Nebulized anti-IL-13 monoclonal antibody Fab' fragment reduces allergen-induced asthma

Effects of biological therapies on patients with Type-2 high asthma and comorbid obesity

Over 20 million adults and 6 million children in the United States (US) have asthma, a chronic respiratory disease characterized by airway inflammation, bronchoconstriction, and mucus hypersecretion. Obesity, another highly prevalent disease in the US, is a major risk factor for asthma and a significant cause of diminished asthma control, increased submucosal eosinophilia, and reduced quality of life. A large subgroup of these patients experiences severe symptoms and recurrent exacerbations despite maximal dosage of standard asthma therapies. In the past two decades, the development of biological therapies has revolutionized the field and advanced our understanding of type 2 inflammatory biomarkers. However, patients with obesity and comorbid asthma are not principally considered in clinical trials of biologics. Large landmark cluster analyses of patients with asthma have consistently identified specific asthma phenotypes that associate with obesity but may be differentiated by age of asthma onset and inflammatory cell profiles in sputum. These patterns suggest that biologic processes driving asthma pathology are heterogenous among patients with obesity. The biological mechanisms driving pathology in patients with asthma and comorbid obesity are not well understood and likely multifactorial. Future research needs to be done to elicit the cellular and metabolic functions in the relationship of obesity and asthma to yield the best treatment options for this multiplex condition. In this review, we explore the key features of type 2 inflammation in asthma and discuss the effectiveness, safety profile, and research gaps regarding the currently approved biological therapies in asthma patients with obesity.

Aerosol pulmonary immune engineering

Aerosolization of immunotherapies poses incredible potential for manipulating the local mucosal-specific microenvironment, engaging specialized pulmonary cellular defenders, and accessing mucosal associated lymphoid tissue to redirect systemic adaptive and memory responses. In this review, we breakdown key inhalable immunoengineering strategies for chronic, genetic, and infection-based inflammatory pulmonary disorders, encompassing the historic use of immunomodulatory agents, the transition to biological inspired or derived treatments, and novel approaches of complexing these materials into drug delivery vehicles for enhanced release outcomes. Alongside a brief description of key immune targets, fundamentals of aerosol drug delivery, and preclinical pulmonary models for immune response, we survey recent advances of inhaled immunotherapy platforms, ranging from small molecules and biologics to particulates and cell therapies, as well as prophylactic vaccines. In each section, we address the formulation design constraints for aerosol delivery as well as advantages for each platform in driving desirable immune modifications. Finally, prospects of clinical translation and outlook for inhaled immune engineering are discussed.

Strategies for overcoming the biological barriers associated with the administration of inhaled monoclonal antibodies for lung diseases

INTRODUCTION

Monoclonal antibodies (mAbs) should be administered by inhalation rather than parenterally to improve their efficiency in lung diseases. However, the pulmonary administration of mAbs in terms of aerosol technology and the formulation for inhalation is difficult.

AREAS COVERED

The feasible or suitable strategies for overcoming the barriers associated with administering mAbs are described.

EXPERT OPINION

Providing mAbs via inhalation to individuals with lung disorders is still difficult. However, inhalation is a desirable method for mAb delivery. Inhaled mAb production needs to be well thought out. The illness, the patient group(s), the therapeutic molecule selected, its interaction with the biological barriers in the lungs, the formulation, excipients, and administration systems must all be thoroughly investigated. Therefore, to create inhaled mAbs that are stable and efficacious, it will be essential to thoroughly examine the problems linked to instability and protein aggregation. More excipients will also need to be manufactured, expanding the range of formulation design choices. Another crucial requirement is for novel carriers for topical delivery to the lungs since carriers might significantly enhance proteins' stability and pharmacokinetic profile.

Inhaled drug delivery for the targeted treatment of asthma

Asthma is a chronic lung disease affecting millions worldwide. While classically acknowledged to result from allergen-driven type 2 inflammatory responses leading to IgE and cytokine production and the influx of immune cells such as mast cells and eosinophils, the wide range in asthmatic pathobiological subtypes lead to highly variable responses to anti-inflammatory therapies. Thus, there is a need to develop patient-specific therapies capable of addressing the full spectrum of asthmatic lung disease. Moreover, delivery of targeted treatments for asthma directly to the lung may help to maximize therapeutic benefit, but challenges remain in design of effective formulations for the inhaled route. In this review, we discuss the current understanding of asthmatic disease progression as well as genetic and epigenetic disease modifiers associated with asthma severity and exacerbation of disease. We also overview the limitations of clinically available treatments for asthma and discuss pre-clinical models of asthma used to evaluate new therapies. Based on the shortcomings of existing treatments, we highlight recent advances and new approaches to treat asthma via inhalation for monoclonal antibody delivery, mucolytic therapy to target airway mucus hypersecretion and gene therapies to address underlying drivers of disease. Finally, we conclude with discussion on the prospects for an inhaled vaccine to prevent asthma.

Pericytes: The lung-forgotten cell type

Pericytes are a heterogeneous population of mesenchymal cells located on the abluminal surface of microvessels, where they provide structural and biochemical support. Pericytes have been implicated in numerous lung diseases including pulmonary arterial hypertension (PAH) and allergic asthma due to their ability to differentiate into scar-forming myofibroblasts, leading to collagen deposition and matrix remodelling and thus driving tissue fibrosis. Pericyte-extracellular matrix interactions as well as other biochemical cues play crucial roles in these processes. In this review, we give an overview of lung pericytes, the key pro-fibrotic mediators they interact with, and detail recent advances in preclinical studies on how pericytes are disrupted and contribute to lung diseases including PAH, allergic asthma, and chronic obstructive pulmonary disease (COPD). Several recent studies using mouse models of PAH have demonstrated that pericytes contribute to these pathological events; efforts are currently underway to mitigate pericyte dysfunction in PAH by targeting the TGF-β, CXCR7, and CXCR4 signalling pathways. In allergic asthma, the dissociation of pericytes from the endothelium of blood vessels and their migration towards inflamed areas of the airway contribute to the characteristic airway remodelling observed in allergic asthma. Although several factors have been suggested to influence this migration such as TGF-β, IL-4, IL-13, and periostin, recent evidence points to the CXCL12/CXCR4 pathway as a potential therapeutic target. Pericytes might also play an essential role in lung dysfunction in response to ageing, as they are responsive to environmental risk factors such as cigarette smoke and air pollutants, which are the main drivers of COPD. However, there is currently no direct evidence delineating the contribution of pericytes to COPD pathology. Although there is a lack of human clinical data, the recent available evidence derived from in vitro and animal-based models shows that pericytes play important roles in the initiation and maintenance of chronic lung diseases and are amenable to pharmacological interventions. Therefore, further studies in this field are required to elucidate if targeting pericytes can treat lung diseases.

