Anti-interleukin-4 therapy

Protective effects of allantoin against ovalbumin (OVA)-induced lung inflammation in a murine model of asthma

Asthma is characterized by difficulty in breathing because of the constriction of the smooth muscles of the bronchi, as a result of inflammation. In the present study, we focus on the protective effects of allantoin against ovalbumin (OVA)-induced lung inflammation in a murine allergic model, and assess cytokine release, eosinophilia, and mucus hypersecretion. Allantoin treatment led to significant reduction in the levels of Ig(immunoglobulin)E and T-helper-2-type cytokines, such as IL(interleukin)-4 and IL-5, in bronchoalveolar lavage (BAL) fluid. Airway inflammatory-cell infiltration was remarkably alleviated in allantoin-treated asthma groups, compared with the control group. Moreover, allantoin-treated asthma groups exhibited a marked decrease in cytokine mRNA expression in lung tissues, compared with the control group. The effectiveness of allantoin was similar to that of montelukast, used as a positive control. These results support the utility of allantoin as a protective agent against asthma.

IL-4 induces cathepsin protease activity in tumor-associated macrophages to promote cancer growth and invasion

Innate immune cells can constitute a substantial proportion of the cells within the tumor microenvironment and have been associated with tumor malignancy in patients and animal models of cancer; however, the mechanisms by which they modulate cancer progression are incompletely understood. Here, we show that high levels of cathepsin protease activity are induced in the majority of macrophages in the microenvironment of pancreatic islet cancers, mammary tumors, and lung metastases during malignant progression. We further show that tumor-associated macrophage (TAM)-supplied cathepsins B and S are critical for promoting pancreatic tumor growth, angiogenesis, and invasion in vivo, and markedly enhance the invasiveness of cancer cells in culture. Finally, we demonstrate that interleukin-4 (IL-4) is responsible for inducing cathepsin activity in macrophages in vitro and in vivo. Together, these data establish IL-4 as an important regulator, and cathepsin proteases as critical mediators, of the cancer-promoting functions of TAMs.

IL-13 as a therapeutic target for respiratory disease

Interleukin-13 (IL-13) is a critical mediator of asthma pathology. On B cells, monocytes, epithelial cells, and smooth muscle cells, IL-13 acts through the IL-13Ralpha1/IL-4Ralpha complex to directly induce activation responses that contribute to atopic disease. In human populations, genetic polymorphisms in IL-13, its receptor components, or the essential signaling element STAT6, have all been associated with increased risk of atopy and asthma. Animal studies using IL-13 deficient mice, IL-13 transgenic animals, and IL-13 neutralization strategies have confirmed an essential role for this cytokine in driving major correlates of asthma pathology, including airway hyperresponsiveness (AHR), lung eosinophilia, mucus generation, and fibrosis. Ongoing studies continue to define both overlapping and distinct roles for IL-13 and the related cytokine, IL-4, in promoting asthmatic changes. Furthermore, new evidence concerning the role of the "decoy" receptor, IL-13Ralpha2, has prompted re-evaluation of the receptor forms that underlie the numerous activities of IL-13. In this review, we summarize the essential role of IL-13 in asthma, compare the relative contributions of IL-13 and IL-4 to key aspects of the asthmatic phenotype, and outline novel therapeutic strategies to target this critical cytokine.

Astragalus Membranaceus prevents airway hyperreactivity in mice related to Th2 response inhibition

AIM OF THE STUDY

Asthma is recognized as a common pulmonary disease throughout the world. To date, there has been a growing interest in herbal products in Traditional Chinese Medicine, which is considered to be effective to treat asthma. A Chinese herb Astragalus Membranaceus (AM) was found useful in treating allergic diseases. The purpose of this study is to determine whether this herbal injection could suppress allergic-induced AHR and mucus hypersecretion in allergic mice.

