Inhaled corticosteroids increase interleukin-10 but reduce macrophage inflammatory protein-1alpha, granulocyte-macrophage colony-stimulating factor, and interferon-gamma release from alveolar macrophages in asthma

Asthma Alleviation by Ginsenoside Rb1 via Promotion of Treg Proliferation and Inflammatory T Cell Inhibition

BACKGROUND

Regulatory T cells (Tregs) are living drugs with feasibility, tolerability, and therapeutic benefits. Although Tregs are linked to asthma prognosis through inflammation regulation, no therapeutic agents specifically designed to manage asthma by upregulating Tregs have been developed to date.

METHODS

We screened a library of 250 natural products using a cytometric bead array. Among the selected candidates, gRb1 was identified for further investigation. The effects of gRb1 on Treg and Th17 populations were evaluated in mouse asthma models and human PBMCs from both healthy donors and asthma patients using flow cytometry and cytokine analysis.

RESULTS

In inflammatory conditions, ginsenoside Rb1 (gRb1, a major ginseng component) increased IL-10- and TGF-β-expressing Treg populations and decreased the Th17 population; activated phospho-STAT5 and NFAT1 in Tregs; inhibited NFAT1 activation in conventional T cells (Tconvs); increased Treg proliferation and Tconv-Treg differentiation, inhibiting Tconv proliferation; and reduced inflammatory cytokine secretion by Tconvs. In asthma model mice, suppression of asthma symptoms by gRb1 was associated with elevated Treg and lower Th17, Th1, and Th2 counts. gRb1 treatment of stimulated PBMCs from patients with asthma and healthy donors increased IL-10- and TGF-β-expressing Treg populations and decreased IL-17A-, IL-22-, IFN-γ-, and TNF-α-expressing T-cell populations.

CONCLUSIONS

gRb1 alleviate asthma by shifting the Treg-inflammatory T cell balance. These findings suggest a strategy for enhancing Treg activity through treatment with gRb1. This may provide a novel therapeutic approach for asthma and related disorders.

Targeting TMEM16A ion channels suppresses airway hyperreactivity, inflammation, and remodeling in an experimental Guinea pig asthma model

Asthma is a chronic inflammatory disease characterized by airway hyperresponsiveness, inflammation, and remodeling. Calcium (Ca2+)-activated chloride (Cl-) channels, such as TMEM16A, are inferred to be involved in asthma. Therefore, the present study investigated the therapeutic potential of TMEM16A inhibition in a guinea pig model of ovalbumin (OVA)-induced allergic asthma. Guinea pigs were treated with a specific blocker, CaCCinh-A01 (10 μM), administered via inhalation. A significant reduction in cough reflex sensitivity and specific airway resistance was observed in animals treated with CaCCinh-A01, highlighting its potential to improve airway function. Despite a reduction in ciliary beating frequency (CBF), CaCCinh-A01 reduced airway mucus viscosity by decreasing the production of mucin-5AC (MUC5AC). The nonspecific reduction in the Th1/Th2 cytokine spectrum following CaCCinh-A01 treatment indicated the suppression of airway inflammation. Additionally, markers associated with airway remodeling were diminished, suggesting that CaCCinh-A01 may counteract structural changes in airway tissues. Therefore, inhibition appears to mitigate the pathological aspects of asthma, including airway hyperresponsiveness, inflammation, and remodeling. However, further studies are required to comprehensively evaluate the potential of TMEM16A as a therapeutic target for asthma.

Genetic polymorphisms in IL-2, IL-10 and FOXP3 are associated with autoimmune neutropenia in early childhood and autoantibody specificity in a Danish cohort

Autoimmune neutropenia (AIN) in early childhood is characterized by chronic neutropenia and positivity for human neutrophil antibodies (HNA), resulting in the excessive destruction of neutrophils. The association between regulatory T cells (Tregs) and AIN has been described, and in this study, we investigated three Treg-associated genes, IL-2, IL-10 and FOXP3. The frequencies of three single nucleotide polymorphisms (SNPs) in IL-2 -330T>G (rs2069762), +114G>T (rs2069763) and IVS3-116 A>G (rs2069772), four SNPs in IL-10 -3575T>A (rs1800890), -1082G>A (rs1800896), -819 C>T (rs1800871) and -592 C>A (rs1800872) and three SNPs in FOXP3 -3499 A>G (rs3761547), -3279 C>A (rs3761548) and -924 A>G (rs2232365) were compared between 166 Danish AIN patients and 358 healthy controls. Disease association was observed for IL-2 IVS3-116 GG (p = 0.0081, OR = 0.35 [0.15-0.80]), IL-10 -3575 TT (p = 0.0078, OR = 1.71 [1.16-2.54]) and IL-10 -1082 AA (p = 0.014, OR = 1.76 [1.14-2.72]) in all patients and FOXP3 -924 (p = 0.0005, A OR = 0.41 [0.25-0.68] and G OR = 2.42 [1.46-4.01]) in male patients. None of the associations were linked to antibody specificity. Disease-associated haplotypes were observed in IL-2 and FOXP3. IL-2 -330T/+114 T/IVS3-116A was associated with anti-FcγRIIIb-positive patients (p = 0.012, OR = 2.07 [1.18-3.62]). FOXP3 -3499A/-3279C/-924A was associated with anti-HNA-1a-positive male patients (p = 0.016, OR = 0.41 [0.20-0.83]), and ACG was associated with female patients, both in the combined group (p = 0.006, OR = NA) and the anti-FcγRIIIb-positive group (p = 0.002, OR = NA). We conclude that our findings reveal a correlation between SNP in Treg-associated genes and AIN, indicating that AIN could be driven by dysfunction of immune homeostatic-evolving Tregs.

The clinical course of hospitalized COVID-19 patients and aggravation risk prediction models: a retrospective, multi-center Korean cohort study

Background

Understanding the clinical course and pivotal time points of COVID-19 aggravation is critical for enhancing patient monitoring. This retrospective, multi-center cohort study aims to identify these significant time points and associate them with potential risk factors, leveraging data from a sizable cohort with mild-to-moderate symptoms upon admission.

Methods

This study included data from 1,696 COVID-19 patients with mild-to-moderate clinical severity upon admission across multiple hospitals in Daegu-Kyungpook Province (Daegu dataset) between February 18 and early March 2020 and 321 COVID-19 patients at Seoul Boramae Hospital (Boramae dataset) collected from February to July 2020. The approach involved: (1) identifying the optimal time point for aggravation using survival analyses with maximally selected rank statistics; (2) investigating the relationship between comorbidities and time to aggravation; and (3) developing prediction models through machine learning techniques. The models were validated internally among patients from the Daegu dataset and externally among patients from the Boramae dataset.

Results

The Daegu dataset showed a mean age of 51.0 ± 19.6 years, with 8 days for aggravation and day 5 being identified as the pivotal point for survival. Contrary to previous findings, specific comorbidities had no notable impact on aggravation patterns. Prediction models utilizing factors including age and chest X-ray infiltration demonstrated promising performance, with the top model achieving an AUC of 0.827 in external validation for 5 days aggravation prediction.

Conclusion

Our study highlights the crucial significance of the initial 5 days period post-admission in managing COVID-19 patients. The identification of this pivotal time frame, combined with our robust predictive models, provides valuable insights for early intervention strategies. This research underscores the potential of proactive monitoring and timely interventions in enhancing patient outcomes, particularly for those at risk of rapid aggravation. Our findings offer a meaningful contribution to understanding the COVID-19 clinical course and supporting healthcare providers in optimizing patient care and resource allocation.

Mesenchymal stem cells overexpressing interleukin-10 prevent allergic airway inflammation

BACKGROUNDS

Allergic airway inflammation is prevalent worldwide and imposes a considerable burden on both society and affected individuals. This study aimed to investigate the therapeutic advantages of mesenchymal stem cells (MSCs) overexpressed interleukin-10 (IL-10) for the treatment of allergic airway inflammation, as both IL-10 and MSCs possess immunosuppressive properties.

METHODS

Induced pluripotent stem cell (iPSC)-derived MSCs were engineered to overexpress IL-10 via lentiviral transfection (designated as IL-10-MSCs). MSCs and IL-10-MSCs were administered intravenously to mice with allergic inflammation induced by ovalbumin (OVA), and the features of allergic inflammation including inflammatory cell infiltration, Th cells in the lungs, and T helper 2 cell (Th2) cytokine levels in bronchoalveolar lavage fluid (BALF) were examined. MSCs and IL-10-MSCs were co-cultured with CD4+ T cells from patients with allergic rhinitis (AR), and the levels of Th2 cells and corresponding type 2 cytokines were studied. RNA-sequence was performed to further investigate the potential effects of MSCs and IL-10-MSCs on CD4+ T cells.

RESULTS

Stable IL-10-MSCs were established and characterised by high IL-10 expression. IL-10-MSCs significantly reduced inflammatory cell infiltration and epithelial goblet cell numbers in the lung tissues of mice with allergic airway inflammation. Inflammatory cell and cytokine levels in BALF also decreased after the administration of IL-10-MSCs. Moreover, IL-10-MSCs showed a stronger capacity to inhibit the levels of Th2 after co-cultured with CD4+ T cells from patients with AR. Furthermore, we elucidated lower levels of IL-5 and IL-13 in IL-10-MSCs treated CD4+ T cells, and blockade of IL-10 significantly reversed the inhibitory effects of IL-10-MSCs. We also reported the mRNA profiles of CD4+ T cells treated with IL-10-MSCs and MSCs, in which IL-10 played an important role.