Delivery technology of inhaled therapy for asthma and COPD

Inhaled therapy is the cornerstone of the management of asthma and chronic obstructive pulmonary disease (COPD). Drugs such as bronchodilators and corticosteroids are administered directly to the airways for local effect and rapid onset of action while systemic exposure and side effects are minimized. There are four major types of inhaler devices used clinically to generate aerosols for inhalation, namely, pressurized metered-dose inhalers (pMDIs), nebulizers, Soft Mist™ inhalers (SMIs) and dry powder inhalers (DPIs). Each of them has its own unique characteristics that can target different patient groups. For instance, patients' inhaler technique is critical for pMDIs and SMIs to achieve proper drug deposition in the lung, which could be challenging for some patients. Nebulizers are designed to deliver aerosols to patients during tidal breathing, but they require electricity to operate and are less portable than other devices. DPIs are the only device that delivers aerosols in dry powder form with better stability, but they rely on patients' inspiration effort for powder dispersion, rendering them unsuitable for patients with compromised lung function. Choosing a device that can cater for the need of individual patient is paramount for effective inhaled therapy. This chapter provides an overview of inhaled therapy for the management of asthma and COPD. The operation principles, merits and limitations of different delivery technologies are examined. Looking ahead, the challenges of delivering novel therapeutics such as biologics through the pulmonary route are also discussed.

Monoclonal antibodies in the management of asthma: Dead ends, current status and future perspectives

Patients with moderate-to-severe asthma may now be treated using a variety of monoclonal antibodies that target key inflammatory cytokines involved in disease pathogenesis. Existing clinical data on anti-IgE, anti-IL-5 and other immunological pathways indicate these therapies to offer reduced exacerbation rates, improved lung function, greater asthma control and better quality of life. However, as several patients still do not achieve satisfactory clinical response with the antibodies available, many more biologics, aiming different immunological pathways, are under evaluation. This review summarizes recent data on existing and potential monoclonal antibodies in asthma. Recent advances have resulted in the registration of a new antibody targeting TSLP (tezepelumab), with others being under development. Some of the researched monoclonal antibodies (e.g. anti-IL-13 tralokinumab and lebrikizumab or anti-IL-17A secukinumab) have shown optimistic results in preliminary research; however, these have been discontinued in asthma clinical research. In addition, as available monoclonal antibody treatments have shown little benefit among patients with T₂-low asthma, research continues in this area, with several antibodies in development. This article summarizes the available pre-clinical and clinical data on new and emerging drugs for treating severe asthma, discusses discontinued treatments and outlines future directions in this area.

Alternative Routes of Administration for Therapeutic Antibodies—State of the Art

Background: For the past two decades, there has been a huge expansion in the development of therapeutic antibodies, with 6 to 10 novel entities approved each year. Around 70% of these Abs are delivered through IV injection, a mode of administration allowing rapid and systemic delivery of the drug. However, according to the evidence presented in the literature, beyond the reduction of invasiveness, a better efficacy can be achieved with local delivery. Consequently, efforts have been made toward the development of innovative methods of administration, and in the formulation and engineering of novel Abs to improve their therapeutic index. Objective: This review presents an overview of the routes of administration used to deliver Abs, different from the IV route, whether approved or in the clinical evaluation stage. We provide a description of the physical and biological fundamentals for each route of administration, highlighting their relevance with examples of clinically-relevant Abs, and discussing their strengths and limitations. Methods: We reviewed and analyzed the current literature, published as of the 1 April 2022 using MEDLINE and EMBASE databases, as well as the FDA and EMA websites. Ongoing trials were identified using clinicaltrials.gov. Publications and data were identified using a list of general keywords. Conclusions: Apart from the most commonly used IV route, topical delivery of Abs has shown clinical successes, improving drug bioavailability and efficacy while reducing side-effects. However, additional research is necessary to understand the consequences of biological barriers associated with local delivery for Ab partitioning, in order to optimize delivery methods and devices, and to adapt Ab formulation to local delivery. Novel modes of administration for Abs might in fine allow a better support to patients, especially in the context of chronic diseases, as well as a reduction of the treatment cost.

Development of Neutralizing Multimeric Nanobody Constructs Directed against IL-13: From Immunization to Lead Optimization

IL-13 is a pleiotropic cytokine mainly secreted by Th2 cells. It reacts with many different types of cells involved in allergy, inflammation, and fibrosis, e.g., mastocytes, B cells, and fibroblasts. The role of IL-13 in conditions involving one or several of these phenotypes has therefore been extensively investigated. The inhibition of this cytokine in animal models for various pathologies yielded highly promising results. However, most human trials relying on anti-IL-13 conventional mAbs have failed to achieve a significant improvement of the envisaged disorders. Where some studies might have suffered from several weaknesses, the strategies themselves, such as targeting only IL-13 using conventional mAbs or employing a systemic administration, could be questioned. Nanobodies are recombinant Ag-binding fragments derived from the variable part of H chain-only Abs occurring in Camelidae. Thanks to their single-domain structure, small size (≈15 kDa), good stability, and solubility, they can be engineered into multispecific constructs for combined therapies or for use in new strategies such as formulations for local administration, e.g., pulmonary administration. In this study, we describe the generation of 38 nanobodies that can be subdivided into five CDR3 families. Nine nanobodies were found to have a good affinity profile (K_D = 1-200 nM), but none were able to strongly inhibit IL-13 biological activity in vitro (IC₅₀ > 50 µM: HEK-Blue IL-13/IL-4 cells). Multimeric constructs were therefore designed from these inhibitors and resulted in an up to 36-fold improvement in affinity and up to 300-fold enhancement of the biological activity while conserving a high specificity toward IL-13.

