Sorting out the cytokines of asthma

Anthriscus sylvestris-Noxious Weed or Sustainable Source of Bioactive Lignans?

Anthriscus sylvestris (L.) Hoffm. (Apiaceae), commonly known as wild chervil, has gained scientific interest owing to its diverse phytochemical profile and potential therapeutic applications. The plant, despite being categorized as a noxious weed, is traditionally used in treating various conditions like headaches, dressing wounds, and as a tonic, antitussive, antipyretic, analgesic, and diuretic. Its pharmacological importance stems from containing diverse bioactive lignans, especially aryltetralins and dibenzylbutyrolactones. One of the main compounds of A. sylvestris, deoxypodophyllotoxin, among its wide-ranging effects, including antitumor, antiproliferative, antiplatelet aggregation, antiviral, anti-inflammatory, and insecticidal properties, serves as a pivotal precursor to epipodophyllotoxin, crucial in the semisynthesis of cytostatic agents like etoposide and teniposide. The main starting compound for these anticancer medicines was podophyllotoxin, intensively isolated from Sinopodophyllum hexandrum, now listed as an endangered species due to overexploitation. Since new species are being investigated as potential sources, A. sylvestris emerges as a highly promising candidate owing to its abundant lignan content. This review summarizes the current knowledge on A. sylvestris, investigating its biological and morphological characteristics, and pharmacological properties. Emphasizing the biological activities and structure-activity relationship, this review underscores its therapeutic potential, thus encouraging further exploration and utilization of this valuable plant resource.

Immune Dysregulation, Inflammation in Characterizing Women with Vulvodynia, Depression, and Both

Background: Depression and vulvodynia are often comorbid. The onset of depression and vulvodynia may be immune and/or stress/environmentally induced. We explored whether vulvodynia, depression, or both occur in response to a Th1-mediated versus Th2-mediated immune response. Materials and Methods: We analyzed data from a case-control study of clinically confirmed vulvodynia and history of depression determined through structured clinical interviews. Immune dysregulation and inflammation were categorized based on the following self-reported conditions: rheumatoid arthritis, Sjogren's disease, scleroderma, systemic lupus erythematosus, inflammatory bowel disease, fibromyalgia, osteoarthritis, polycystic ovarian syndrome, diabetes mellitus, uterine fibroids, asthma, atopic dermatitis, and allergic rhinitis. Logistic regression analyses were adjusted for marital status, body mass index, age, and pack years. Results: Women with systemic immune dysregulation had higher odds of depression (adjusted odds ratio [aOR] = 1.61, confidence interval [95% CI]: 0.65-3.98), vulvodynia (aOR = 2.45, 95% CI: 1.00-5.96), and comorbid depression and vulvodynia (aOR = 4.93, 95% CI: 2.19-11.10) versus neither condition. Women reporting local immune dysregulation had similar odds of depression (aOR = 1.89, 95% CI: 0.99-3.59), vulvodynia (aOR = 2.12, 95% CI: 1.08-4.18), and comorbid depression and vulvodynia (aOR = 1.96, 95% CI: 0.98-3.90). Women with Th2 inflammation had similar odds of depression (aOR = 2.23, 95% CI: 1.05-4.77) and vulvodynia (aOR = 2.56, 95% CI: 1.20-5.49). Women with Th1 or Th2 inflammation had similar odds of comorbid depression and vulvodynia (aOR = 3.03, 95% CI: 1.48-6.19; aOR = 3.14, 95% CI: 1.49-6.60, respectively). Conclusions: Our results suggest that an imbalance of cytokines, indicated by the presence of one or more immune-related health conditions, is associated with an increased risk of vulvodynia and/or depression.

Detection of Lectin Protein Allergen of Kidney Beans (Phaseolus vulgaris L.) and Desensitization Food Processing Technology

With the increase of food allergy events related to not properly cooked kidney beans (Phaseolus vulgaris L.), more and more researchers are paying attention to the sensitization potential of lectin, one of the major storage and defensive proteins with the specific carbohydrate-binding activity. The immunoglobulin E (IgE), non-IgE, and mixed allergic reactions induced by the lectins were inducted in the current paper, and the detection methods of kidney bean lectin, including the purification strategies, hemagglutination activity, specific polysaccharide or glycoprotein interactions, antibody combinations, mass spectrometry methods, and allergomics strategies, were summarized, while various food processing aspects, such as the physical thermal processing, physical non-thermal processing, chemical modifications, and biological treatments, were reviewed in the potential of sensitization reduction. It might be the first comprehensive review on lectin allergen detection from kidney bean and the desensitization strategy in food processing and will provide a basis for food safety control.