MATERIALS AND METHODS

A mouse model of chronic asthma was used to investigate AM injection on the airway lesions in compared with glucocorticoids. The study was conducted on mice sensitized and challenged with ovalbumin and the whole body plethsmography was performed to assess AHR. The bronchoalveolar lavage (BAL), histopathology were examined.

RESULTS

We found 28-day AM administration significantly decreased inflammatory infiltration and mucus secretion in the lung tissues of allergic mice. 28-day AM administration enhanced Ova-induced decreased IFN-gamma, and the Ova-induced elevations of IL-5 and IL-13 in BALF were prevented by 28-day injection. We also showed 28-day AM injection markedly suppressed increased AHR in allergic mice.

CONCLUSIONS

Our results indicate Astragalus Membranaceus has a potential role in treating allergic asthma.

Post-allergen challenge inhibition of poly(ADP-ribose) polymerase harbors therapeutic potential for treatment of allergic airway inflammation

BACKGROUND

Identifying therapeutic drugs that block the release or effects of T-helper type 2 (Th2) cytokines after allergen exposure is an important goal for the treatment of allergic inflammatory diseases including asthma. We recently showed, using a murine model of allergic airway inflammation, that poly(ADP-ribose) polymerase (PARP) plays an important role in the pathogenesis of asthma-related lung inflammation. PARP inhibition, by single injection of a novel inhibitor, thieno[2,3-c]isoquinolin-5-one (TIQ-A), before ovalbumin (OVA) challenge, prevented airway eosinophilia in C57BL/6 mice with concomitant suppression of Th2 cytokine production and mucus secretion.

OBJECTIVE

To evaluate the efficacy of the drug when it is given after OVA challenge for its possible therapeutic potential.

METHODS

This study was conducted using a murine model of allergic airway inflammation.

RESULTS

A single injection of TIQ-A (6 mg/kg) one or 6 h post-allergen challenge conferred similar reduction in OVA challenge-induced eosinophilia. More significantly, post-allergen challenge administration of the drug exerted even better suppression on the production of IL-4, IL-5, IL-13, and IgE and prevented airway hyperresponsiveness to inhaled-methacholine. The significant decrease in IL-13 was accompanied by a complete absence of airways mucus production indicating a potential protection against allergen-induced airway remodelling.

CONCLUSION

The coincidence of the inflammation trigger and the time of drug administration appear to be important for the drug's more pronounced protection. The observed time window for efficacy, 1 or 6 h after allergen challenge may be of great clinical interest. These findings may provide a novel therapeutic strategy for the treatment of allergic airway inflammation, including asthma.

Human C-C chemokine receptor 3 monoclonal antibody inhibits pulmonary inflammation in allergic mice

AIM

To evaluate the effect of C-C chemokine receptor 3 (CCR3) blockade on pulmonary inflammation and mucus production in allergic mice.

METHODS

We used the synthetic peptide of the CCR3 NH2-terminal as the immunizing antigen and generated murine monoclonal antibody against the human CCR3. In addition, the generated antibody was administered to mice sensitized and challenged with ovalbumin. The inflammatory cells in bronchoalveolar lavage, cytokine levels, pulmonary histopathology, and mucus secretion were examined.

RESULTS

The Western blotting analysis indicated that the generated antibody bound to CCR3 specifically. The allergic mice treated with the antihuman CCR3 antibody exhibited a significant reduction of pulmonary inflammation accompanied with the alteration of cytokine.

CONCLUSION

The antibody we generated was specific to CCR3. The inhibition of airway inflammation and mucus overproduction by the antibody suggested that the blockade of CCR3 is an appealing therapeutical target for asthma. The present research may provide an experimental basis for the further study of this agent.

Novel cytokine peptide-based vaccines: an interleukin-4 vaccine suppresses airway allergic responses in mice

BACKGROUND

Monoclonal antibodies or soluble receptors have been used to block over-produced endogenous cytokines. However, they have disadvantages of short half-lives, high costs, and possible adverse effects. Using interleukin (IL)-4 as a model target, we sought to develop a novel therapeutic strategy by constructing an IL-4 peptide-based vaccine for blocking IL-4 on a persistent basis, and to evaluate its efficacy in a mouse model of asthma.