CONCLUSION

IL-10-MSCs showed positive effects in the treatment of allergic airway inflammation, providing solid support for the use of genetically engineered MSCs as a potential novel therapy for allergic airway inflammation.

Endogenous inhibitory mechanisms in asthma

Endogenous inhibitory mechanisms promote resolution of inflammation, enhance tissue repair and integrity, and promote homeostasis in the lung. These mechanisms include steroid hormones, regulatory T cells, IL-10, prostaglandin E2, prostaglandin I2, lipoxins, resolvins, protectins, maresins, glucagon-like peptide-1 receptor, adrenomedullin, nitric oxide, and carbon monoxide. Here we review the most recent literature regarding these endogenous inhibitory mechanisms in asthma, which remain a promising target for the prevention and treatment of asthma.

Neuroimmune Responses in a New Experimental Animal Model of Cerebral Aspergillosis

Exposure of immunosuppressed individuals to the opportunistic fungal pathogen Aspergillus fumigatus may result in invasive pulmonary aspergillosis (IPA), which can lead to the development of cerebral aspergillosis (CA), a highly lethal infection localized in the central nervous system (CNS). There are no experimental models of CA that effectively mimic human disease, resulting in a considerable knowledge gap regarding mechanisms of neurological pathogenicity and neuroimmune responses during infection. In this report, immunosuppressed mice (via acute, high-dose corticosteroid administration) challenged with A. fumigatus resting conidia intranasally, followed a day later by a 70-fold lower inoculum of pre-swollen conidia intravenously (IN + IV + steroid), demonstrated increased weight loss, signs of severe clinical disease, increased fungal burden in the brain, and significant reduction in survival compared to immunosuppressed mice challenged intranasally only (IN + steroid) or non-immunosuppressed mice challenged both intranasally and intravenously (IN + IV). The IN + IV + steroid group demonstrated significant decreases in monocytes, eosinophils, dendritic cells (DCs), and invasive natural killer T (iNKT) cells, but not neutrophils or γδ T cells, in the brain compared to the IN + IV group. Likewise, the IN + IV + steroid group had significantly lower levels of interleukin (IL)-1β, IL-6, IL-17A, CC motif chemokine ligand 3 (CCL3), CXC chemokine ligand 10 (CXCL10), and vascular endothelial growth factor (VEGF) in the brain compared to the IN + IV group. IN + IV + steroid was superior to both IN + IV + chemotherapy (cytarabine + daunorubicin) and IN + IV + neutropenia for the development of CA. In conclusion, we have developed a well-defined, physiologically relevant model of disseminated CA in corticosteroid-induced immunosuppressed mice with a primary pulmonary infection. This model will serve to advance understanding of disease mechanisms, identify immunopathogenic processes, and help define the protective neuroinflammatory response to CA. IMPORTANCE Invasive fungal infections (IFIs) result in significant mortality in immunosuppressed individuals. Of these, invasive pulmonary aspergillosis (IPA), caused by the opportunistic mold Aspergillus fumigatus, is the most lethal. Lethality in IPA is due to two main factors: destruction of the lung leading to compromised pulmonary function, and dissemination of the organism to extrapulmonary organs. Of these, the CNS is the most common site of dissemination. However, very little is known regarding the pathogenesis of or immune response during cerebral aspergillosis, which is directly due to the lack of an animal model that incorporates immunosuppression, lung infection, and consistent dissemination to the CNS/brain. In this report, we have developed a new experimental animal model of CA which includes the above parameters and characterized the neuroimmune response. We further compared this disseminated CA model to two additional immunosuppressive strategies. Overall, this model of disseminated CA following IPA in an immunosuppressed host provides a novel platform for studying the efficacy of antifungal drugs and immunotherapies for improving disease outcomes.

In utero exposures to mint-flavored JUUL aerosol impair lung development and aggravate house dust mite-induced asthma in adult offspring mice

There are few reports concerning electronic nicotine delivery system (ENDS) use during pregnancy and no studies on asthma in prenatally JUUL-exposed offspring. Here, we tested the hypothesis that in utero JUUL exposure causes unfavorable birth outcomes and lasting pulmonary health effects in adult offspring. BALB/c dams were exposed to either air or mint-flavored JUUL aerosol, 1-hr/d, 20 consecutive days during gestation. Offspring were sacrificed on post-natal day (PND) 0 or at 11-week of age, following house dust mite (HDM) challenge. Gene expression was assessed in the uterine/placental tissue of the dams and lung responses were assessed in offspring at PND0 and at 11 weeks of age. JUUL-exposed offspring exhibited decreased body weights and lengths at PND0. These birth outcomes were accompanied by dysregulation of 54 genes associated with hypoxia and oxidative stress in the uterine/placental tissues of JUUL-exposed dams, as well as 24 genes in the lungs of the offspring related to Wnt signaling, plus 9 genes related to epigenetics, and 7 genes related to inflammation. At 11 weeks of age, JUUL + HDM exposed mice exhibited pulmonary inflammation when compared to their respective air + HDM controls. Additionally, the JUUL + HDM exposure dysregulated several genes associated with allergies and asthma. Further, the JUUL + HDM females showed decreased methylation of the promoter region of the Il10ra gene. Taken together, our mouse model shows that inhalation of JUUL aerosols during pregnancy affects the intrauterine environment, impairs lung development, and heightens the effects of allergic airway responses later in life.

Sex Steroids Effects on Asthma: A Network Perspective of Immune and Airway Cells

A multitude of evidence has suggested the differential incidence, prevalence and severity of asthma between males and females. A compilation of recent literature recognized sex differences as a significant non-modifiable risk factor in asthma pathogenesis. Understanding the cellular and mechanistic basis of sex differences remains complex and the pivotal point of this ever elusive quest, which remains to be clarified in the current scenario. Sex steroids are an integral part of human development and evolution while also playing a critical role in the conditioning of the immune system and thereby influencing the function of peripheral organs. Classical perspectives suggest a pre-defined effect of sex steroids, generalizing estrogens popularly under the “estrogen paradox” due to conflicting reports associating estrogen with a pro- and anti-inflammatory role. On the other hand, androgens are classified as “anti-inflammatory,” serving a protective role in mitigating inflammation. Although considered mainstream and simplistic, this observation remains valid for numerous reasons, as elaborated in the current review. Women appear immune-favored with stronger and more responsive immune elements than men. However, the remarkable female predominance of diverse autoimmune and allergic diseases contradicts this observation suggesting that hormonal differences between the sexes might modulate the normal and dysfunctional regulation of the immune system. This review illustrates the potential relationship between key elements of the immune cell system and their interplay with sex steroids, relevant to structural cells in the pathophysiology of asthma and many other lung diseases. Here, we discuss established and emerging paradigms in the clarification of observed sex differences in asthma in the context of the immune system, which will deepen our understanding of asthma etiopathology.

Corticosteroid resistance in asthma: Cellular and molecular mechanisms

Inhaled glucocorticoids (GCs) are drugs widely used as treatment for asthma patients. They prevent the recruitment and activation of lung immune and inflammatory cells and, moreover, have profound effects on airway structural cells to reverse the effects of disease on airway inflammation. GCs bind to a specific receptor, the glucocorticoid receptor (GR), which is a member of the nuclear receptor superfamily and modulates pro- and anti-inflammatory gene transcription through a number of distinct and complementary mechanisms. Targets genes include many pro-inflammatory mediators such as chemokines, cytokines, growth factors and their receptors. Inhaled GCs are very effective for most asthma patients with little, if any, systemic side effects depending upon the dose. However, some patients show poor asthma control even after the administration of high doses of topical or even systemic GCs. Several mechanisms relating to inflammation have been considered to be responsible for the onset of the relative GC resistance observed in these patients. In these patients, the side-effect profile of GCs prevent continued use of high doses and new drugs are needed. Targeting the defective pathways associated with GC function in these patients may also reactivate GC responsiveness.

Autophagy in asthma and chronic obstructive pulmonary disease

Autophagy (or macroautophagy) is a key cellular process that removes damaged molecules (particularly proteins) and subcellular organelles to maintain cellular homeostasis. There is growing evidence that abnormalities in autophagy may contribute to the pathogenesis of many chronic diseases, including asthma and chronic obstructive pulmonary disease (COPD). In asthma, increased autophagy plays a role in promoting type 2 immune responses and eosinophilic inflammation, whereas decreased autophagy may be important in neutrophilic asthma. Acute exposure to cigarette smoke may activate autophagy, resulting in ciliary dysfunction and death of airway epithelial cells, whereas in stable COPD most studies have demonstrated an impairment in autophagy, with reduced autophagic flux and accumulation of abnormal mitochondria (defective mitophagy) and linked to cellular senescence. Autophagy may be increased or decreased in different cell types and depending on the cellular environment, making it difficult to target autophagy therapeutically. Several existing drugs may activate autophagy, including rapamycin, metformin, carbamazepine, cardiac glycosides and statins, whereas others, such as chloroquine, inhibit this process. However, these drugs are nonspecific and more selective drugs are now in development, which may prove useful as novel agents to treat asthma and COPD in the future.

ICS/LABA Combined With Subcutaneous Immunotherapy Modulates the Th17/Treg Imbalance in Asthmatic Children

Rationale

The imbalance of T helper (Th17) cell and regulatory T (Treg) cell are involved in allergic asthma pathogenesis. We hypothesized that ICS/LABA could modulate the Th17/Treg imbalance and that subcutaneous immunotherapy (SCIT) could coordinate with ICS/LABA to rebalance the dysfunction of Th17/Treg.