Combination of Sarsasapogenin and Fluticasone attenuates ovalbumin-induced airway inflammation in a mouse asthma model

Objective: Asthma is a very common airway inflammatory disease for which the existing drug therapy options are insufficient. In this study, we explored the mechanisms underlying the anti-inflammatory potential of Sarsapogenin (SG) and its combination with Fluticasone (FC) in ovalbumin (OVA)-induced allergic asthma in mice.Methods: In a standard experimental model, asthma in mice was sensitized and challenged by OVA. The mice were treated with SG and SG + FC during OVA challenge. At the completion, lung weight, inflammatory cell count in bronchoalveolar lavage fluid (BALF), serum cytokines levels, immunoglobulin E (IgE) levels, lung nitrate/nitrite (NO) levels, and lung tissue oxidative stress biomarkers were determined. Histopathological evaluation of the lung tissue was also performed.Key findings: Treatment of mice with SG and SG + FC combination intensely diminished the trafficking of total and differential inflammatory cells count into BALF. SG and SG + FC administration significantly reduced the production of inflammatory cytokines, serum IgE levels and restoration of antioxidant stress markers. Histopathological analysis of lung samples effectually weakened bronchial inflammation and mucus production in the lung with a significant reduction in inflammation and mucus score.Conclusion: Our study results suggested that SG and SG + FC effectively reduced allergic airway inflammation via inhibiting pro-inflammatory cytokines, NO expressions and oxidative stress parameters. So, it could be used as a therapeutic potential agent for the treatment of asthma by decreasing its dose in combination with FC to avoid the chronic adverse effects of FC.

Anti-inflammatory potential of hecogenin on atopic dermatitis and airway hyper-responsiveness by regulation of pro-inflammatory cytokines

Objective: Hecogenin is a sapogenin found in Agave sisalana species that is used extensively for the treatment of anti-inflammatory, antifungal, hypotensive, anti-nociceptive activity and cancer. We have studied the anti-inflammatory effect of Hecogenin and its combination with Fluticasone on atopic dermatitis and airway hyper-responsiveness in Balb/c mice. Material and methods: Dermatitis was induced by repeated application of 2, 4-dinitrofluorobenzene in Balb/c mice. After a topical application of Hecogenin, Fluticasone and their combination on the skin lesions, the ear thickness, ear weight and erythema score were evaluated. Asthma was induced by sensitization and challenge of ovalbumin in Balb/c mice. Results: The topical application of Hecogenin and its combination with Fluticasone in mice effectively suppressed the ear swelling and weight. As well as the levels of pro-inflammatory cytokines were decreased by Hecogenin and its combination in-vivo. Whereas, intra-nasal administration of Hecogenin and its combination in ovalbumin induced airway hyper-responsiveness reveals a significant decrement in total cell count, differential cell count and cytokines levels. Similar observations were obtained for myeloperoxidase level in ear and lung tissue. The results were supported by histological studies of ear and lung tissue. Conclusion: These data indicate that Hecogenin has been proved as a potential therapy for allergic skin diseases and bronchial asthma treatments in combination with Fluticasone by reducing its dose from 50 to 25 μg/mice in combination to circumvent the long term side effects of Fluticasone. The beneficial effect of Hecogenin may be related to the diminution of TNF-α and IL-12 cytokines production in Balb/c mice.

Preformulation and Evaluation of Tofacitinib as a Therapeutic Treatment for Asthma

Preformulation studies on tofacitinib citrate, a small molecule JAK3 specific inhibitor, have not been previously reported in literature. We therefore conducted several preformulation studies on tofacitinib citrate, and its free base, to better understand factors that affect its solubility, stability, and solid-state characteristics. Further, the results of the preformulation studies helped facilitate the development of a nebulized formulation of tofacitinib citrate for inhalational delivery to house dust mite allergen-challenged, BALB/c mice as a potential treatment for eosinophilic asthma. The preformulation results indicated tofacitinib having a basic pKa of 5.2, with its stability dependent on pH, ionic strength, and temperature. Degradation of tofacitinib follows apparent first-order kinetics. In order to maximize stability of the drug, ionic strength and temperature should be minimized, with an optimal range pH between 2.0 and 5.0. Additionally, our findings demonstrate that tofacitinib citrate can successfully be nebulized at a suitable droplet size for inhalation (1.2 ± 0.2 μm MMAD) through a nose-only chamber. Animals dosed with tofacitinib citrate demonstrated marked reductions in BAL eosinophils and total protein concentrations following HDM challenge. These data suggest that tofacitinib citrate represents the potential to be an effective therapy for eosinophilic asthma.

