed to identify novel transcription factors (TFs) that potentially regulated IL-13. We analyzed Th2 polarized naïve T cells from four different blood donors with gene expression microarrays to find clusters of genes that were correlated or anti-correlated with IL13. These clusters were further filtered, by selecting genes that were functionally related. In these clusters, we identified three transcription factors (TFs) that were predicted to regulate the expression of IL13, namely CEBPB, E2F6 and AHR. siRNA mediated knockdowns of these TFs in naïve polarized T cells showed significant increases of IL13, following knockdown of CEBPB and E2F6, but not AHR. This suggested an inhibitory role of CEBPB and E2F6 in the regulation of IL13 and allergy. This was supported by analysis of E2F6, but not CEBPB, in allergen-challenged CD4+ T cells from six allergic patients and six healthy controls, which showed decreased expression of E2F6 in patients. In summary, our findings indicate an inhibitory role of E2F6 in the regulation of IL-13 and allergy. The analytical approach may be generally applicable to elucidate the complex regulatory patterns in Th2 cell polarization and allergy.

Macrophage migration inhibitory factor isolated from a parasite inhibited Th2 cytokine production in PBMCs of atopic asthma patients.

BACKGROUND: In a previous study, we demonstrated that the human macrophage migration inhibitory factor (MIF)-like protein (As-MIF) isolated from helminths could inhibit allergic airway inflammation via the recruitment of CD4(+)CD25(+)Foxp3(+) T cells. OBJECTIVE: To evaluate the clinical importance of As-MIF as an antiasthma drug, we evaluated immune responses after recombinant As-MIF (rAs-MIF) treatment in peripheral blood mononuclear cell (PBMC) cultures. METHODS: PBMC was isolated from 10 patients with atopic asthma, 8 patients with nonatopic asthma, and 12 nonatopic healthy subjects, and various concentrations of rAs-MIF were transferred into the PBMC culture medium. After 3 days, we measured the levels of T helper 2 and T helper 1 cytokines via ELISA. RESULTS: In atopic asthma, IL-4 and IL-5 production was significantly reduced in the PBMC cultures after rAs-MIF treatment. These inhibitory effects were not observed in the nonatopic asthma group. By way of contrast, IL-10 production in the PMBC cultures was significantly increased after rAs-MIF treatment in all experimental groups. CONCLUSION: The results of this study are similar to those previously reported in a mouse study, suggesting that As-MIF might be a candidate for the specific treatment of asthma.