Methods

Thirty house dust mites (HDM) allergic asthmatic children and fifteen healthy control subjects were enrolled in this study. Fifteen asthmatic children were treated by ICS/LABA powder inhalation, while the other fifteen asthmatic children were treated by ICS/LABA powder inhalation combined with HDM-SCIT. Asthmatic subjects were followed up for 6 months, but 2 asthmatics treated with ICS/LABA were lost to follow-up. Flow cytometry was used to determine the proportions of Th17 and Treg in CD4⁺ T cells from peripheral blood mononuclear cells (PBMCs). Serum levels of IL-17A and IL-10 were assessed by ELISA.

Result

ICS/LABA treatment significantly reduced the percentage of Th17 cells (1.252 ± 0.134% vs. 2.567 ± 0.386%), serum IL-17A (49.42 ± 2.643 pg/ml vs. 66.75 ± 3.442 pg/ml) and Th17/Treg ratio (0.194 ± 0.025 vs. 0.439 ± 0.072) compared to baseline (P<0.01). The ICS/LABA+HDM-SCIT treatment group showed similar reduction in the percentage of Th17 cells (1.11 ± 0.114% vs. 2.654 ± 0.276%), serum IL-17A (49.23 ± 2.131 pg/ml vs. 66.41 ± 2.616 pg/ml) and the Th17/Treg ratio (0.133 ± 0.015 vs. 0.4193 ± 0.050) (P<0.01). ICS/LABA+HDM-SCIT treatment group demonstrated elevated Treg percentages (8.483 ± 0.408% vs. 6.549 ± 0.299%) and serum IL-10 levels (127.4 ± 4.423 pg/ml vs. 93.15 ± 4.046 pg/ml), resulting in a lower Th17/Treg ratio than the ICS/LABA group.

Conclusion

ICS/LABA treatment regulates Th17/Treg imbalance mainly by mitigating Th17-induced inflammation in asthma patients. The addition of SCIT further enhanced such effect by upregulating Treg cells.

Therapeutic diminution of Interleukin-10 with intranasal theophylline administration in hyposmic patients

OBJECTIVE

To determine changes in nasal mucus Interleukin-10 (IL-10) before and after intranasal theophylline treatment in hyposmic patients, and the relationship of these changes to orally administered theophylline treatment.

DESIGN

IL-10 was measured in nasal mucus samples of 17 normal subjects and 39 patients with hyposmia of multiple etiologies by use of a sensitive spectrophotometric ELISA assay. Hyposmia is defined clinically by standardized evaluation of impaired olfactometry, as well as subjectively self reported by the patient.

RESULTS

Prior to treatment, IL-10 levels in nasal mucus were increased in hyposmic patients compared to controls. Following intranasal theophylline administration, over half of treated patients experienced a decrease of nasal mucus IL-10 toward control levels, correlated with a significant improvement in taste and smell function. Patients who increased with intranasal administration, similar to previously reported oral administration, showed no significant improvement in taste or smell function.

CONCLUSIONS

Nasal mucus IL-10 decreased in patients treated with intranasal theophylline. Mechanisms of action include phosphodiesterase and nuclear factor kappa-B inhibition, correlated with an improvement in both olfaction and gustation. IL-10 is induced by therapeutic and systemic administration of theophylline as with oral dosage, but reduced by lower and localized treatment.

Steroid affected cytokines in aspirin exacerbated respiratory disease

BACKGROUND

Patients with aspirin exacerbated respiratory disease (AERD) are among the most challenging rhinologic patients to treat. AERD has a complex inflammatory milieu of lipid mediators and cytokines. In this study we evaluated cytokine differences in the complex AERD environment at the mucus, epithelial and tissue levels.

METHODS

Samples were acquired at the time of sinus surgery from twenty-one patients (7 steroid-treated, 14 untreated) with aspirin challenge-confirmed AERD. Three methods (sponge adsorption, epithelial brushing, tissue biopsy) were used to acquire samples from the respective sinus sampling sites (mucus, polyp epithelium, and full thickness polyp) of each patient. We measured and compared 16 cytokine concentrations in AERD patients with or without prednisone treatment using the Luminex platform.

RESULTS

In most sampling sites, IL-5, IL-6, IL-10, IL-13, IL-33, CCL20, and TNF-α were detected at higher concentrations than IFN-γ, IL-1β, IL-17A, IL-4, IL-22, IL-17E/IL25 and GM-CSF. Each sampling site had a different pattern of cytokine levels and except for IL-5 and IL-25 there was no correlation among sampling methods for each cytokine tested. The most notable and significant decreases in cytokines from those treated with prednisone were observed in the epithelium for IL-5, IL-10, IL-33, and IFN-γ.

CONCLUSIONS

In the epithelial samples, type 2 associated cytokines IL-5 and IL-33, the anti-inflammatory cytokine IL-10, and IFN-γ were lower in AERD patients treated with prednisone. This work serves as a basis to assess therapeutic-induced mucosal cytokine responses in AERD and indicates that the site of cytokine measurement is an important consideration when assessing results. This article is protected by copyright. All rights reserved.

Cytokine Profiles Before and After Immune Modulation in Hospitalized Patients with COVID-19

We describe the cytokine profiles of a large cohort of hospitalized patients with moderate to critical COVID-19, focusing on IL-6, sIL2R, and IL-10 levels before and after receiving immune modulating therapies, namely, tocilizumab and glucocorticoids. We also discuss the possible roles of sIL2R and IL-10 as markers of ongoing immune dysregulation after IL-6 inhibition. We performed a retrospective chart review of adult patients admitted to a tertiary care center with moderate to critical SARS-CoV-2 infection. Disease severity was based on maximum oxygen requirement during hospital stay to maintain SpO2 > 93% (moderate, 0-3 L NC; severe, 4-6 L NC or non-rebreather; critical, HFNC, NIPPV, or MV). All patients were treated using the institution's treatment algorithm, which included consideration of tocilizumab for severe and critical disease. The most common cytokine elevations among all patients included IL-6, sIL2R, IFN-γ, and IL-10; patients who received tocilizumab had higher incidence of IL-6 and sIL2R elevations. Pre-tocilizumab IL-6 levels increased with disease severity (p = .0151). Both IL-6 and sIL2R levels significantly increased after administration of tocilizumab in all severity groups; IL-10 levels decreased in severe (p = .0203), but not moderate or critical, patients after they received tocilizumab. Cluster analysis revealed association between higher admission IL-6, sIL2R, and CRP levels and disease severity. Mean IL-6, sIL2R, and D-dimer were associated with mortality, and tocilizumab-treated patients with elevated IL-6, IL-10, and D-dimer were more likely to also receive glucocorticoids. Accessible clinical cytokine panels may be useful for monitoring response to treatment in COVID-19. The increase in sIL2R post-tocilizumab, despite administration of glucocorticoids, may indicate the need for combination therapy in order to modulate more than one hyperinflammatory pathway in COVID-19. We also discuss the role of cytokines as potential biomarkers for use of adjunct glucocorticoid therapy.

Glucocorticoid-induced eosinopenia results from CXCR4-dependent bone marrow migration

Glucocorticoids are considered first-line therapy in a variety of eosinophilic disorders. They lead to a transient, profound decrease in circulating human eosinophils within hours of administration. The phenomenon of glucocorticoid-induced eosinopenia has been the basis for the use of glucocorticoids in eosinophilic disorders, and it has intrigued clinicians for 7 decades, yet its mechanism remains unexplained. To investigate, we first studied the response of circulating eosinophils to in vivo glucocorticoid administration in 3 species and found that the response in rhesus macaques, but not in mice, closely resembled that in humans. We then developed an isolation technique to purify rhesus macaque eosinophils from peripheral blood and performed live tracking of zirconium-89-oxine-labeled eosinophils by serial positron emission tomography/computed tomography imaging, before and after administration of glucocorticoids. Glucocorticoids induced rapid bone marrow homing of eosinophils. The kinetics of glucocorticoid-induced eosinopenia and bone marrow migration were consistent with those of the induction of the glucocorticoid-responsive chemokine receptor CXCR4, and selective blockade of CXCR4 reduced or eliminated the early glucocorticoid-induced reduction in blood eosinophils. Our results indicate that glucocorticoid-induced eosinopenia results from CXCR4-dependent migration of eosinophils to the bone marrow. These findings provide insight into the mechanism of action of glucocorticoids in eosinophilic disorders, with implications for the study of glucocorticoid resistance and the development of more targeted therapies. The human study was registered at ClinicalTrials.gov as #NCT02798523.

Bevacizumab regulates inflammatory cytokines and inhibits VEGFR2 signaling pathway in an ovalbumin-induced rat model of airway hypersensitivity

BACKGROUND

Bevacizumab with anti-angiogenesis properties reduces the vascular endothelial growth factor (VEGF) level and has widely been used to treat various diseases such as lung diseases and chronic obstructive pulmonary disease (COPD). This study, therefore, aimed to consider the effects of bevacizumab on VEGF receptor 2 (VEGFR2) and lung inflammation of the ovalbumin-induced rat model of airway hypersensitivity.

