Salmeterol inhibits interferon-gamma and interleukin-4 production by human peripheral blood mononuclear cells

Efficacy of salmeterol and magnesium isoglycyrrhizinate combination treatment in rats with chronic obstructive pulmonary disease

The most classic treatment recommended in the current chronic obstructive pulmonary disease (COPD) guidelines is glucocorticoid and β2 receptor agonist combination, such as salmeterol xinafoate and fluticasone propionate (Sal/Flu), causing many adverse reactions due to hormones. Magnesium isoglycyrrhizinate (MgIG) is an anti-inflammatory glycyrrhizic acid preparation for treating chronic inflammation, contributing to its structure is similar to steroidal anti-inflammatory drugs. In this study, we successfully established COPD rat model by endotracheal-atomized lipopolysaccharide exposure and cigarette smoke induction, as characterized by lung function decline. We discovered that salmeterol xinafoate/MgIG combination could alleviated lung inflammation infiltration, airway wall thickness (AWT) and the secretion of bronchial mucin MUC5AC of COPD rats more than salmeterol xinafoate, MgIG, or salmeterol xinafoate and fluticasone propionate treatment did, as well as reduced inflammatory cells (white blood cells, neutrophils and lymphocytes) accumulation in bronchoalveolar lavage fluid and decreased TNF-α, IL-6 and IL-1β production in the serum of COPD rats. Finally, we found that Moreover, the mechanism involved might be related to the suppression of JAK/STAT signaling pathway. Overall, our studies suggested that MgIG might be a potential alternative adjuvant drug for fluticasone propionate for the clinical treatment of patients with COPD.

Molecular mechanisms underlying β-adrenergic receptor-mediated cross-talk between sympathetic neurons and immune cells

Cross-talk between the sympathetic nervous system (SNS) and immune system is vital for health and well-being. Infection, tissue injury and inflammation raise firing rates of sympathetic nerves, increasing their release of norepinephrine (NE) in lymphoid organs and tissues. NE stimulation of β2-adrenergic receptors (ARs) in immune cells activates the cAMP-protein kinase A (PKA) intracellular signaling pathway, a pathway that interfaces with other signaling pathways that regulate proliferation, differentiation, maturation and effector functions in immune cells. Immune-SNS cross-talk is required to maintain homeostasis under normal conditions, to develop an immune response of appropriate magnitude after injury or immune challenge, and subsequently restore homeostasis. Typically, β2-AR-induced cAMP is immunosuppressive. However, many studies report actions of β2-AR stimulation in immune cells that are inconsistent with typical cAMP-PKA signal transduction. Research during the last decade in non-immune organs, has unveiled novel alternative signaling mechanisms induced by β2-AR activation, such as a signaling switch from cAMP-PKA to mitogen-activated protein kinase (MAPK) pathways. If alternative signaling occurs in immune cells, it may explain inconsistent findings of sympathetic regulation of immune function. Here, we review β2-AR signaling, assess the available evidence for alternative signaling in immune cells, and provide insight into the circumstances necessary for "signal switching" in immune cells.

Omalizumab attenuates airway inflammation and interleukin-5 production by mononuclear cells in patients with severe allergic asthma

BACKGROUND

Omalizumab, an anti-immunoglobulin E monoclonal antibody, has shown an inhibitory effect on airway inflammation, which may be associated with clinical improvement of severe asthma. This study evaluated changes in airway inflammation and cytokine release by the peripheral blood mononuclear cells (PBMCs) of Japanese patients with severe asthma after administration of omalizumab.

METHODS

Sixteen Japanese patients with severe asthma who were allergic to house-dust mites were enrolled in this study. Eight received omalizumab every 2 or 4 weeks for 16 weeks, and 8 control subjects were treated with conventional drug treatment. Changes in clinical scores for sputum eosinophils and levels of fraction of exhaled nitric oxide (FeNO) were measured at the time of enrollment and at week 16. Cytokines from PBMCs stimulated by house-dust mite (Dermatophagoides farinae) or ionomycin/phorbol myristate acetate (PMA) were measured at baseline and at week 16.

RESULTS

In the omalizumab-treated group, decreases in sputum eosinophils and FeNO were observed following treatment. Furthermore, the ex vivo production of interleukin (IL)-5 by PBMCs in response to both mite allergen and ionomycin/PMA decreased significantly. In contrast, interferon (IFN)-γ production was unchanged. There were no changes in any of the parameters observed in the control group.