Therapeutic antibodies - natural and pathological barriers and strategies to overcome them

Antibody-based therapeutics have become a major class of therapeutics with over 120 recombinant antibodies approved or under review in the EU or US. This therapeutic class has experienced a remarkable expansion with an expected acceleration in 2021-2022 due to the extraordinary global response to SARS-CoV2 pandemic and the public disclosure of over a hundred anti-SARS-CoV2 antibodies. Mainly delivered intravenously, alternative delivery routes have emerged to improve antibody therapeutic index and patient comfort. A major hurdle for antibody delivery and efficacy as well as the development of alternative administration routes, is to understand the different natural and pathological barriers that antibodies face as soon as they enter the body up to the moment they bind to their target antigen. In this review, we discuss the well-known and more under-investigated extracellular and cellular barriers faced by antibodies. We also discuss some of the strategies developed in the recent years to overcome these barriers and increase antibody delivery to its site of action. A better understanding of the biological barriers that antibodies have to face will allow the optimization of antibody delivery near its target. This opens the way to the development of improved therapy with less systemic side effects and increased patients' adherence to the treatment.

Inhalation monoclonal antibody therapy: a new way to treat and manage respiratory infections

The route of administration of a therapeutic agent has a substantial impact on its success. Therapeutic antibodies are usually administered systemically, either directly by intravenous route, or indirectly by intramuscular or subcutaneous injection. However, treatment of diseases contained within a specific tissue necessitates a better alternate route of administration for targeting localised infections. Inhalation is a promising non-invasive strategy for antibody delivery to treat respiratory maladies because it provides higher concentrations of antibody in the respiratory airways overcoming the constraints of entry through systemic circulation and uncertainity in the amount reaching the target tissue. The nasal drug delivery route is one of the extensively researched modes of administration, and nasal sprays for molecular drugs are deemed successful and are presently commercially marketed. This review highlights the current state and future prospects of inhaled therapies, with an emphasis on the use of monoclonal antibodies for the treatment of respiratory infections, as well as an overview of their importance, practical challenges, and clinical trial outcomes.Key points• Immunologic strategies for preventing mucosal transmission of respiratory pathogens.• Mucosal-mediated immunoprophylaxis could play a major role in COVID-19 prevention.• Applications of monoclonal antibodies in passive immunisation.

Oral inhalation for delivery of proteins and peptides to the lungs

Oral inhalation is the preferred route for delivery of small molecules to the lungs, because high tissue levels can be achieved shortly after application. Biologics are mainly administered by intravenous injection but inhalation might be beneficial for the treatment of lung diseases (e.g. asthma). This review discusses biological and pharmaceutical challenges for delivery of biologics and describes promising candidates. Insufficient stability of the proteins during aerosolization and the biological environment of the lung are the main obstacles for pulmonary delivery of biologics. Novel nebulizers will improve delivery by inducing less shear stress and administration as dry powder appears suitable for delivery of biologics. Other promising strategies include pegylation and development of antibody fragments, while carrier-encapsulated systems currently play no major role in pulmonary delivery of biologics for lung disease. While development of various biologics has been halted or has shown little effects, AIR DNase, alpha1-proteinase inhibitor, recombinant neuraminidase, and heparin are currently being evaluated in phase III trials. Several biologics are being tested for the treatment of coronavirus disease (COVID)-19, and it is expected that these trials will lead to improvements in pulmonary delivery of biologics.

Pulmonary Delivery of Biological Drugs

In the last decade, biological drugs have rapidly proliferated and have now become an important therapeutic modality. This is because of their high potency, high specificity and desirable safety profile. The majority of biological drugs are peptide- and protein-based therapeutics with poor oral bioavailability. They are normally administered by parenteral injection (with a very few exceptions). Pulmonary delivery is an attractive non-invasive alternative route of administration for local and systemic delivery of biologics with immense potential to treat various diseases, including diabetes, cystic fibrosis, respiratory viral infection and asthma, etc. The massive surface area and extensive vascularisation in the lungs enable rapid absorption and fast onset of action. Despite the benefits of pulmonary delivery, development of inhalable biological drug is a challenging task. There are various anatomical, physiological and immunological barriers that affect the therapeutic efficacy of inhaled formulations. This review assesses the characteristics of biological drugs and the barriers to pulmonary drug delivery. The main challenges in the formulation and inhalation devices are discussed, together with the possible strategies that can be applied to address these challenges. Current clinical developments in inhaled biological drugs for both local and systemic applications are also discussed to provide an insight for further research.

The Therapeutic Potential of Nanobodies

Today, bio-medical efforts are entering the subcellular level, which is witnessed with the fast-developing fields of nanomedicine, nanodiagnostics and nanotherapy in conjunction with the implementation of nanoparticles for disease prevention, diagnosis, therapy and follow-up. Nanoparticles or nanocontainers offer advantages including high sensitivity, lower toxicity and improved safety—characteristics that are especially valued in the oncology field. Cancer cells develop and proliferate in complex microenvironments leading to heterogeneous diseases, often with a fatal outcome for the patient. Although antibody-based therapy is widely used in the clinical care of patients with solid tumours, its efficiency definitely needs improvement. Limitations of antibodies result mainly from their big size and poor penetration in solid tissues. Nanobodies are a novel and unique class of antigen-binding fragments, derived from naturally occurring heavy-chain-only antibodies present in the serum of camelids. Their superior properties such as small size, high stability, strong antigen-binding affinity, water solubility and natural origin make them suitable for development into next-generation biodrugs. Less than 30 years after the discovery of functional heavy-chain-only antibodies, the nanobody derivatives are already extensively used by the biotechnology research community. Moreover, a number of nanobodies are under clinical investigation for a wide spectrum of human diseases including inflammation, breast cancer, brain tumours, lung diseases and infectious diseases. Recently, caplacizumab, a bivalent nanobody, received approval from the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA) for treatment of patients with thrombotic thrombocytopenic purpura.