METHODS

A peptide was selected by antigenic prediction and structure analysis of IL-4/receptor complex. The vaccine was constructed by employing truncated hepatitis B core antigen as carrier with the peptide inserted using gene engineering methods. It was then expressed, purified and identified. Prior to intraperitoneal sensitization and intranasal challenge with ovalbumin, mice were subcutaneously immunized three times with the vaccine, or the carrier or saline as controls. Serum antibodies, inflammatory cells in bronchoalveolar lavage fluids (BALF), lung histology, and responsiveness to inhaled methacholine were analyzed.

RESULTS

The vaccine presented as virus-like particles and reacted to polyclonal anti-IL-4 in Western blotting. Vaccinated mice produced high titers of IgG to IL-4. Serum ovalbumin-specific IgE, eosinophil accumulation in BALF, goblet cell hyperplasia, tissue inflammation and methacoline-induced respiratory responses were markedly suppressed in vaccinated mice with statistical significance, as compared with those in the control groups.

CONCLUSIONS

Administration of this novel IL-4 vaccine led to an overall decrease in the development of airway allergic inflammatory responses. The results indicate that cytokine peptide-based vaccines hold potential for treatment of asthma and, by extension, other diseases where over-expressed cytokines play a pivotal role in pathogenesis.

Eosinophil trafficking in allergy and asthma

Blood eosinophilia and tissue eosinophilia are characteristic features of allergic inflammation and asthma, conditions associated with prominent production of T(H)2 cytokines IL-4, IL-5, and IL-13. In this review, we will consider recent advances in our understanding of the molecular mechanisms that promote expansion and differentiation of eosinophil progenitors in bone marrow, eosinophil recruitment in response to chemokine receptor 3 agonists eosinophil transit mediated by specific ligand-receptor interactions, and prolonged survival of eosinophils in peripheral tissues. Novel rational therapies including antiselectin and antichemokine receptor modalities designed to block eosinophil development and trafficking are discussed, together with the implications of recent clinical studies that have evaluated the efficacy of humanized anti-IL-5 mAb therapy.

Immunomodulation: the future cure for allergic diseases

Allergies are the result of aberrant immune reactivity against common innocuous environmental proteins (allergens). A pivotal component of allergic pathogenesis is the generation of allergen-specific Th cells with an effector phenotype. These Th cells activate a complex immune cascade that triggers the release of potent mediators and enhances the mobilization of several inflammatory cells types, which in turn elicit the acute allergic reactions and promote the development of chronic inflammation. The current therapies for allergic diseases focus primarily on pharmacological control of symptoms and suppression of inflammation. This approach is beneficial, but not curative, since the underlying immune pathology is not inhibited. In an attempt to develop more effective therapeutic strategies, the scientific interest has been directed toward methods down-modulating the immune mechanisms that initiate and maintain the allergic cascade. Today, the only widely used disease-modifying form of allergy treatment is the specific immunotherapy with allergen extracts. More recently the use of anti-IgE has been approved for patients with allergic asthma. Other immunomodulatory methods being currently explored are the administration of microbial adjuvants that inhibit Th2 reactivity and the design of molecules that interrupt the activity of key allergic cytokines, chemokines, or other Th2 effector mediators.

Tetradecylselenoacetic acid, a PPAR ligand with antioxidant, antiinflammatory, and hypolipidemic properties

OBJECTIVE

Antioxidants protect against oxidative stress and inflammation, which, in combination with hyperlipidemia, are important mediators of atherogenesis. Here we present a selenium-substituted fatty acid, tetradecylselenoacetic acid (TSA), which is hypothesized to have antioxidant, antiinflammatory, and hypolipidemic properties.