MATERIALS AND METHODS

Twenty-one male Wistar rats were randomly divided into 3 groups (n = 7 in each group): (1) control, (2) ovalbumin (OVA)-sensitized, and (3) OVA-sensitized with bevacizumab (OVA + Bmab). Groups 2 and 3 were sensitized with ovalbumin (OVA) and aluminum hydroxide on days 1, 8 and challenged with OVA on day 15 by atomization for 10 days (inhalation). After OVA sensitization, the OVA + Bmab was treated with bevacizumab for 2 weeks. VEGFR2 was semiquantitatively analyzed in the lungs by immunohistochemistry. VEGF was measured in the lung tissue by ELISA method. The mRNA of IL-10 and IL-6 lung tissue were measured by real-time PCR.

RESULTS

Ovalbumin exposure promoted the expression of VEGF and resulted in inflammatory factors overexpression (p ≤ 0.05). However, rats in OVA + Bmab group showed significantly a decrease in VEGFR2 and IL-1β, IL-6, TNFα, and an increase in IL-10 (p ≤ 0.05).

CONCLUSION

The results show that bevacizumab efficiently diminishes bronchial inflammation via reducing the expression of VEGFR2, and IL-6 genes and enhancing the expression of IL-10 gene. Hence, bevacizumab could be considered as a potential candidate drug to control pathological conditions relevant to airway hypersensitivity.

Methylprednisolone Treatment in Brain Death-Induced Lung Inflammation-A Dose Comparative Study in Rats

Background: The process of brain death (BD) leads to a pro-inflammatory state of the donor lung, which deteriorates its quality. In an attempt to preserve lung quality, methylprednisolone is widely recommended in donor lung management. However, clinical treatment doses vary and the dose-effect relation of methylprednisolone on BD-induced lung inflammation remains unknown. The aim of this study was to investigate the effect of three different doses methylprednisolone on the BD-induced inflammatory response.

Methods: BD was induced in rats by inflation of a Fogarty balloon catheter in the epidural space. After 60 min of BD, saline or methylprednisolone (low dose (5 mg/kg), intermediate dose (12.5 mg/kg) or high dose (22.5 mg/kg)) was administered intravenously. The lungs were procured and processed after 4 h of BD. Inflammatory gene expressions were analyzed by RT-qPCR and influx of neutrophils and macrophages were quantified with immunohistochemical staining.

Results: Methylprednisolone treatment reduced neutrophil chemotaxis as demonstrated by lower IL-8-like CINC-1 and E-selectin levels, which was most evident in rats treated with intermediate and high doses methylprednisolone. Macrophage chemotaxis was attenuated in all methylprednisolone treated rats, as corroborated by lower MCP-1 levels compared to saline treated rats. Thereby, all doses methylprednisolone reduced TNF-α, IL-6 and IL-1β tissue levels. In addition, intermediate and high doses methylprednisolone induced a protective anti-inflammatory response, as reflected by upregulated IL-10 expression when compared to saline treated brain-dead rats.

Conclusion: We showed that intermediate and high doses methylprednisolone share most potential to target BD-induced lung inflammation in rats. Considering possible side effects of high doses methylprednisolone, we conclude from this study that an intermediate dose of 12.5 mg/kg methylprednisolone is the optimal treatment dose for BD-induced lung inflammation in rats, which reduces the pro-inflammatory state and additionally promotes a protective, anti-inflammatory response.

Role of Cytokines in EGPA and the Possibility of Treatment with an Anti-IL-5 Antibody

Eosinophilic granulomatosis with polyangiitis (EGPA) is a type of systemic vasculitis with eosinophilia in the peripheral blood, which is preceded by bronchial asthma or allergic disease. EGPA is pathologically characterized by microangiopathy granulomatosis vasculitis. Vasculitis can be exacerbated and cause central nervous system and cardiovascular disorders and gastrointestinal perforation. Histological examination reveals eosinophil infiltration and granulomas in lesions in areas such as the lung, nervous system, and skin. Laboratory tests show inflammatory findings such as C-reactive protein (CRP) elevation, increased eosinophils, elevated serum IgE, and elevated myeloperoxidase-anti-neutrophil cytoplasmic antibodies (MPO-ANCA). MPO-ANCA is positive in approximately 40-70% of cases of this disease. EGPA is a necrotizing vasculitis that affects small- and medium-sized blood vessels; however, it differs from other types of ANCA-related vasculitis (such as microscopic polyangiitis and granulomatosis) because it is preceded by bronchial asthma and eosinophilia in the blood and tissues. Treatment with immunosuppressive agents such as steroids or cyclophosphamide depends on the Five Factor Score, which predicts the prognosis and severity of the condition. If the effect of appropriate treatment with steroids is insufficient, the anti-interleukin-5 antibody mepolizumab can be administered. The combination of mepolizumab with standard treatment leads to a significantly longer duration of remission, a higher proportion of patients who achieve sustained remission, and less steroid use than with a placebo.

COVID-19 and Asthma: Reflection During the Pandemic

Coronavirus disease 2019 (COVID-19) is a global pandemic infectious disease caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), and abnormal, overactivated innate immunity and "cytokine storms" have been proposed as potential pathological mechanisms for rapid COVID-19 progression. Theoretically, asthmatic patients should have increased susceptibility and severity for SARS-CoV-2 infection due to a deficient antiviral immune response and the tendency for exacerbation elicited by common respiratory viruses. However, existing studies have not shown an expected prevalence of asthmatic individuals among COVID-19 patients. Certain aspects of type 2 immune response, including type 2 cytokines (IL-4, IL-13, etc.) and accumulation of eosinophils, might provide potential protective effects against COVID-19. Furthermore, conventional therapeutics for asthma, including inhaled corticosteroids, allergen immunotherapy (AIT), and anti-IgE monoclonal antibody, might also reduce the risks of asthmatics suffering infection of the virus through alleviating inflammation or enhancing antiviral defense. The interactions between COVID-19 and asthma deserve further attention and clarification.

Glucocorticoids-All-Rounders Tackling the Versatile Players of the Immune System

Glucocorticoids regulate fundamental processes of the human body and control cellular functions such as cell metabolism, growth, differentiation, and apoptosis. Moreover, endogenous glucocorticoids link the endocrine and immune system and ensure the correct function of inflammatory events during tissue repair, regeneration, and pathogen elimination via genomic and rapid non-genomic pathways. Due to their strong immunosuppressive, anti-inflammatory and anti-allergic effects on immune cells, tissues and organs, glucocorticoids significantly improve the quality of life of many patients suffering from diseases caused by a dysregulated immune system. Despite the multitude and seriousness of glucocorticoid-related adverse events including diabetes mellitus, osteoporosis and infections, these agents remain indispensable, representing the most powerful, and cost-effective drugs in the treatment of a wide range of rheumatic diseases. These include rheumatoid arthritis, vasculitis, and connective tissue diseases, as well as many other pathological conditions of the immune system. Depending on the therapeutically affected cell type, glucocorticoid actions strongly vary among different diseases. While immune responses always represent complex reactions involving different cells and cellular processes, specific immune cell populations with key responsibilities driving the pathological mechanisms can be identified for certain autoimmune diseases. In this review, we will focus on the mechanisms of action of glucocorticoids on various leukocyte populations, exemplarily portraying different autoimmune diseases as heterogeneous targets of glucocorticoid actions: (i) Abnormalities in the innate immune response play a crucial role in the initiation and perpetuation of giant cell arteritis (GCA). (ii) Specific types of CD4+ T helper (Th) lymphocytes, namely Th1 and Th17 cells, represent important players in the establishment and course of rheumatoid arthritis (RA), whereas (iii) B cells have emerged as central players in systemic lupus erythematosus (SLE). (iv) Allergic reactions are mainly triggered by several different cytokines released by activated Th2 lymphocytes. Using these examples, we aim to illustrate the versatile modulating effects of glucocorticoids on the immune system. In contrast, in the treatment of lymphoproliferative disorders the pro-apoptotic action of glucocorticoids prevails, but their mechanisms differ depending on the type of cancer. Therefore, we will also give a brief insight into the current knowledge of the mode of glucocorticoid action in oncological treatment focusing on leukemia.

Activation of Resolution Pathways to Prevent and Fight Chronic Inflammation: Lessons From Asthma and Inflammatory Bowel Disease

Formerly considered as a passive process, the resolution of acute inflammation is now recognized as an active host response, with a cascade of coordinated cellular and molecular events that promotes termination of the inflammatory response and initiates tissue repair and healing. In a state of immune fitness, the resolution of inflammation is contained in time and space enabling the restoration of tissue homeostasis. There is increasing evidence that poor and/or inappropriate resolution of inflammation participates in the pathogenesis of chronic inflammatory diseases, extending in time the actions of pro-inflammatory mechanisms, and responsible in the long run for excessive tissue damage and pathology. In this review, we will focus on how resolution can be the target for therapy in "Th1/Th17 cell-driven" immune diseases and "Th2 cell-driven" immune diseases, with inflammatory bowel diseases (IBD) and asthma, as relevant examples. We describe the main cells and mediators stimulating the resolution of inflammation and discuss how pharmacological and dietary interventions but also life style factors, physical and psychological conditions, might influence the resolution phase. A better understanding of the impact of endogenous and exogenous factors on the resolution of inflammation might open a whole area in the development of personalized therapies in non-resolving chronic inflammatory diseases.