Dermal exposure determines the outcome of repeated airway exposure in a long-term chemical-induced asthma-like mouse model

BACKGROUND

Exposure to diisocyanates is an important cause of occupational asthma (OA) in the industrialized world. Since OA occurs after long-term exposure to diisocyanates, we developed a chronic mouse model of chemical-induced asthma where toluene diisocyanate (TDI) was administered at two different exposure sites.

OBJECTIVES

Evaluating the effect of long-term respiratory isocyanate exposure - with or without prior dermal exposure- on sensitization, inflammatory responses and airway hyperreactivity (AHR).

METHODS

On days 1 and 8, BALB/c mice were dermally treated (20 μl/ear) with 0.5% 2,4-toluene diisocyanate TDI or the vehicle acetone olive oil (AOO) (3:2). Starting from day 15, mice received intranasal instillations with 0.1% TDI of vehicle five times in a week, for five successive weeks. One day after the last instillation airway hyperreactivity (AHR) to methacholine was assessed, followed by an evaluation of pulmonary inflammation and structural lung changes. Immune-related parameters were assessed in the lungs (BAL and tissue), blood, cervical- and auricular lymph nodes.

RESULTS

Mice repeatedly intranasally exposed to TDI showed systemic sensitization and a mixed Th1/Th2 type immune response, without the presence of AHR. However, when mice are first dermally sensitized with TDI, followed by repeated intranasal TDI challenges, this results in a pronounced Th2 response and AHR.

CONCLUSION

Dermal exposure to TDI determines airway hyperreactivity after repeated airway exposure to TDI.

In a murine model of acute lung infection, airway administration of a therapeutic antibody confers greater protection than parenteral administration

Due to growing antibiotic resistance, pneumonia caused by Pseudomonas aeruginosa is a major threat to human health and is driving the development of novel anti-infectious agents. Preventively or curatively administered pathogen-specific therapeutic antibodies (Abs) have several advantages, including a low level of toxicity and a unique pharmacological profile. At present, most Abs against respiratory infections are administered parenterally; this may not be optimal for therapeutics that have to reach the lungs to be effective. Although the airways constitute a logical delivery route for biologics designed to treat respiratory diseases, there are few scientific data on the advantages or disadvantages of this route in the context of pneumonia treatment. The objective of the present study was to evaluate the efficacy and fate of an anti-P. aeruginosa Ab targeting pcrV (mAb166) as a function of the administration route during pneumonia. The airway-administered mAb166 displayed a favorable pharmacokinetic profile during the acute phase of the infection, and was associated with greater protection (relative to other delivery routes) of infected animals. Airway administration was associated with lower levels of lung inflammation, greater bacterial clearance, and recruitment of neutrophils in the airways. In conclusion, the present study is the first to have compared the pharmacokinetics and efficacy of an anti-infectious Ab administered by different routes in an animal model of pneumonia. Our findings suggest that local delivery to the airways is associated with a more potent anti-bacterial response (relative to parenteral administration), and thus open up new perspectives for the prevention and treatment of pneumonia with Abs.

Fisetin-treatment alleviates airway inflammation through inhbition of MyD88/NF-κB signaling pathway

Asthma is a common chronic airway inflammation disease and is considered as a major public health problem. Fisetin (3,3′,4′,7-tetrahydroxyflavone) is a naturally occurring flavonoid abundantly found in different vegetables and fruits. Fisetin has been reported to exhibit various positive biological effects, including anti-proliferative, anticancer, anti-oxidative and neuroprotective effects. We evaluated the effects of fisetin on allergic asthma regulation in mice. Mice were first sensi-tized, then airway-challenged with ovalbumin (OVA). Whether fisetin treatment attenuated OVA-induced airway inflammation was examined via inflammation inhibition through MyD88-related NF-κB (p65) signaling pathway. Mice were divided into the control (Con), OVA-induced asthma (Mod), 40 (FL) and 50 (FH) mg/kg fisetin-treated OVA-induced asthma groups. Our results found that OVA-induced airway inflammation in mice caused a significant inflammatory response via the activation of MyD88 and NF-κB signaling pathways, leading to release of pro-inflammatory cytokines. In contrast, fisetin-treated mice after OVA induction inhibited activation of MyD88 and NF-κB signaling pathways, resulting in downregulation of pro-inflammatory cytokine secretion. Further, fisetin significantly ameliorated the airway hyperresponsiveness (AHR) towards methacholine (Mch). In addition, fisetin reduced the number of eosinophil, monocyte, neutrophil and total white blood cell in the bronchoalveolar lavage fluid (BALF) of OVA-induced mice. The serum and BALF samples obtained from the OVA-induced mice with fisetin showed lower levels of pro-inflammatory cytokines. The results of our study illustrated that fisetin may be a new promising candidate to inhibit airway inflammation response induced by OVA.

Tomatidine Attenuates Airway Hyperresponsiveness and Inflammation by Suppressing Th2 Cytokines in a Mouse Model of Asthma

Tomatidine is isolated from the fruits of tomato plants and found to have anti-inflammatory effects in macrophages. In the present study, we investigated whether tomatidine suppresses airway hyperresponsiveness (AHR) and eosinophil infiltration in asthmatic mice. BALB/c mice were sensitized with ovalbumin and treated with tomatidine by intraperitoneal injection. Airway resistance was measured by intubation analysis as an indication of airway responsiveness, and histological studies were performed to evaluate eosinophil infiltration in lung tissue. Tomatidine reduced AHR and decreased eosinophil infiltration in the lungs of asthmatic mice. Tomatidine suppressed Th2 cytokine production in bronchoalveolar lavage fluid. Tomatidine also blocked the expression of inflammatory and Th2 cytokine genes in lung tissue. In vitro, tomatidine inhibited proinflammatory cytokines and CCL11 production in inflammatory BEAS-2B bronchial epithelial cells. These results indicate that tomatidine contributes to the amelioration of AHR and eosinophil infiltration by blocking the inflammatory response and Th2 cell activity in asthmatic mice.