CONCLUSION

Omalizumab exerts inhibitory effects on airway inflammation in Japanese patients with severe allergic asthma. This treatment attenuates production of IL-5 by PBMCs stimulated with both a specific allergen and a nonspecific activator. Reduction of the Th2 inflammatory cascade likely contributes to clinical benefits; however, further studies are required to clarify these results due to the small sample size in this study.

Effects of β(2) Agonists, Corticosteroids, and Novel Therapies on Rhinovirus-Induced Cytokine Release and Rhinovirus Replication in Primary Airway Fibroblasts

Rhinovirus-(RV-) induced asthma exacerbations account for high asthma-related health costs and morbidity in Australia. The cellular mechanism underlying this pathology is likely the result of RV-induced nuclear-factor-kappa-B-(NF-κB-) dependent inflammation. NF-κB may also be important in RV replication as inhibition of NF-κB inhibits replication of other viruses such as human immunodeficiency virus and cytomegalovirus. To establish the role of NF-κB inhibitors in RV-induced IL- 6 and IL-8 and RV replication, we used pharmacological inhibitors of NF-κB, and steroids and/or β(2) agonists were used for comparison. Primary human lung fibroblasts were infected with RV-16 in the presence of NF-κB inhibitors: BAY-117085 and dimethyl fumarate; β(2) agonist: salmeterol; and/or corticosteroids: dexamethasone; fluticasone. RV-induced IL-6 and IL-8 and RV replication were assessed using ELISAs and virus titration assays. RV replicated and increased IL-6 and IL-8 release. Salmeterol increased, while dexamethasone and fluticasone decreased RV-induced IL-6 and IL-8 (P<0.05). The NF-κB inhibitor BAY-117085 inhibited only RV-induced IL-6 (P<0.05) and dimethyl fumarate did not alter RV-induced IL-6 and IL-8. Dimethylfumarate increased RV replication whilst other drugs did not alter RV replication. These data suggest that inhibition of NF-κB alone is unlikely to be an effective treatment compared to current asthma therapeutics.

Antiinflammatory effects of long-acting beta2-agonists in patients with asthma: a systematic review and metaanalysis

BACKGROUND

Long-acting beta(2)-agonists (LABAs) are recommended as add-on therapy to antiinflammatory treatment in patients with chronic persistent asthma. Results from individual studies evaluating the in vivo antiinflammatory effect of LABAs are conflicting. The purpose of this metaanalysis was to determine whether LABAs have an in vivo antiinflammatory effect compared to placebo and whether the addition of a LABA to therapy with inhaled corticosteroids (ICSs) has a synergistic or additive antiinflammatory effect.

METHODS

A systematic search was performed of online databases for randomized controlled trials evaluating the antiinflammatory effects of the following: (1) LABAs compared to placebo; and (2) a LABA plus ICS vs ICS alone in adults and children with asthma. Inflammatory outcome measures included cell counts and markers of cell activation in sputum, BAL fluid, bronchial biopsy specimens, serum, and exhaled nitric oxide (ENO). Data were independently extracted by two study investigators and analyzed to generate standardized mean differences using either a fixed or random-effects metaanalysis depending on the degree of heterogeneity.

RESULTS

Thirty-two studies (n = 1,105 participants) met the inclusion criteria. The mean number of participants and mean number of studies for each inflammatory outcome in the metaanalysis was 113.1 (SD, 46.2) and 3.5 (SD, 1.3), respectively. There was no effect of LABA therapy on sputum, BAL fluid, or mucosal inflammatory cells in adults or in children. LABA therapy decreased ENO levels and BAL fluid albumin levels in adults. In children, LABA therapy was associated with a small decrease in serum eosinophils and interleukin-4.

CONCLUSION

LABA therapy does not appear to have any clinically important antiinflammatory or proinflammatory effect. LABA therapy decreases BAL fluid albumin levels, suggesting a possible modulating effect on microvascular leakage.

Toll-like receptor-4 mediates cigarette smoke-induced cytokine production by human macrophages

BACKGROUND

The major risk factor for the development of COPD is cigarette smoking. Smoking causes activation of resident cells and the recruitment of inflammatory cells into the lungs, which leads to release of pro-inflammatory cytokines, chemotactic factors, oxygen radicals and proteases. In the present study evidence is found for a new cellular mechanism that refers to a link between smoking and inflammation in lungs.