High-Dose IL-2 Skews a Glucocorticoid-Driven IL-17+IL-10+ Memory CD4+ T Cell Response towards a Single IL-10-Producing Phenotype

Glucocorticoids are known to increase production of the anti-inflammatory cytokine IL-10, and this action is associated with their clinical efficacy in asthmatics. However, glucocorticoids also enhance the synthesis of IL-17A by PBMCs, which, in excess, is associated with increased asthma severity and glucocorticoid-refractory disease. In this study, we show that the glucocorticoid dexamethasone significantly increased IL-10 production by human memory CD4+ T cells from healthy donors, as assessed by intracellular cytokine staining. In addition, dexamethasone increased production of IL-17A, IL-17F, and IL-22, with the most striking enhancement in cells coproducing Th17-associated cytokines together with IL-10. Of note, an increase in IFN-γ+IL-10+ cells was also observed despite overall downregulation of IFN-γ production. These dexamethasone-driven IL-10+ cells, and predominantly the IL-17+IL-10+ double-producing cells, were markedly refractory to the inhibitory effect of dexamethasone on proliferation and IL-2Rα expression, which facilitated their preferential IL-2-dependent expansion. Although lower concentrations of exogenous IL-2 promoted IL-10+ cells coproducing proinflammatory cytokines, higher IL-2 doses, both alone and in combination with dexamethasone, increased the proportion of single IL-10+ T cells. Thus, glucocorticoid-induced IL-10 is only accompanied by an increase of IL-17 in a low IL-2 setting, which is, nevertheless, likely to be protective owing to the induction of regulatory IL-17+IL-10+-coproducing cells. These findings open new avenues of investigation with respect to the role of IL-2 in glucocorticoid responsiveness that have potential implications for optimizing the benefit/risk ratio of glucocorticoids in the clinic.

Regulatory T cells and asthma

Asthma is a chronic disease of airway inflammation due to excessive T helper cell type 2 (Th2) response. Present treatment based on inhalation of synthetic glucocorticoids can only control Th2-driven chronic eosinophilic inflammation, but cannot change the immune tolerance of the body to external allergens. Regulatory T cells (Tregs) are the main negative regulatory cells of the immune response. Tregs play a great role in regulating allergic, autoimmune, graft-versus-host responses, and other immune responses. In this review, we will discuss the classification and biological characteristics, the established immunomodulatory mechanisms, and the characteristics of induced differentiation of Tregs. We will also discuss the progress of Tregs in the field of asthma. We believe that further studies on the regulatory mechanisms of Tregs will provide better treatments and control strategies for asthma.

Regulatory cytokine function in the respiratory tract

The respiratory tract is an important site of immune regulation; required to allow protective immunity against pathogens, while minimizing tissue damage and avoiding aberrant inflammatory responses to inhaled allergens. Several cell types work in concert to control pulmonary immune responses and maintain tolerance in the respiratory tract, including regulatory and effector T cells, airway and interstitial macrophages, dendritic cells and the airway epithelium. The cytokines transforming growth factor β, interleukin (IL-) 10, IL-27, and IL-35 are key coordinators of immune regulation in tissues such as the lung. Here, we discuss the role of these cytokines during respiratory infection and allergic airway disease, highlighting the critical importance of cellular source and immunological context for the effects of these cytokines in vivo.

Association of Elevated Serum GM-CSF, IFN-γ, IL-4, and TNF-α Concentration with Tobacco Smoke Induced Chronic Obstructive Pulmonary Disease in a South Indian Population

Background

Chronic obstructive pulmonary disease (COPD) is a devastating condition with limited pharmacotherapeutic options and exceptionally high public-health burden globally as well as in India. Tobacco smoking is the primary cause for COPD among men in India. Systemic inflammation involving altered regulation of cytokines controlling the host defense mechanism is a hallmark of COPD pathogenesis. However, biomarker discovery studies are limited among Indian COPD patients.

Methods

We assessed the serum concentrations [median (25th-75th percentile) pg/ml] of interleukin (IL)-2,4,6,8,10, granulocyte macrophage colony stimulating factor (GM-CSF), interferon gamma (IFN-γ), and tumor necrosis factor alpha (TNF-α) using a multiplexed immunoassay. Our study cohort consisted of 30 tobacco smokers with COPD (TS COPD) and 20 tobacco smokers without COPD (TS CONTROL) from South India. The study population was matched for age, sex (male), and tobacco consumption (pack-years). COPD was diagnosed according to the global initiative for chronic obstructive lung disease (GOLD) criteria of persistent airflow obstruction determined by the ratio of postbronchodilator forced expiratory volume in 1 second/forced vital capacity (FEV₁/FVC) of <0.7. A validated structured questionnaire-based survey [Burden of Obstructive Lung Disease (BOLD) study] and spirometry were performed during house to house visit of the field study. Statistical analysis included nonparametric (two-tailed) Mann-Whitney U and Spearman rank test, as appropriate (significance: p<0.05).

Results

Serum GM-CSF [69.64 (46.67, 97.48); 36.78 (30.07, 53.88), p=0.014], IFN-γ [51.06 (17.00, 84.86); 11.70 (3.18, 32.81), p=0.017], IL-4 [9.09 (1.8, 19.9); 1.8 (1.8, 4.46); p=0.024], and TNF-α [20.68 (5.5, 29.26); 3.5 (3.5, 4.5); p<0.001] concentrations (pg/ml) were increased in TS COPD subjects compared to TS CONTROL. A weak correlation between lung function parameters and cytokine concentrations was detected.

Conclusion

Our pilot study reveals GM-CSF, IFN-γ, IL-4, and TNF-α as plausible COPD susceptibility biomarkers within the investigated South Indian population that needs to be validated in a larger cohort.

Increased Susceptibility to Allergic Asthma with the Impairment of Respiratory Tolerance Caused by Psychological Stress

BACKGROUND

Bronchial asthma is characterized by type 2 T helper (Th2) cell inflammation, essentially due to a breakdown of immune tolerance to harmless environmental allergens. Etiologically, experiences of psychological stress can be associated with a heightened prevalence of asthma. However, the mechanisms underlying stress-related asthma development are unclear. In this study, we examined whether psychological stress increases susceptibility to allergic asthma by downregulating immune tolerance.

METHODS

Female BALB/c mice were sensitized with ovalbumin/alum, followed by ovalbumin inhalation. Ovalbumin inhalation induced immune tolerance before sensitization occurred. Some mice were exposed to restraint stress during tolerance induction or sensitization. Asthma development was evaluated by airway responsiveness, inflammation, cytokine expression, and IgE synthesis. Sensitization was evaluated by measuring proliferation and cytokine production by splenocytes. The effects of stress exposure on the numbers and functions of dendritic cells and regulatory T (Treg) cells in bronchial lymph nodes and spleens were evaluated. To investigate the role of endogenous glucocorticoid in inhibiting immune tolerance after stress exposure, we examined the effects of (i) a glucocorticoid-receptor antagonist administered prior to stress exposure, and (ii) exogenous gluco-corticoid (instead of stress exposure).

RESULTS

Asthmatic responses and Th2-biased sensitization, which were suppressed in tolerized mice, re-emerged in tolerized mice stressed during tolerance induction in association with decreased tolerogenic dendritic and Treg cell numbers. The effects of stress exposure on tolerized mice were abolished by administering a glucocorticoid-receptor antagonist and reproduced by administering exogenous glucocorticoid without stress.

CONCLUSIONS

Our findings suggested that psychological stress can potentially increase allergic asthma susceptibility by inhibiting immune tolerance.

Estrogen Signaling Contributes to Sex Differences in Macrophage Polarization during Asthma

Allergic asthma is a chronic Th2 inflammation in the lungs that constricts the airways and presents as coughing and wheezing. Asthma mostly affects boys in childhood and women in adulthood, suggesting that shifts in sex hormones alter the course of the disease. Alveolar macrophages have emerged as major mediators of allergic lung inflammation in animal models as well as humans. Whether sex differences exist in macrophage polarization and the molecular mechanism(s) that drive differential responses are not well understood. We found that IL-4-stimulated bone marrow-derived and alveolar macrophages from female mice exhibited greater expression of M2 genes in vitro and after allergen challenge in vivo. Alveolar macrophages from female mice exhibited greater expression of the IL-4Rα and estrogen receptor (ER) α compared with macrophages from male mice following allergen challenge. An ERα-specific agonist enhanced IL-4-induced M2 gene expression in macrophages from both sexes, but more so in macrophages from female mice. Furthermore, IL-4-stimulated macrophages from female mice exhibited more transcriptionally active histone modifications at M2 gene promoters than did macrophages from male mice. We found that supplementation of estrogen into ovariectomized female mice enhanced M2 polarization in vivo upon challenge with allergen and that macrophage-specific deletion of ERα impaired this M2 polarization. The effects of estrogen are long-lasting; bone marrow-derived macrophages from ovariectomized mice implanted with estrogen exhibited enhanced IL-4-induced M2 gene expression compared with macrophages from placebo-implanted littermates. Taken together, our findings suggest that estrogen enhances IL-4-induced M2 gene expression and thereby contributes to sex differences observed in asthma.