IL-13 is a central mediator of chemical-induced airway hyperreactivity in mice

BACKGROUND

While the importance of the Th2 cytokine IL-13 as a central mediator of airway hyperreactivity (AHR) has been described in allergic protein-induced asthma, this has never been investigated in chemical-induced asthma.

OBJECTIVE

We examined the importance of IL-13 in a mouse model of chemical-induced AHR, using toluene-2,4-diisocyanate (TDI).

METHODS

In a first set-up, wild type (WT) and IL-13 knockout (KO) C57Bl/6 mice were dermally treated on days 1 and 8 with 1% TDI or vehicle (acetone/olive oil) on both ears. On day 15, mice received an intranasal instillation with 0.1% TDI or vehicle. In a second set-up, WT mice sensitized with 1% TDI or vehicle, received i.v. either anti-IL-13 or control antibody prior to the intranasal challenge.

RESULTS

TDI-sensitized and TDI-challenged WT mice showed AHR to methacholine, in contrast to TDI-sensitized and TDI-challenged IL-13 KO mice, which also showed lower levels of total serum IgE. TDI-sensitized and TDI-challenged IL-13 KO mice had lower numbers of T-cells in the auricular lymph nodes. TDI-treated WT mice, receiving anti-IL-13, showed no AHR, in contrast to those receiving control antibody, despite increased levels of IgE. Anti-IL-13 treatment in TDI-treated WT mice resulted in lower levels of serum IL-13, but did not induce changes in T- and B-cell numbers, and in the cytokine production profile.

CONCLUSION AND CLINICAL RELEVANCE

We conclude that IL-13 plays a critical role in the effector phase of chemical-induced, immune-mediated AHR. This implicates that anti-IL-13 treatment could have a beneficial effect in patients with this asthma phenotype.

Therapeutic efficacy of a co-blockade of IL-13 and IL-25 on airway inflammation and remodeling in a mouse model of asthma

Repeated airway inflammation and unremitting remodeling provoke irreversible pulmonary dysfunction and resistance to current drugs in patients with chronic bronchial asthma. Interleukin (IL)-13 and IL-25 play an important role in airway inflammation and remodeling in asthma. We aimed to investigate whether co-inhibiting IL-13 and IL-25 can effectively down-regulate allergen-induced airway inflammation and remodeling in mice. Mice with asthma induced by chronic exposure to ovalbumin (OVA) were given soluble IL-13 receptor α2 (sIL-13R) or soluble IL-25 receptor (sIL-25R) protein alone and in combination to neutralize the bioactivity of IL-13 and IL-25, and relevant airway inflammation and remodeling experiments were performed. We found that the co-blockade of IL-13 and IL-25 with sIL-13R and sIL-25R was more effective than either agent alone at decreasing inflammatory cell infiltration, airway hyperresponsiveness (AhR) and airway remodeling including mucus production, extracellular collagen deposition, smooth muscle cell hyperplasia and angiogenesis in mice exposed to OVA. These results suggest that the combined inhibition of IL-13 and IL-25 may provide a novel therapeutic strategy for asthma, especially for patients who are resistant to current treatments.

Predictors of asthma following severe respiratory syncytial virus (RSV) bronchiolitis in early childhood

BACKGROUND

We sought to identify predictors of asthma development following severe early childhood RSV bronchiolitis. Different definitions of asthma were also compared.

METHODS

This longitudinal, observational study (N = 343) followed patients (<2 years old) from a placebo-controlled trial (N = 979) of montelukast after RSV bronchiolitis to identify clinical, demographic, or biochemical predictors of asthma, atopic disorders, and chronic asthma therapy use at 6 years of age (Clinical Trials Registry Number: NCT01140048). Asthma (primary definition) was based on parental identification of wheeze at 6 AND 12 months before 6 years of age; definitions based on physician diagnosis as well as parental identification of wheeze at 6 OR 12 months (to consider seasonal effect) were also assessed. Post-hoc analyses evaluated agreement among asthma diagnosis criteria.

RESULTS

Prevalence of asthma (primary definition by parental identification), asthma (physician diagnosis), atopic disorders, and chronic asthma therapy use (parental identification) was 6.1%, 22.4%, 36.2%, and 14.5%, respectively. Predictors for asthma (primary definition) included male gender, a relative with asthma, and RAST positive for dog dander; for physician diagnosis of asthma, high severity score for RSV bronchiolitis, high respiratory rate, and asthma diagnosis before enrollment. Predictors of atopic disorders included allergic rhinitis before enrollment, a relative with asthma, and the plasma biomarkers IL-5, IL-16, and IL-18. Predictors of chronic asthma therapy use included asthma diagnosis before enrollment and geographic region (Europe and Africa). Only 42% of patients with asthma (primary definition) also met the asthma definition by physician diagnosis and chronic asthma therapy use.

CONCLUSION

Among children with early RSV bronchiolitis, hereditary factors (i.e., having a relative with asthma) and RSV bronchiolitis severity were predictors of asthma and atopic disorders at 6 years of age. Of interest, there was poor agreement among the asthma definitions evaluated. Pediatr Pulmonol. 2016;51:1382-1392. © 2016 Wiley Periodicals, Inc.

Antibody to FcεRIα Suppresses Immunoglobulin E Binding to High-Affinity Receptor I in Allergic Inflammation

PURPOSE

High-affinity receptor I (FcεRI) on mast cells and basophils plays a key role in the immunoglobulin E (IgE)-mediated type I hypersensitivity mediated by allergen cross-linking of the specific IgE-FcεRI complex. Thus, prevention of IgE binding to FcεRI on these cells is an effective therapy for allergic disease. We have developed a strategy to disrupt IgE binding to FcεRI using an antibody targeting FcεRIα.

MATERIALS AND METHODS

Fab fragment antibodies, which lack the Fc domain, with high affinity and specificity for FcεRIα and effective inhibitory activity against IgE-FcεRI binding were screened. IgE-induced histamine, β-hexosaminidase and Ca²⁺ release in basophils were determined by ELISA. A B6.Cg-Fcer1a(tm1Knt) Tg(FCER1A)1Bhk/J mouse model of passive cutaneous anaphylaxis (PCA) was used to examine the inhibitory effect of NPB311 on allergic skin inflammation.