METHODS

Employing human monocyte-derived macrophages, different techniques including FACS analysis, Cytometric Bead Array Assay and ELISA were achieved to evaluate the effects of CS on pro-inflammatory cytokine secretion including IL-8. Then, Toll-like receptor neutralization was performed to study the involvement of Toll-like receptor-4 in IL-8 production. Finally, signaling pathways in macrophages after exposure to CS medium were investigated performing ELISA and Western analysis.

RESULTS

We demonstrate that especially human monocytes are sensitive to produce IL-8 upon cigarette smoke stimulation compared to lymphocytes or neutrophils. Moreover, monocyte-derived macrophages produce high amounts of the cytokine. The IL-8 production is dependent on Toll-like receptor 4 stimulation and LPS is not involved. Further research resolved the cellular mechanism by which cigarette smoke induces cytokine production in monocyte-derived macrophages. Cigarette smoke causes subsequently a concentration-dependent phosphorylation of IRAK and degradation of TRAF6. Moreover, IkappaBalpha was phosphorylated which suggests involvement of NF-kappaB. In addition, NFkappaB-inhibitor blocked cigarette smoke-induced IL-8 production.

CONCLUSION

These findings link cigarette smoke to inflammation and lead to new insights/therapeutic strategies in the pathogenesis of lung emphysema.

Interleukin-10-secreting "regulatory" T cells induced by glucocorticoids and beta2-agonists

Greater clinical benefit in controlling the symptoms of asthma is frequently observed through combining moderate doses of inhaled glucocorticoids together with long-acting beta(2)-agonists, as compared with increasing glucocorticoid dosage alone. To address in vitro whether glucocorticoids plus beta(2)-agonists, compared with glucocorticoids alone, have greater inhibitory activity on CD4+ T cell responses to allergen, peripheral blood CD4+ T cell responses to allergen were compared in the presence or absence of the glucocorticoid fluticasone proprionate and the short- and long-acting beta(2)-agonists salbutamol and salmeterol, respectively. Fluticasone proprionate inhibited interleukin (IL)-5 and IL-13 and enhanced IL-10 synthesis in allergen-stimulated cultures in a concentration-dependent manner. Salmeterol, but not salbutamol, inhibited IL-5 and IL-13 and enhanced IL-10 synthesis in these cultures. When used in combination the two drugs demonstrated an additive effect on this pattern of cytokine production. Allergen-specific T cell lines induced in the presence of salmeterol and fluticasone proprionate inhibited IL-5 and IL-13 production by allergen-specific Th2 cell lines in an IL-10-dependent manner. Thus fluticasone proprionate and salmeterol increased IL-10 and reduced Th2 cytokine synthesis additively in allergen stimulated human CD4+ T cells.

A randomized, double-blind trial of the effect of treatment with formoterol on clinical and inflammatory parameters of asthma in children

BACKGROUND

In addition to their bronchodilating effect, long-acting inhaled beta-agonists have recently been shown to have some anti-inflammatory properties.

OBJECTIVE

The purpose of this study was to evaluate the effect of formoterol on inflammatory mediators in children.

METHODS

In this double-blind, randomized, placebo-controlled trial, 34 children, aged 6 to 18 years, with moderate atopic asthma, were randomly allocated to receive formoterol or matching placebo for 4 weeks. The primary endpoint of this study was to determine changes in serum levels of inflammatory markers after treatment with formoterol; secondary endpoints included clinical efficacy and bronchial hyperreactivity. The following parameters were measured: symptom score, forced expiratory volume in 1 second (FEV1), provocative concentration of histamine causing a 20% fall in FEV1 (PC20) for histamine and peripheral blood eosinophil count, serum levels of eosinophil cationic protein (ECP), soluble receptor of interleukin-2 (sIL-2R), level of interleukin-4 (IL-4), level of soluble intercellular adhesion molecule-1 (ICAM-1), and immunoglobulin E (IgE) level before and after treatment.