Modeling TH 2 responses and airway inflammation to understand fundamental mechanisms regulating the pathogenesis of asthma

In this review, we highlight experiments conducted in our laboratories that have elucidated functional roles for CD4⁺ T-helper type-2 lymphocytes (T_H 2 cells), their associated cytokines, and eosinophils in the regulation of hallmark features of allergic asthma. Notably, we consider the complexity of type-2 responses and studies that have explored integrated signaling among classical T_H 2 cytokines (IL-4, IL-5, and IL-13), which together with CCL11 (eotaxin-1) regulate critical aspects of eosinophil recruitment, allergic inflammation, and airway hyper-responsiveness (AHR). Among our most important findings, we have provided evidence that the initiation of T_H 2 responses is regulated by airway epithelial cell-derived factors, including TRAIL and MID1, which promote T_H 2 cell development via STAT6-dependent pathways. Further, we highlight studies demonstrating that microRNAs are key regulators of allergic inflammation and potential targets for anti-inflammatory therapy. On the background of T_H 2 inflammation, we have demonstrated that innate immune cells (notably, airway macrophages) play essential roles in the generation of steroid-resistant inflammation and AHR secondary to allergen- and pathogen-induced exacerbations. Our work clearly indicates that understanding the diversity and spatiotemporal role of the inflammatory response and its interactions with resident airway cells is critical to advancing knowledge on asthma pathogenesis and the development of new therapeutic approaches.

Interleukin-33 and its Receptor in Pulmonary Inflammatory Diseases

Interleukin-33 (IL-33) is a member of the IL-1 cytokine family. It modulates immune responses and biological functions through binding to its membrane receptor, ST2L. ST2L is a member of the Toll-like/IL-1 (TIR)-receptor superfamily, and its isoform, soluble ST2 (sST2), functions as an inhibitor of the IL-33/ST2L pathway. Levels of IL-33 and sST2 in serum and bronchoalveolar lavage fluid (BAL) are known biomarkers for a variety of disorders such as heart failure, non-small-cell lung cancer, and pulmonary inflammatory diseases. IL-33 also exists in the nuclei, and nuclear IL-33 seems to regulate cytokine gene expression. In this review, we focus on the role of IL-33/ST2 in the pathogenesis of pulmonary inflammatory diseases including asthma, chronic obstructive pulmonary disease (COPD), and lung injury.

Race is associated with differences in airway inflammation in patients with asthma

BACKGROUND

African American subjects have a greater burden from asthma compared with white subjects. Whether the pattern of airway inflammation differs between African American and white subjects is unclear.

OBJECTIVE

We sought to compare sputum airway inflammatory phenotypes of African American and white subjects treated or not with inhaled corticosteroids (ICSs; ICS+ and ICS-, respectively).

METHODS

We performed a secondary analysis of self-identified African American and white subjects with asthma enrolled in clinical trials conducted by the National Heart, Lung, and Blood Institute-sponsored Asthma Clinical Research Network and AsthmaNet. Demographics, clinical characteristics, and sputum cytology after sputum induction were examined. We used a sputum eosinophil 2% cut point to define subjects with either an eosinophilic (≥2%) or noneosinophilic (<2%) inflammatory phenotype.

RESULTS

Among 1018 participants, African American subjects (n = 264) had a lower FEV1 percent predicted (80% vs 85%, P < .01), greater total IgE levels (197 vs 120 IU/mL, P < .01), and a greater proportion with uncontrolled asthma (43% vs 28%, P < .01) compared with white subjects (n = 754). There were 922 subjects in the ICS+ group (248 African American and 674 white subjects) and 298 subjects in the ICS- group (49 African American and 249 white subjects). Eosinophilic airway inflammation was not significantly different between African American and white subjects in either group (percentage with eosinophilic phenotype: ICS+ group: 19% vs 16%, P = .28; ICS- group: 39% vs 35%, P = .65; respectively). However, when adjusted for confounding factors, African American subjects were more likely to exhibit eosinophilic airway inflammation than white subjects in the ICS+ group (odds ratio, 1.58; 95% CI, 1.01-2.48; P = .046) but not in the ICS- group (P = .984).

CONCLUSION

African American subjects exhibit greater eosinophilic airway inflammation, which might explain the greater asthma burden in this population.