Spectrum of T-lymphocyte activities regulating allergic lung inflammation

Despite advances in the treatment of asthma, optimization of symptom control remains an unmet need in many patients. These patients, labeled severe asthma, are responsible for a substantial fraction of the disease burden. In these patients, research is needed to define the cellular and molecular pathways contributing to disease which in large part are refractory to corticosteroid treatment. The causes of steroid-resistant asthma are multifactorial and result from complex interactions of genetics, environmental factors, and innate and adaptive immunity. Adaptive immunity, addressed here, integrates the activities of distinct T-cell subsets and by definition is dynamic and responsive to an ever-changing environment and the influences of epigenetic modifications. These T-cell subsets exhibit different susceptibilities to the actions of corticosteroids and, in some, corticosteroids enhance their functional activation. Moreover, these subsets are not fixed in lineage differentiation but can undergo transcriptional reprogramming in a bidirectional manner between protective and pathogenic effector states. Together, these factors contribute to asthma heterogeneity between patients but also in the same patient at different stages of their disease. Only by carefully defining mechanistic pathways, delineating their sensitivity to corticosteroids, and determining the balance between regulatory and effector pathways will precision medicine become a reality with selective and effective application of targeted therapies.

Theophylline Represses IL-8 Secretion from Airway Smooth Muscle Cells Independently of Phosphodiesterase Inhibition. Novel Role as a Protein Phosphatase 2A Activator

Theophylline is an old drug experiencing a renaissance owing to its beneficial antiinflammatory effects in chronic respiratory diseases, such as asthma and chronic obstructive pulmonary disease. Multiple modes of antiinflammatory action have been reported, including inhibition of the enzymes that degrade cAMP-phosphodiesterase (PDE). Using primary cultures of airway smooth muscle (ASM) cells, we recently revealed that PDE4 inhibitors can potentiate the antiinflammatory action of β2-agonists by augmenting cAMP-dependent expression of the phosphatase that deactivates mitogen-activated protein kinase (MAPK)-MAPK phosphatase (MKP)-1. Therefore, the aim of this study was to address whether theophylline repressed cytokine production in a similar, PDE-dependent, MKP-1-mediated manner. Notably, theophylline did not potentiate cAMP release from ASM cells treated with the long-acting β2-agonist formoterol. Moreover, theophylline (0.1-10 μM) did not increase formoterol-induced MKP-1 messenger RNA expression nor protein up-regulation, consistent with the lack of cAMP generation. However, theophylline (at 10 μM) was antiinflammatory and repressed secretion of the neutrophil chemoattractant cytokine IL-8, which is produced in response to TNF-α. Because theophylline's effects were independent of PDE4 inhibition or antiinflammatory MKP-1, we then wished to elucidate the novel mechanisms responsible. We investigated the impact of theophylline on protein phosphatase (PP) 2A, a master controller of multiple inflammatory signaling pathways, and show that theophylline increases TNF-α-induced PP2A activity in ASM cells. Confirmatory results were obtained in A549 lung epithelial cells. PP2A activators have beneficial effects in ex vivo and in vivo models of respiratory disease. Thus, our study is the first to link theophylline with PP2A activation as a novel mechanism to control respiratory inflammation.

A Novel TBX19 Gene Mutation in a Case of Congenital Isolated Adrenocorticotropic Hormone Deficiency Presenting with Recurrent Respiratory Tract Infections

INTRODUCTION

Congenital isolated adrenocorticotropic hormone deficiency (CIAD) is a rare disease characterized by low adrenocorticotropic hormone (ACTH) and cortisol levels. To date, recurrent pulmonary infections in infancy have not been reported as an accompanying symptom of CIAD.

CASE PRESENTATION

A 7-year-old boy was hospitalized nine times for recurrent lower respiratory tract infections. The results of all tests for the possible causes of wheezing were within the normal limits. His ACTH and cortisol levels were persistently low. All other pituitary hormone levels, and adrenal ultrasound and pituitary magnetic resonance imaging results, were normal. Molecular analyses confirmed the diagnosis of CIAD by identifying compound heterozygosity for two mutations in the TBX19 gene. The first was a novel frameshift c.665delG variant in exon 4 of the TBX19 gene, leading to premature termination that was predicted to result in a non-functional truncated protein. The second was a nonsense C-to-T transition in exon 6 of the TBX19 gene, resulting in an arg286-to-ter mutation (dbSNP: rs74315376). Both parents were heterozygous for one of the mutations.

CONCLUSION

Here, we presented a new mutation in the TBX19 gene in a patient with CIAD who presented with recurrent respiratory tract infections. This expands the mutation spectrum in this disorder. To conclude, adrenal insufficiency should be considered in patients with unexplained recurrent infections to prevent a delay in diagnosis.

Mechanisms Mediating Pediatric Severe Asthma and Potential Novel Therapies

Although a rare disease, severe therapy-resistant asthma in children is a cause of significant morbidity and results in utilization of approximately 50% of health-care resources for asthma. Improving control for children with severe asthma is, therefore, an urgent unmet clinical need. As a group, children with severe asthma have severe and multiple allergies, steroid resistant airway eosinophilia, and significant structural changes of the airway wall (airway remodeling). Omalizumab is currently the only add-on therapy that is licensed for use in children with severe asthma. However, limitations of its use include ineligibility for approximately one-third of patients because of serum IgE levels outside the recommended range and lack of clinical efficacy in a further one-third. Pediatric severe asthma is thus markedly heterogeneous, but our current understanding of the different mechanisms underpinning various phenotypes is very limited. We know that there are distinctions between the factors that drive pediatric and adult disease since pediatric disease develops in the context of a maturing immune system and during lung growth and development. This review summarizes the current data that give insight into the pathophysiology of pediatric severe asthma and will highlight potential targets for novel therapies. It is apparent that in order to identify novel treatments for pediatric severe asthma, the challenge of undertaking mechanistic studies using age appropriate experimental models and airway samples from children needs to be accepted to allow a targeted approach of personalized medicine to be achieved.

CD4+ Th2 cells are directly regulated by IL-10 during allergic airway inflammation

Interleukin-10 (IL-10) is an important regulatory cytokine required to control allergy and asthma. IL-10-mediated regulation of T cell-mediated responses was previously thought to occur indirectly via antigen-presenting cells. However, IL-10 can act directly on regulatory T cells and T helper type 17 (Th17) cells. In the context of allergy, it is therefore unclear whether IL-10 can directly regulate T helper type 2 (Th2) cells and whether this is an important regulatory axis during allergic responses. We sought to determine whether IL-10 signaling in CD4⁺ Th2 cells was an important mechanism of immune regulation during airway allergy. We demonstrate that IL-10 directly limits Th2 cell differentiation and survival in vitro and in vivo. Ablation of IL-10 signaling in Th2 cells led to enhanced Th2 cell survival and exacerbated pulmonary inflammation in a murine model of house dust mite allergy. Mechanistically, IL-10R signaling regulated the expression of several genes in Th2 cells, including granzyme B. Indeed, IL-10 increased granzyme B expression in Th2 cells and led to increased Th2 cell death, identifying an IL-10-regulated granzyme B axis in Th2 cells controlling Th2 cell survival. This study provides clear evidence that IL-10 exerts direct effects on Th2 cells, regulating the survival of Th2 cells and severity of Th2-mediated allergic airway inflammation.

The Potential Role of 8-Oxoguanine DNA Glycosylase-Driven DNA Base Excision Repair in Exercise-Induced Asthma

Asthma is characterized by reversible airway narrowing, shortness of breath, wheezing, coughing, and other symptoms driven by chronic inflammatory processes, commonly triggered by allergens. In 90% of asthmatics, most of these symptoms can also be triggered by intense physical activities and severely exacerbated by environmental factors. This condition is known as exercise-induced asthma (EIA). Current theories explaining EIA pathogenesis involve osmotic and/or thermal alterations in the airways caused by changes in respiratory airflow during exercise. These changes, along with existing airway inflammatory conditions, are associated with increased cellular levels of reactive oxygen species (ROS) affecting important biomolecules including DNA, although the underlying molecular mechanisms have not been completely elucidated. One of the most abundant oxidative DNA lesions is 8-oxoguanine (8-oxoG), which is repaired by 8-oxoguanine DNA glycosylase 1 (OGG1) during the base excision repair (BER) pathway. Whole-genome expression analyses suggest a cellular response to OGG1-BER, involving genes that may have a role in the pathophysiology of EIA leading to mast cell degranulation, airway hyperresponsiveness, and bronchoconstriction. Accordingly, this review discusses a potential new hypothesis in which OGG1-BER-induced gene expression is associated with EIA symptoms.

Intratracheal therapy with autologous bone marrow-derived mononuclear cells reduces airway inflammation in horses with recurrent airway obstruction

This research evaluated the effects of bone marrow-derived mononuclear cells (BMMCs) on the inflammatory process in the equine recurrent airway obstruction (RAO). Eight horses in RAO clinical score were divided into cell therapy group (Gcel) treated with a single intratracheal dose of BMMCs, and dexamethasone group (Gdex) treated with 21days of oral dexamethasone. The horses were clinically revaluated on days 7 and 21, together with cytological evaluation of the BALF, and detection of inflammatory markers (interleukins [IL]-10, -4, and -17, and interferon γ and α). There were decreases in respiratory effort and clinical score on days 7 and 21(p<0.05) for both groups. The percentage of neutrophils decreased and macrophages increased on days 7 and 21 (p<0.005) in both groups. IL-10 levels increased in the Gcel group on day 21 compared to days 0 and 7 (p<0.05), but this was not observed in the Gdex group. The quantification of IL-4, IL-17, IFN-γ, and IFN-α did not change between evaluations in both groups. These preliminary results suggest that BMMCs may ameliorate the inflammatory response of RAO.