RESULTS

NPB311 exhibited high affinity to human FcεRIα (KD=4 nM) and inhibited histamine, β-hexosaminidase and Ca²⁺ release in a concentration-dependent manner in hFcεRI-expressing cells. In hFcεRIα-expressing mice, dye leakage was higher in the PCA group than in controls, but decreased after NPB311 treatment. NPB311 could form a complex with FcεRIα and inhibit the release of inflammation mediators.

CONCLUSION

Our approach for producing anti-FcεRIα Fab fragment antibody NPB311 may enable clinical application to a therapeutic pathway in IgE/FcεRI-mediated diseases.

Inhalation of inactivated‑Mycobacterium phlei prevents asthma‑mediated airway hyperresponsiveness and airway eosinophilia in mice by reducing IL‑5 and IL‑13 levels

The present study aimed to investigate whether inhalation of inactivated‑Mycobacterium phlei could prevent airway hyperresponsiveness and airway eosinophilia. A total of 24 male Balb/c mice were randomly divided into three groups: Normal control group (group A), asthma model group (group B) and the intervention group (group C), (8 mice/group). Group A mice were sensitized and with challenged saline and group B with ovalbumin (OVA). Group C mice were administered with aerosol Mycobacterium phlei once daily prior to the allergen challenge. Airway responsiveness in each group was assessed. All the animals were sacrificed and lung tissues, blood samples and bronchoalveolar lavage fluid (BALF) were harvested. Cell fractionation and differential cells were counted in serum and BALF. HE staining and alcian blue/periodic acid Schiff staining were used to measure airway eosinophilic inflammation and mucus production. The levels of the cytokines IL‑5, IL‑13 and IgE were measured in lung and BALF as determined by ELISA and reverse transcription‑quantitative polymerase chain reaction assays. The results indicated that inactivated‑Mycobacterium phlei suppressed the airway hyperresponsiveness and mitigated airway eosinophilia induced by a methacholine challenge, and significantly reduced the levels of cytokines IL‑5 and IL‑13 in lung tissue and IgE level in BALF when compared with the OVA‑sensitized mice. In conclusion, inhalation of inactivated‑Mycobacterium phlei could reduce OVA‑induced airway hyperresponsiveness and may be a potential alternative therapy for allergic airway diseases.

Strategies targeting the IL-4/IL-13 axes in disease

IL-4 and IL-13 are pleiotropic Th2 cytokines produced by a wide variety of different cell types and responsible for a broad range of biology and functions. Physiologically, Th2 cytokines are known to mediate host defense against parasites but they can also trigger disease if their activities are dysregulated. In this review we discuss the rationale for targeting the IL-4/IL-13 axes in asthma, atopic dermatitis, allergic rhinitis, COPD, cancer, inflammatory bowel disease, autoimmune disease and fibrotic disease as well as evaluating the associated clinical data derived from blocking IL-4, IL-13 or IL-4 and IL-13 together.

Intranasal exposure to monoclonal antibody Fab fragments to Japanese cedar pollen Cry j1 suppresses Japanese cedar pollen-induced allergic rhinitis

BACKGROUND AND PURPOSE

Fab fragments (Fabs) of antibodies have the ability to bind to specific allergens but lack the Fc portion that exerts effector functions via binding to receptors including FcεR1 on mast cells. In the present study, we investigated whether intranasal administration of the effector function-lacking Fabs of a monoclonal antibody IgG1 (mAb, P1-8) to the major allergen Cry j1 of Japanese cedar pollen (JCP) suppressed JCP-induced allergic rhinitis in mice.

EXPERIMENTAL APPROACH

Balb/c mice sensitized with JCP on days 0 and 14 were challenged intranasally with the pollen on days 28, 29, 30 and 35. Fabs prepared by the digestion of P1-8 with papain were also administered intranasally 15 min before each JCP challenge.

KEY RESULTS

Intranasal administration of P1-8 Fabs was followed by marked suppression of sneezing and nasal rubbing in mice with JCP-induced allergic rhinitis. The suppression of these allergic symptoms by P1-8 Fabs was associated with decreases in mast cells and eosinophils and decreased hyperplasia of goblet cells in the nasal mucosa.

CONCLUSIONS AND IMPLICATIONS

These results demonstrated that intranasal exposure to P1-8 Fabs was effective in suppressing JCP-induced allergic rhinitis in mice, suggesting that allergen-specific mAb Fabs might be used as a tool to regulate allergic pollinosis.

Forkhead box protein A2 and T helper type 2-mediated pulmonary inflammation

The transcription factor forkhead box protein A2 (FOXA2, also known as hepatocyte nuclear factor 3β or transcription factor 3β), has been found to play pivotal roles in multiple phases of mammalian life, from the early development to the organofaction, and subsequently in homeostasis and metabolism in the adult. In the embryonic development period, FOXA2 is require d for the formation of the primitive node and notochord, and its absence results in embryonic lethality. Moreover, FOXA2 plays an important role not only in lung development, but also in T helper type 2 (Th2)-mediated pulmonary inflammation and goblet cell hyperplasia. In this article, the role of FOXA2 in lung development and Th2-mediated pulmonary inflammation, as well as in goblet cell hyperplasia, is reviewed. FOXA2 deletion in airway epithelium results into Th2-mediated pulmonary inflammation and goblet cell hyperplasia in developing lung. Leukotriene pathway and signal transducers and activators of transcription 6 pathway may mediate this inflammation through recruitment and activation of denditric cell during lung developments. FOXA2 is a potential treatment target for lung diseases with Th2 inflammation and goblet cell hyperplasia, such as asthma and chronic obstructive pulmonary disease.