RESULTS

Compared with placebo, treatment with formoterol significantly improved lung function. The mean value of FEV1 changed from 74% of predicted value before treatment to 80% of predicted value after treatment (P < 0.001). The mean concentration of eosinophil blood count before and after treatment was 379 and 310 cells/mm3 (P = 0.035); ECP was 93 and 83 mcg/L; and serum IL-4 was 0.13 and 0.11 pg/mL (P = 0.001). There was no significant difference between formoterol and placebo recipients in PC20H, and serum concentration of sIL-2R, sICAM-1, or IgE after treatment. The group that received formoterol showed improvement in pulmonary function as measured by FEV1 (P < 0.001), and PC20H (P = 0.04) after 4 weeks of treatment. These patients also showed improvement of clinical symptoms (P < 0.001). Serum marker measurements in the formoterol group showed decreased concentrations of eosinophil blood count, ECP, and IL-4, but there was no difference in before and after measurements of sIL-2R, sICAM-1, and IgE.

CONCLUSIONS

These results indicate that formoterol has measurable anti-inflammatory properties and can diminish asthma symptoms and bronchial hyperreactivity.

Modulation of T-cell function by (R)- and (S)-isomers of albuterol: anti-inflammatory influences of (R)-isomers are negated in the presence of the (S)-isomer

BACKGROUND

beta(2)-Adrenergic agonists interact with specific receptors on T lymphocytes to mediate anti-inflammatory activities. However, anti-inflammatory effects are not observed when beta(2)-adrenergic agonists are administered in vivo as racemates.

OBJECTIVE

We hypothesized that anti-inflammatory influences are mediated by the (R)-isomer and are masked in the additional presence of the (S)-isomer.

METHODS

Antigen-specific T-cell lines were generated in the presence of recombinant human IL-2 and tetanus with or without varying concentrations of (R)- and (S)-isomers of albuterol alone or in combination. Parallel lines were generated in the presence of propranolol. Cells were briefly pulsed with PHA and evaluated for proliferation, apoptosis, and cytokine secretion.

RESULTS

(R)-Albuterol significantly inhibited T-cell proliferation (77.0% +/- 9.7% of control at 10(-8) mol/L and 61.1% +/- 9.0% at 10(-7) mol/L). No influence was observed with (S)-albuterol alone. However, the addition of (S)-albuterol to (R)-albuterol mediated a dose-dependent increase in proliferation. At equivalent concentrations of the 2 isomers, proliferation was unchanged from the control, whereas at 10(-6) mol/L (S)-albuterol, proliferation was enhanced. Both the inhibitory effects of (R)-albuterol alone and the stimulating influence of (R)- plus (S)-albuterol were blocked in the additional presence of propranolol. (R)-Albuterol at 10(-8) mol/L inhibited IL-2 and IFN-gamma production. Racemic albuterol (10(-8) mol/L each) had no influence on cytokine production; however, the combination of 10(-8) mol/L (R)-albuterol with 10(-6) (S)-albuterol stimulated production of IL-2 and IL-13. No effects were observed on apoptosis or cell viability.

CONCLUSION

These studies confirm the beta-adrenergic receptor-specific anti-inflammatory effects of (R)-albuterol. The racemate had minimal influences on proliferation or cytokine production. The presence of excess (S)-albuterol resulted in proinflammatory influences. We hypothesize that the (S)-isomer functions as an inverse agonist to switch the function of the beta(2)-adrenergic receptor.

Beta2-agonist exerts differential effects on the development of cord blood T cells but not on peripheral blood T cells

Asthma is a chronic inflammatory disease characterized by reversible airway obstruction caused by edematous airway lining, thickened mucosal secretions, and smooth muscle constriction. Beta2-adrenoceptor agonists are widely used in the treatment of bronchial asthma because of their ability to induce relaxation of airway smooth muscle. Evidence indicates that desensitization and down-regulation of beta-adrenoceptors occurs in long-term beta2-agonist therapy, and these medications were thought to cause increased severity of, and mortality in, asthma. The purpose of this study was to delineate further the potential adverse effects of beta2-agonists on the development of T lymphocytes. T cells isolated from umbilical cord blood and adult peripheral blood were cultured in the presence of salbutamol. Intracellular staining with fluorescence-labeled antibodies was used to differentiate the frequency of type 1 T-helper (Th1) and type 2 T-helper (Th2) cells. The results showed a statistically significant inverse relationship between the concentration of salbutamol and the ratio of Th1 over Th2 on cord blood T cells. However, this trend was not observed in adult peripheral blood T cells. The data revealed another potential adverse effect in which chronic beta2-agonist exposure predisposed differentiation of T lymphocytes towards Th2 while that of Th1 was relatively suppressed, especially in cord blood T cells. Hence, beta2-agonists, despite their effect in symptomatic rescue in asthma, should not be used indiscriminately as long-term therapeutic agents.