Omalizumab (anti-IgE) therapy in the asthma-COPD overlap syndrome (ACOS) and its effects on circulating cytokine levels

CONTEXT

The term "asthma-chronic obstructive pulmonary disease (COPD) overlap syndrome" (ACOS) has been applied to the condition, in which a person has clinical features of both asthma and COPD.

METHODS

The patients (N = 10) were presented to our clinic with low lung function, limited reversibility of airway obstruction, hyperinflation, abnormal body composition, dyspnea and episodic wheezing. Based on the clinical and laboratory findings, the patients were diagnosed with ACOS. Patients' serum IL-2 (sIL-2), sIL-4 sIL-6, sIL-10, sIL-17, sTNF-α and sIFN-γ levels were investigated as an apoptotic marker and a marker for inflammation.

RESULTS

Having undergone omalizumab treatment and a long-term (12 months) later, patients had a decreased IgE, fractional exhaled nitric oxide concentrations (FENO), eosinophil, neutrophils, macrophages, eosinophil cationic peptide (ECP) and sIL-4 levels.

CONCLUSION

To our knowledge, this is the first documentation of omalizumab use in ACOS. We demonstrated decreased IL-4, allergic pulmonary symptoms (dyspnea, wheezing, bronchial hyper responsiveness) and migraine attacks in the patients.

Budesonide inhalation ameliorates endotoxin-induced lung injury in rabbits

Acute respiratory distress syndrome (ARDS) is a serious clinical problem that has a 30-50% mortality rate. Budesonide has been used to reduce lung injury. This study aims to investigate the effects of nebulized budesonide on endotoxin-induced ARDS in a rabbit model. Twenty-four rabbits were randomized into three groups. Rabbits in the control and budesonide groups were injected with endotoxin. Thereafter, budesonide or saline was instilled, ventilated for four hours, and recovered spontaneous respiratory. Peak pressure, compliance, and PaO2/FiO2 were monitored for 4 h. After seven days, PaO2/FiO2 ratios were measured. Wet-to-dry weight ratios, total protein, neutrophil elastase, white blood cells, and percentage of neutrophils in BALF were evaluated. TNF-α, IL-1β, IL-8, and IL-10 in BALF were detected. Lung histopathologic injury and seven-day survival rate of the three groups were recorded. Peak pressure was downregulated, but compliance and PaO2/FiO2 were upregulated by budesonide. PaO2/FiO2 ratios significantly increased due to budesonide. Wet-to-dry weight ratios, total protein, neutrophil elastase, white blood cells and percentage of neutrophils in BALF decreased in the budesonide group. TNF-α, IL-1β, and IL-8 levels decreased in BALF, while IL-10 levels increased in the budesonide group. Lung injuries were reduced and survival rate was upregulated by budesonide. Budesonide effectively ameliorated respiratory function, attenuated endotoxin-induced lung injury, and improved the seven-day survival rate.

The PPAR-γ antagonist GW9662 elicits differentiation of M2c-like cells and upregulation of the MerTK/Gas6 axis: a key role for PPAR-γ in human macrophage polarization

Background

The nuclear receptors PPAR-γ and LXRs regulate macrophage lipid metabolism and macrophage mediated inflammation. We examined the influence of these molecules on macrophage alternative activation, with particular focus on differentiation of “M2c” anti-inflammatory cells.

Methods

We cultured human monocytes in M0, M1, M2a or M2c macrophage differentiating conditions, in the presence or absence of PPAR-γ and LXR ligands. Flow cytometry was used to analyze membrane expression of phenotypic markers. Basal and LPS-stimulated production of soluble mediators was measured by ELISA. Efferocytosis assays were performed by coincubating monocytes/macrophages with apoptotic neutrophils.

Results

We found that PPAR-γ inhibition, using the PPAR-γ antagonist GW9662, elicits differentiation of M2c-like (CD206⁺ CD163⁺ CD16⁺) cells and upregulation of the MerTK/Gas6 axis. Exposure of differentiating macrophages to IFN-γ, GM-CSF or LPS (M1 conditions), however, hampers GW9662 induction of MerTK and Gas6. When macrophages are differentiated with IL-4 (M2a conditions), addition of GW9662 results into an M2a (CD206⁺ CD209⁺ CD163⁻ MerTK⁻) to M2c (CD206^high CD209⁻ CD163⁺ MerTK⁺) polarization shift. Conversely, in the presence of dexamethasone (M2c conditions), the PPAR-γ agonist rosiglitazone attenuates CD163 and MerTK upregulation. The LXR agonist T0901317 induces MerTK independently of M2c polarization; indeed, CD206, CD163 and CD16 are downregulated. GW9662-differentiated M2c-like cells secrete high levels of Gas6 and low amounts of TNF-α and IL-10, mimicking dexamethasone effects in vitro. However, unlike conventional M2c cells, GW9662-differentiated cells do not show enhanced efferocytic ability.

Conclusions

Our results provide new insights into the role of PPAR-γ and LXR receptors in human macrophage activation and reveal the existence of different patterns regulating MerTK expression. Unexpectedly, PPAR-γ appears to negatively control the expansion of a discrete subset of M2c-like anti-inflammatory macrophages.

Long-Term Exposure to House Dust Mite Leads to the Suppression of Allergic Airway Disease Despite Persistent Lung Inflammation

BACKGROUND

Allergic asthma is a major cause of worldwide morbidity and results from inadequate immune regulation in response to innocuous, environmental antigens. The need exists to understand the mechanisms that promote nonreactivity to human-relevant allergens such as house dust mite (HDM) in order to develop curative therapies for asthma. The aim of our study was to compare the effects of short-, intermediate- and long-term HDM administration in a murine asthma model and determine the ability of long-term HDM exposure to suppress allergic inflammation.

METHODS

C57BL/6 mice were intranasally instilled with HDM for short-term (2 weeks), intermediate-term (5 weeks) and long-term (11 weeks) periods to induce allergic airway disease (AAD). The severity of AAD was compared across all stages of the model via both immunological and pulmonary parameters.

RESULTS

Short- and intermediate-term HDM exposure stimulated the development of AAD that included eosinophilia in the bronchoalveolar lavage fluid (BALF), pronounced airway hyperreactivity (AHR) and evidence of lung inflammation. Long-term HDM exposure promoted the suppression of AAD, with a loss of BALF eosinophilia and AHR despite persistent mononuclear inflammation in the lungs. Suppression of AAD with long-term HDM exposure was associated with an increase in both Foxp3+ regulatory T cells and IL-10-positive alveolar macrophages at the site of inflammation.

CONCLUSIONS

This model recapitulates the key features of human asthma and may facilitate investigation into the mechanisms that promote immunological tolerance against clinically relevant aeroallergens.

Vitamin D as an adjunctive therapy in asthma. Part 1: A review of potential mechanisms

Vitamin D deficiency (VDD) is highly prevalent worldwide. The classical role for vitamin D is to regulate calcium absorption form the gastrointestinal tract and influence bone health. Recently vitamin D receptors and vitamin D metabolic enzymes have been discovered in numerous sites systemically supporting diverse extra-skeletal roles of vitamin D, for example in asthmatic disease. Further, VDD and asthma share several common risk factors including high latitude, winter season, industrialization, poor diet, obesity, and dark skin pigmentation. Vitamin D has been demonstrated to possess potent immunomodulatory effects, including effects on T cells and B cells as well as increasing production of antimicrobial peptides (e.g. cathelicidin). This immunomodulation may lead to asthma specific clinical benefits in terms of decreased bacterial/viral infections, altered airway smooth muscle-remodeling and -function as well as modulation of response to standard anti-asthma therapy (e.g. glucocorticoids and immunotherapy). Thus, vitamin D and its deficiency have a number of biological effects that are potentially important in altering the course of disease pathogenesis and severity in asthma. The purpose of this first of a two-part review is to review potential mechanisms whereby altering vitamin D status may influence asthmatic disease.

Glucocorticoids decrease Treg cell numbers in lungs of allergic mice

Glucocorticoids have been the hallmark anti-inflammatory drug used to treat asthma. It has been shown that glucocorticoids ameliorate asthma by increasing numbers and activity of Tregs, in contrast recent data show that glucocorticoid might have an opposite effect on Treg cells from normal mice. Since Tregs are target cells that act on the resolution of asthma, the aim of this study was to elucidate the effect of glucocorticoid treatment on lung Tregs in mouse models of asthma. Allergen challenged mice were treated with either oral dexamethasone or nebulized budesonide. Broncoalveolar lavage and airway hyperresponsiveness were evaluated after allergenic challenge. Lung, thymic and lymph node cells were phenotyped on Treg through flow cytometry. Lung cytokine secretion was detected by ELISA. Although dexamethasone inhibited airway inflammation and hyperresponsiveness, improving resolution, we have found that both dexamethasone and budesonide induce a reduction of Treg numbers on lungs and lymphoid organs of allergen challenged mice. The reduction of lung Treg levels was independent of mice strain or type of allergen challenge. Our study also indicates that both glucocorticoids do not increase Treg activity through production of IL-10. Glucocorticoid systemic or localized treatment induced thymic atrophy. Taken together, our results demonstrate that glucocorticoids decrease Treg numbers and activity in different asthma mouse models, probably by reducing thymic production of T cells. Therefore, it is possible that glucocorticoids do not have beneficial effects on lung populations of Treg cells from asthmatic patients.