Glucagon Like Peptide-1 (GLP-1) Modulates OVA-Induced Airway Inflammation and Mucus Secretion Involving a Protein Kinase A (PKA)-Dependent Nuclear Factor-κB (NF-κB) Signaling Pathway in Mice

Asthma is a common chronic pulmonary inflammatory disease, featured with mucus hyper-secretion in the airway. Recent studies found that glucagon like peptide-1 (GLP-1) analogs, including liraglutide and exenatide, possessed a potent anti-inflammatory property through a protein kinase A (PKA)-dependent signaling pathway. Therefore, the aim of current study was to investigate the value of GLP-1 analog therapy liraglutide in airway inflammation and mucus secretion in a murine model of ovalbumin (OVA)-induced asthma, and its underlying molecular mechanism. In our study, BALB/c mice were sensitized and challenged by OVA to induce chronic asthma. Pathological alterations, the number of cells and the content of inflammatory mediators in bronchoalveolar lavage fluid (BALF), and mucus secretion were observed and measured. In addition, the mRNA and protein expression of E-selectin and MUC5AC were analyzed by qPCR and Western blotting. Then, the phosphorylation of PKA and nuclear factor-κB (NF-κB) p65 were also measured by Western blotting. Further, NF-κB p65 DNA binding activity was detected by ELISA. OVA-induced airway inflammation, airway mucus hyper-secretion, the up-regulation of E-selectin and MUC5AC were remarkably inhibited by GLP-1 in mice (all p < 0.01). Then, we also found that OVA-reduced phosphorylation of PKA, and OVA-enhanced NF-κB p65 activation and NF-κB p65 DNA binding activity were markedly improved by GLP-1 (all p < 0.01). Furthermore, our data also figured out that these effects of GLP-1 were largely abrogated by the PKA inhibitor H-89 (all p < 0.01). Taken together, our results suggest that OVA-induced asthma were potently ameliorated by GLP-1 possibly through a PKA-dependent inactivation of NF-κB in mice, indicating that GLP-1 analogs may be considered an effective and safe drug for the potential treatment of asthma in the future.

Biologic comparison of inhaled insulin formulations: Exubera™ and novel spray-dried engineered particles of dextran-10

Inhaled peptides and proteins have promise for respiratory and systemic disease treatment. Engineered spray-dried powder formulations have been shown to stabilize peptides and proteins and optimize aerosol properties for pulmonary delivery. The current study was undertaken to investigate the in vitro and in vivo inhalation performance of a model spray-dried powder of insulin and dextran 10 in comparison to Exubera™. Dextrans are a class of glucans that are generally recognized as safe with optimum glass transition temperatures well suited for spray drying. A 70% insulin particle loading was prepared by formulating with 30% (w/v) dextran 10. Physical characterization revealed a "raisin like" particle. Both formulations were generated to produce a similar bimodal particle size distribution of less than 3.5 μm MMAD. Four female Beagle dogs were exposed to each powder in a crossover design. Similar presented and inhaled doses were achieved with each powder. Euglycemia was achieved in each dog prior and subsequent to dosing and blood samples were drawn out to 245 min post-exposure. Pharmacokinetic analyses of post-dose insulin levels were similar for both powders. Respective dextran 10-insulin and Exubera exposures were similar producing near identical area under the curve (AUC), 7,728 ± 1,516 and 6,237 ± 2,621; concentration maximums (C max), 126 and 121 (μU/mL), and concentration-time maximums, 20 and 14 min, respectively. These results suggest that dextran-10 and other dextrans may provide a novel path for formulating peptides and proteins for pulmonary delivery.

Aligning mouse models of asthma to human endotypes of disease

Substantial gains in understanding the pathophysiologic mechanisms underlying asthma have been made using preclinical mouse models. However, because asthma is a complex, heterogeneous syndrome that is rarely due to a single allergen and that often presents in the absence of atopy, few of the promising therapeutics that demonstrated effectiveness in mouse models have translated into new treatments for patients. This has resulted in an urgent need to characterize T helper (Th) 2-low, non-eosinophilic subsets of asthma, to study models that are resistant to conventional treatments such as corticosteroids and to develop therapies targeting patients with severe disease. Classifying asthma based on underlying pathophysiologic mechanisms, known as endotyping, offers a stratified approach for the development of new therapies for asthma. In preclinical research, new models of asthma are being utilized that more closely resemble the clinical features of different asthma endotypes, including the presence of interleukin-17 and a Th17 response, a biomarker of severe disease. These models utilize more physiologically relevant sensitizing agents, exacerbating factors and allergens, as well as incorporate time points that better reflect the natural history and chronicity of clinical asthma. Importantly, some models better represent non-classical asthma endotypes that facilitate the study of non-Th2-driven pathology and resemble the complex nature of clinical asthma, including corticosteroid resistance. Placing mouse asthma models into the context of human asthma endotypes will afford a more relevant approach to the understanding of pathophysiological mechanisms of disease that will afford the development of new therapies for those asthmatics that remain difficult to treat.

Intratracheal exposure to Fab fragments of an allergen-specific monoclonal antibody regulates asthmatic responses in mice

Fab fragments (Fabs) maintain the ability to bind to specific antigens but lack effector functions due to the absence of the Fc portion. In the present study, we tested whether Fabs of an allergen-specific monoclonal antibody (mAb) were able to regulate asthmatic responses in mice. Asthmatic responses were induced in BALB/c mice by passive sensitization with anti-ovalbumin (OVA) polyclonal antibodies (pAbs) (day 0) and by active sensitization with OVA (days 0 and 14), followed by intratracheal (i.t.) challenge with OVA on day 1 and days 28, 29, 30 and 35. Fabs prepared by the digestion of an anti-OVA IgG1 (O1-10) mAb with papain were i.t. administered only once 30 min before antigenic challenge on day 1 or day 35. The results showed that i.t. administration of O1-10 Fabs with OVA markedly suppressed the early and/or late phases of asthmatic responses caused by passive and active sensitization. Similar results were obtained when Fabs of anti-OVA IgG2b mAb (O2B-3) were i.t. administered. In contrast, neither i.t. injection of intact 01-10/O2B-3 nor systemic injection of O1-10 Fabs suppressed the asthmatic responses. In vitro studies revealed that the capture of OVA by O1-10 Fabs prevented the subsequent binding of intact anti-OVA pAbs to the captured OVA. These results suggest that asthmatic responses may be down-regulated by the i.t. exposure to Fabs of an allergen-specific mAb via a mechanism involving the capture of allergen by Fabs in the respiratory tract before the interaction of intact antibody and allergen essential for the induction of asthmatic responses.