METHODS AND RESULTS

We show that TSA exerts antioxidant properties by delaying the onset of oxidation of human low density lipoprotein (LDL), by reducing the uptake of oxidized LDL in murine macrophages, and by increasing the mRNA level of superoxide dismutase in rat liver. TSA also showed antiinflammatory effects by suppressing the release of interleukin (IL)-2 and -4, and by increasing the release of IL-10 in human blood leukocytes. In addition, TSA decreased the plasma triacylglycerol level and increased the mitochondrial fatty acid beta-oxidation in rat liver. In pigs, TSA seemed to reduce coronary artery intimal thickening after percutaneous coronary intervention. In HepG2 cells TSA activated all peroxisome proliferator-activated receptors (PPARs) in a dose-dependent manner.

CONCLUSIONS

Our data suggest that TSA exert potent antioxidant, antiinflammatory, and hypolipidemic properties, potentially involving PPAR-related mechanisms. Based on these effects, it is tempting to hypothesize that TSA could be an interesting antiatherogenic approach to atherosclerotic disorders.

Biologic therapies for the treatment of asthma

Asthma is a chronic disease of the airway whose pathogenesis involves the complex interplay between many cell types and inflammatory mediators. The mainstays of therapy, inhaled bronchodilators and corticosteroids, do not target the asthmatic airway specifically and therefore are associated with untoward side effects. Anti-IgE (omalizumab) is the only biologic therapy to have transitioned completely from bench to bedside. Other candidate therapies, such as those that alter the T-helper 1/T-helper 2 cytokine balance, interfere with inflammatory cell trafficking, or modify normal intracellular signaling cascades involved in inflammatory gene transcription, have had only limited success in human clinical trials. This article describes several potential novel biologic therapies that have been or could be investigated.

Asthma in women with endometriosis

INTRODUCTION

This study aimed to investigate asthma prevalence and severity in women with and without endometriosis.

METHODS

Before laparoscopy, asthma prevalence was evaluated in 879 women of reproductive age, undergoing surgery because of benign gynaecological conditions. Diagnosis of bronchial asthma was based on the American Thoracic Society criteria; asthma severity was classified in four categories according to the 2002 Global Initiative for Asthma guidelines. Asthmatic patients completed the Living with Asthma Questionnaire (LWAQ). Endometriosis was confirmed histologically and classified according to the revised American Fertility Society criteria.

RESULTS

There were no significant differences in age, smoking status, and other demographic and health characteristics between patients with endometriosis (n = 467) and controls (n = 412). Asthma prevalence was similar in women with (23/467, 4.9%; 95% CI, 3.1-7.3) and without (22/412, 5.3%; 95% CI, 3.4-8.0; P = 0.781) endometriosis. Asthma severity was similar in women with and without endometriosis, with 12 (52.2%) women with endometriosis and 13 (59.1%) controls being in the intermittent (mildest) degree of severity. No significant difference was observed between women with and without endometriosis in the LWAQ total score.

CONCLUSIONS

Women with endometriosis do not have an increased risk of having asthma.

Targeting memory Th2 cells for the treatment of allergic asthma

Th2 memory cells play an important role in the pathogenesis of allergic asthma. Evidence from patients and experimental models indicates that memory Th2 cells reside in the lungs during disease remission and, upon allergen exposure, become activated effectors involved in disease exacerbation. The inhibition of memory Th2 cells or their effector functions in allergic asthma influence disease progression, suggesting their importance as therapeutic targets. They are allergen specific and can potentially be suppressed or eliminated using this specificity. They have distinct activation, differentiation, cell surface phenotype, migration capacity, and effector functions that can be targeted singularly or in combination. Furthermore, memory Th2 cells residing in the lungs can be treated locally. Capitalizing on these unique attributes is important for drug development for allergic asthma. The aim of this review is to present an overview of therapeutic strategies targeting Th2 memory cells in allergic asthma, emphasizing Th2 generation, differentiation, activation, migration, effector function, and survival.