Medroxyprogesterone acetate differentially regulates interleukin (IL)-12 and IL-10 in a human ectocervical epithelial cell line in a glucocorticoid receptor (GR)-dependent manner

Medroxyprogesterone acetate (MPA), designed to mimic the actions of the endogenous hormone progesterone (P4), is extensively used by women as a contraceptive and in hormone replacement therapy. However, little is known about the steroid receptor-mediated molecular mechanisms of action of MPA in the female genital tract. In this study, we investigated the regulation of the pro-inflammatory cytokine, interleukin (IL)-12, and the anti-inflammatory cytokine IL-10, by MPA versus P4, in an in vitro cell culture model of the female ectocervical environment. This study shows that P4 and MPA significantly increase the expression of the IL-12p40 and IL-12p35 genes, whereas IL-10 gene expression is suppressed in a dose-dependent manner. Moreover, these effects were abrogated when reducing the glucocorticoid receptor (GR) levels with siRNA. Using a combination of chromatin immunoprecipitation (ChIP), siRNA, and re-ChIP assays, we show that recruitment of the P4- and MPA-bound GR to the IL-12p40 promoter requires CCAAT enhancer-binding protein (C/EBP)-β and nuclear factor κB (NFκB), although recruitment to the IL-10 promoter requires signal transducer and activator of transcription (STAT)-3. These results suggest that both P4 and MPA may modulate inflammation in the ectocervix via this genomic mechanism.

Risk factors for asthma exacerbation in patients presenting to an emergency unit of a national referral hospital in Kampala, Uganda

BACKGROUND

Asthma exacerbations are caused by a variety of risk factors. Reducing exposure to these risk factors improves the control of asthma and reduces medication needs. Knowledge of the particular risk factors is essential in formulating controlling and treatment protocols. This study set out to determine the risk factors for asthma exacerbations in patients presenting to the emergency unit of Mulago Hospital.

METHODS

An unmatched case-control study involving 43 cases and 43 controls was conducted from November 2011 through February 2012. Asthma patients with exacerbations presenting to Mulago hospital's emergency unit were chosen as cases. The controls were asthma patients recruited from the hospital's outpatient department who had not had an exacerbation in the past 7 days. The study variables were age, sex, level of education, adherence to treatment, exercise, upper respiratory tract infections, household pets, smoking, strong emotions, exposure to in house wood or charcoal burning, weather, use of corticosteroids, beta-blockers and non-steroidal anti-inflammatory drugs. Univariate and multivariate statistical analysis was done using SPSS version 16 to identify independent risk factors for exacerbations.

RESULTS

Lack of corticosteroid use (OR = 22.109; 95% Confidence interval 6.952 to 70.315; p < 0.001) and presence of upper respiratory tract infections (OR 4.516; CI 1.258-16.213; p = 0.018) were significantly associated with exacerbations.

CONCLUSION

Lack of corticosteroid use and upper respiratory tract infections are associated with exacerbations in asthma patients presenting to the Emergency unit of Mulago Hospital.

Microhemorrhage is an early event in the pulmonary fibrotic disease of PECAM-1 deficient FVB/n mice

Platelet Endothelial Cell Adhesion Molecule 1 (PECAM-1) deficient mice in the FVB/n strain exhibit fatal chronic pulmonary fibrotic disease. The illness occurs in the absence of a detectable pro-inflammatory event. PECAM-1 is vital to the stability of vascular permeability, leukocyte extravasation, clotting of platelets, and clearance of apoptotic cells. We show here that the spontaneous development of fibrotic disease in PECAM-1 deficient FVB/n mice is characterized by early loss of vascular integrity in pulmonary capillaries, resulting in spontaneous microbleeds. Hemosiderin-positive macrophages were found in interstitial spaces and bronchoalveolar lavage (BAL) fluid in relatively healthy animals. We also observed a gradually increasing presence of hemosiderin-positive macrophages and fibrin deposition in the advanced stages of disease, corresponding to the accumulation of collagen, IL-10 expression, and myofibroblasts expressing alpha smooth muscle actin (SMA). Together with the growing evidence that pulmonary microbleeds and coagulation play an active part in human pulmonary fibrosis, this data further supports our hypothesis that PECAM-1 expression is necessary for vascular barrier function control and regulation of homeostasis specifically, in the pulmonary environment.

Serum levels of IL-10, IL-17F and IL-33 in patients with asthma: a case-control study

OBJECTIVES

The development of inflammation in asthma involves an intricate network of cytokines that recruit and activate numerous immune cells. This study was aimed to compare serum levels of IL-10, IL-17F, and IL-33 in asthmatic patients and non-asthmatic controls and correlate cytokine levels to asthma severity and various clinical, spirometric, and laboratory variables.

METHODS

Using ELISA, serum levels of IL-10, IL-17F, and IL-33 were evaluated in 44 asthmatics (14 mild persistent, 15 moderate persistent, and 15 severe persistent) and 44 controls.

RESULTS

This is one of the first reports showing a significant difference in serum levels of asthma-associated cytokines, anti-inflammatory IL-10, and pro-inflammatory IL-17F and IL-33, in the same subset of asthmatic patients. Our results showed diminished level of IL-10 and elevated levels of IL-17F and IL-33 in asthmatics than in controls (p < 0.001). Assessment of cytokine levels between subjects of different gender, age group, and BMI showed non-significant differences. Correlation analysis of cytokine levels to clinical variables showed that IL-17F is associated negatively to FVC % predicted (forced vital capacity) and FEV1% predicted (forced expiratory volume in one second) and positively to number of allergens sensitized and FEV1 reversibility. A strong negative correlation was found between IL-10 and IL-33 levels (p = 0.001).

CONCLUSIONS

Negative correlation between IL-10 and IL-33 levels may reflect a converse relationship between anti-inflammatory and pro-inflammatory cytokines in an individually balanced pattern. The association between IL-17F level and asthmatic phenotypes such as reduced FVC and FEV1, higher degree of sensitization, and post-bronchodilator reversibility needs further assessments.

Enhanced glucocorticoid-induced leucine zipper in dendritic cells induces allergen-specific regulatory CD4(+) T-cells in respiratory allergies

BACKGROUND

Respiratory allergies rely on a defect of IL-10-secreting regulatory CD4(+) T-cells (IL-10-Tregs ) leading to excessive Th2-biased immune responses to allergens. According to clinical data, the restoration of allergen-specific IL-10-Tregs is required to control respiratory allergies and cure patients. The discovery of mechanisms involved in the generation of IL-10-Tregs will thus help to provide effective treatments. We previously demonstrated that dendritic cells (DCs) expressing high levels of the glucocorticoid-induced leucine zipper protein (GILZ) generate antigen-specific IL-10-Tregs .

OBJECTIVE

We suspect a defective expression of GILZ in the DCs of respiratory allergic patients and speculate that increasing its expression might restore immune tolerance against allergens through the induction of IL-10-Tregs .

METHODS

We assessed GILZ expression in blood DCs of patients and healthy nonallergic donors by qPCR. We compared the ability of patients' DCs to induce allergen-specific IL-10-Tregs before and after an in vivo up-regulation of GILZ expression by steroid administration, steroids being inducers of GILZ.

RESULTS

We report lower levels of GILZ in DCs of respiratory allergic patients that return to normal levels after steroid administration. We show that patients' DCs with increased levels of GILZ generate allergen-specific IL-10-Tregs again. We further confirm unequivocally that GILZ is required in patients' DCs to activate these IL-10-Tregs .

CONCLUSION

This proof of concept study shows that the re-establishment of GILZ expression in patients' DCs to normal levels restores their capacity to activate allergen-specific IL-10-Tregs . We thus highlight the up-regulation of GILZ in DCs as a new interventional approach to restore the immune tolerance to allergens.

Longitudinal assessment of high versus low levels of fractional exhaled nitric oxide among children with asthma and atopy

PURPOSE

Fractional exhaled nitric oxide (FeNO) has emerged as an important biomarker in asthma. Increasing evidence points to atopy as a confounding factor in the interpretation of elevated FeNO. We conducted a longitudinal study to understand the clinical significance of FeNO as an inflammatory biomarker.

METHODS

We identified 19 children aged 13-15 years at baseline with a significant elevation in FeNO ≥ 80 parts per billion (ppb) and randomly selected a group of children of similar age with a moderate elevation (40-79 ppb) and normal-to-low FeNO (<40 ppb). Between November 2010 and July 2011, three additional study visits were conducted.

RESULTS

Ninety-three children participated in the study. There were 16, 24, and 53 participants in the high, mid, and low FeNO groups. During 1.5 years of follow-up, mean FeNO levels were 82.6 ppb (standard deviation [SD] = 65.9) for atopic asthmatics, 50.6 ppb (SD = 42.6) for nonasthmatic atopics, 17.0 ppb (SD = 10.8) for nonatopic asthmatics, and 17.8 ppb (SD = 13.9) for nonatopic nonasthmatics (p < 0.001). FeNO levels remained stable: 63 % of the high FeNO group had a FeNO ≥ 80 across all 4 measurements and 87 % of the normal-to-low FeNO group had a FeNO of <40 across all 4 measurements. The high FeNO group also was found to have an elevation in IL-5 (p = 0.04), IL-6 (p = 0.003), IL-10 (p = 0.002), and total serum IgE (p < 0.001), after adjustment by age, sex, height, body mass index, and atopy and asthma status.

CONCLUSIONS

An elevation of FeNO appears to indicate an atopic phenotype regardless of an asthma diagnosis, clinical symptoms, or corticosteroid use. An elevation of FeNO also is associated with a systemic elevation in inflammatory cytokines.