TLR3 activation augments matrix metalloproteinase production through reactive nitrogen species generation in human lung fibroblasts

Viral infection often triggers asthma exacerbation and contributes to airway remodeling. Cell signaling in viral infection is mainly mediated through TLR3. Many mediators are involved in airway remodeling, but matrix metalloproteinases (MMPs) are key players in this process in asthma. However, the role of TLR3 activation in production of MMPs is unknown. In this study, we examined the effects of polyinosinic-polycytidylic acid [poly(I:C)], a ligand for TLR3, on production of MMPs in human lung fibroblasts, with a focus on nitrosative stress in TLR3 modulation of MMP production. After lung fibroblasts were treated with poly(I:C), production of MMP-1, -2, and -9 and inducible NO synthase (iNOS) was assessed. The roles of NF-κB and IFN regulatory factor-3 (IRF-3) in the poly(I:C)-mediated production of MMPs and the responsiveness to poly(I:C) of normal lung fibroblasts and asthmatic lung fibroblasts were also investigated. Poly(I:C) augmented production of MMPs and iNOS in fibroblasts, and an iNOS inhibitor diminished this production of MMPs. Poly(I:C) stimulated translocation of NF-κB and IRF-3 into the nucleus in fibroblasts and inhibition of NF-κB or IRF-3 abrogated the poly(I:C)-induced increase in both iNOS expression and release of MMPs. Poly(I:C)-induced production of iNOS and MMPs was greater in asthmatic fibroblasts than in normal fibroblasts. We conclude that viral infection may induce nitrosative stress and subsequent MMP production via NF-κB- and IRF-3-dependent pathways, thus potentiating viral-induced airway remodeling in asthmatic airways.

A comparative study on the physicochemical and biological stability of IgG1 and monoclonal antibodies during spray drying process

Background

The main concern in formulation of antibodies is the intrinsic instability of these labile compounds. To evaluate the physicochemical stability of antibody in dry powder formulations, physical stability of IgG₁ and a monoclonal antibody (trastuzumab) during the spray drying process was studied in a parallel study and the efficacy of some sugar based excipients in protection of antibodies was studied.

Results

The SDS-PAGE analysis showed no fragmentation of antibodies after spray drying in all formulations. The secondary structure of antibodies contained 40.13 to 70.19% of β structure in dry state. Also, CD spectroscopy showed the similar secondary structure for trastuzumab after reconstitution in water. ELISA analysis and cell culture studies were conducted in order to evaluate bioactivity of monoclonal antibody. Formulations containing combination of excipients provided maximum tendency of trastuzumab to attach to the ELISA antigen (86.46% ± 2.3) and maximum bioactivity when incubated with SKBr₃ cell line (the cell viability was decreased to 65.99% ± 4.6). Incubation of formulations with L929 cell line proved the biocompatibility of the excipients and non-toxic composition of formulations.

Conclusion

The IgG₁ and trastuzumab demonstrated similar behavior in spray drying process. The combination of excipients containing trahalose, hydroxypropyl beta cyclodextrin and beta cyclodextrin with proper ratio improved the physical and chemical stability of both IgG₁ and monoclonal antibody.

Optimizing the primary particle size distributions of pressurized metered dose inhalers by using inkjet spray drying for targeting desired regions of the lungs

Conventional suspension pressurized metered dose inhalers (pMDIs) suffer not only from delivering small amounts of a drug to the lungs, but also the inhaled dose scatters all over the lung regions. This results in much less of the desired dose being delivered to regions of the lungs. This study aimed to improve the aerosol performance of suspension pMDIs by producing primary particles with narrow size distributions. Inkjet spray drying was used to produce respirable particles of salbutamol sulfate. The Next Generation Impactor (NGI) was used to determine the aerosol particle size distribution and fine particle fraction (FPF). Furthermore, oropharyngeal models were used with the NGI to compare the aerosol performances of a pMDI with monodisperse primary particles and a conventional pMDI. Monodisperse primary particles in pMDIs showed significantly narrower aerosol particle size distributions than pMDIs containing polydisperse primary particles. Monodisperse pMDIs showed aerosol deposition on a single stage of the NGI as high as 41.75 ± 5.76%, while this was 29.37 ± 6.79% for a polydisperse pMDI. Narrow size distribution was crucial to achieve a high FPF (49.31 ± 8.16%) for primary particles greater than 2 µm. Only small polydisperse primary particles with sizes such as 0.65 ± 0.28 µm achieved a high FPF with (68.94 ± 6.22%) or without (53.95 ± 4.59%) a spacer. Oropharyngeal models also indicated a narrower aerosol particle size distribution for a pMDI containing monodisperse primary particles compared to a conventional pMDI. It is concluded that, pMDIs formulated with monodisperse primary particles show higher FPFs that may target desired regions of the lungs more effectively than polydisperse pMDIs.

IL-13 and STAT6 signaling involve in low dose lipopolysaccharide induced murine model of asthma

Background

We reported that level of lipopolysaccharide (LPS) exposure determined the type of airway inflammation in a murine model of asthma.

Objective

The purpose of this study is to evaluated the role of IL-13 in low dose LPS induced murine model of asthma using IL-13 and signal transducer and activator of transcription 6 (STAT6) deficient mice.

Methods

Mice were sensitized with an intranasal application of LPS-depleted ovalbumin (OA) and different doses of LPS (0.1 and 10 µg), and then challenged intranasally with OA alone. The phenotype changes between wild type (WT) and IL-13^-/- mice and between WT and STAT6^-/- mice were evaluated.

Results

We confirmed again that low and high dose LPS resulted in different phenotypes of murine asthma. In the present study, we observed that phenotypes of murine asthma induced by low dose LPS were abolished in the homozygous null mutation of the IL-13 and STAT6 gene. However, those changes were not shown in mice sensitized OA plus high dose LPS.

Conclusion

IL-13 plays an important role in low dose LPS induced murine model of asthma. Our results provided a new insight in understanding of the potential role of IL-13 in innate immunity in human allergic asthma.