The effects of noradrenaline and alpha-2 adrenoceptor agents on the production of monocytic products

There are some reports that catecholamines may modulate the production of monocytic cytokines such as interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF alpha). The present study was carried out in order to examine the effects of noradrenaline (10(-5), 10(-6) and 10(-7) M), clonidine (10(-5), 10(-6) and 10(-7) M), an alpha2-adrenoceptor agonist, and yohimbine (10(-5), 10(-6) and 10(-7) M), an alpha 2-adrenoceptor antagonist, on the production of IL-6, the IL-1 receptor antagonist (IL-1RA) and TNF alpha by stimulated whole blood of normal humans. We measured the in vitro production of IL-6, TNF alpha and IL-1RA by stimulated (phytohemagglutinin+lipopolysaccharide), diluted whole blood of 16 normal volunteers. The results show that noradrenaline, 10(-5) M, significantly suppressed the production of IL-6; noradrenaline, 10(-5) and 10(-6) M, significantly suppressed the production of IL-1RA and TNF alpha; clonidine, 10(-5) M, significantly suppressed the production of TNF alpha; and yohimbine, 10(-5) and 10(-6) M, significantly suppressed the production of IL-1RA. It is concluded that (1) noradrenaline has significant negative immunoregulatory effects in humans through suppression of the production of (monocytic) proinflammatory cytokines, e.g. IL-6 and TNF alpha, and (2) the suppression of the production of TNF alpha may be related to alpha(2)-adrenoceptor-related mechanisms.

Beta-adrenergic modulation of human type-1/type-2 cytokine balance

BACKGROUND

Neuroendocrine mediators are increasingly recognized as immunomodulatory agents. Lymphocytes and monocytes express receptors for a variety of neuroendocrine mediators, including catecholamines. It has been reported that beta-adrenergic agonists decrease IFN-gamma production, with varying effects on IL-4 and IL-5 production.

OBJECTIVE

Our purpose was to determine the effects of catecholamines (including beta-adrenergic agonists) on the type-1/type-2 cytokine balance in tetanus-stimulated human PBMCs.

METHOD

Human PBMCs were stimulated with tetanus in the presence of epinephrine (EPI), norepinephrine, or terbutaline. IFN-gamma, IL-4, IL-5, and IL-10 levels in the supernatants were determined by ELISA.

RESULTS

PBMCs stimulated in the presence of EPI produced decreased levels of IFN-gamma and increased levels of IL-10, IL-4, and IL-5. A small decrease in IFN-gamma production and an increase in IL-10, IL-4, and IL-5 production were also observed with norepinephrine. Terbutaline induced similar alterations in the type-1/type-2 cytokine balance compared with EPI, indicating that the beta(2)adrenergic receptor is involved in these cytokine alterations. Furthermore, these cytokine alterations were blocked by propranolol. Finally, IL-12p70 prevented the cytokine alterations, suggesting that the mechanism of beta-adrenergic-induced cytokine alterations involves a decrease in IL-12.

CONCLUSION

beta-Adrenergic agonists induce a shift in the human type-1/type-2 cytokine balance toward a type-2 response. These data provide a potential mechanism to explain the paradoxical increase in asthma morbidity and mortality associated with the chronic use of scheduled dosing of short-acting beta-adrenergic agonists.

Effect of beta-agonists on production of cytokines by activated T cells obtained from asthmatic patients and normal subjects

Intracellular levels of cAMP were found to regulate T cell activity. We examined whether beta2-agonists altered cytokine production and cyclic adenosine monophosphate (cAMP) accumulation in concanavalin A (ConA)-activated peripheral T cells from asthmatic patients. Procaterol and isoproterenol weakly decreased the ConA-elicited interleukin (IL)-4 and IL-5 secretion; however, the inhibitory effect of procaterol on the ConA-induced IL-2 secretion was inferior to that of isoproterenol in normal controls and was little in asthmatics. The intracellular accumulation of cAMP by procaterol was not altered compared with that by isoproterenol. Results suggest that there is a qualitative difference between procaterol- and isoproterenol-induced cAMP accumulation in T cells.