Local Effects on Airway Inflammation and Systemic Uptake of 5 nm PEGylated and Citrated Gold Nanoparticles in Asthmatic Mice

Nanotechnology is showing promise in many medical applications such as drug delivery and hyperthermia. Nanoparticles administered to the respiratory tract cause local reactions and cross the blood-air barrier, thereby providing a means for easy systemic administration but also a potential source of toxicity. Little is known about how these effects are influenced by preexisting airway diseases such as asthma. Here, BALB/c mice are treated according to the ovalbumin (OVA) asthma protocol to promote allergic airway inflammation. Dispersions of polyethylene-glycol-coated (PEGylated) and citrate/tannic-acid-coated (citrated) 5 nm gold nanoparticles are applied intranasally to asthma and control groups, and (i) airway resistance and (ii) local tissue effects are measured as primary endpoints. Further, nanoparticle uptake into extrapulmonary organs is quantified by inductively coupled plasma mass spectrometry. The asthmatic precondition increases nanoparticle uptake. Moreover, systemic uptake is higher for PEGylated gold nanoparticles compared to citrated nanoparticles. Nanoparticles inhibit both inflammatory infiltrates and airway hyperreactivity, especially citrated gold nanoparticles. Although the antiinflammatory effects of gold nanoparticles might be of therapeutic benefit, systemic uptake and consequent adverse effects must be considered when designing and testing nanoparticle-based asthma therapies.

Systemic and mucosal pre-administration of recombinant Helicobacter pylori neutrophil-activating protein prevents ovalbumin-induced allergic asthma in mice

PURPOSE

Previous epidemiologic studies have demonstrated an inverse association between Helicobacter pylori infection and the frequency of allergic asthma. The neutrophil-activating protein (NAP) of H. pylori has been identified as a modulator possessing anti-Th2 inflammation activity. Here, we sought to determine whether systemic or mucosal pre-administration of recombinant H. pylori NAP (rNAP) could prevent ovalbumin (OVA)-induced allergic asthma in mice.

METHODS

Mice were exposed to purified rNAP through intraperitoneal injection or inhalation and then sensitized with OVA. Following a challenge with aerosolized OVA, the bronchoalveolar lavage fluid (BALF) cell count, lung tissue histology, BALF cytokines and serum IgE were evaluated.

RESULTS

Both intraperitoneal injection and inhalation of rNAP prior to OVA sensitization significantly reduced eosinophil accumulation and inflammatory infiltration in lung tissue in OVA-induced asthma mice; eosinophils were reduced in the BALF of rNAP-treated mice. In addition, IL-4 and IL-13 levels were lower (P < 0.01), IL-10 and IFN-γ levels were higher (P < 0.01) and IgE serum levels were lower (P < 0.01) in the treated groups compared to the control group.

CONCLUSIONS

Systemic and mucosal pre-administration of rNAP could suppress the development of OVA-induced asthma in mice; rNAP may be utilized as part of novel strategies for the prevention or treatment of allergic diseases.

Allergy Vaccines Using a Mycobacterium-Secreted Antigen, Ag85B, and an IL-4 Antagonist

In recent decades, the prevalence of allergic diseases, including bronchial asthma, airway hypersensitivity, hay fever, and atopic dermatitis, has been increasing in the industrialized world, and effective treatments probably require manipulating the inflammatory response to pathogenic allergens. T helper (Th) 2 cells are thought to play a crucial role in the initiation, progression, and persistence of allergic responses in association with production of interleukin (IL)-4, IL-5, and IL-13. Therefore, a strategy of a shift from Th2- to Th1-type immune response may be valuable in the prophylaxis and management of allergic diseases. It is also necessary to develop prophylactic and therapeutic treatment that induces homeostatic functions in the multifaceted allergic environment, because various factors including innate and adaptive immunity, mucosal immune response, and functional and structural maintenance of local tissue might be involved in the pathogenesis of allergic disorders. We review herein recent findings related to the curative effect for mouse models of asthma and atopic dermatitis using DNA-, virus-, and protein-based vaccines of a Mycobacterium secretion antigen, Ag85B, and a plasmid encoding cDNA of antagonistic IL-4 mutant.

Exposure to Aedes aegypti Bites Induces a Mixed-Type Allergic Response following Salivary Antigens Challenge in Mice

Classical studies have shown that Aedes aegypti salivary secretion is responsible for the sensitization to mosquito bites and many of the components present in saliva are immunogenic and capable of inducing an intense immune response. Therefore, we have characterized a murine model of adjuvant-free systemic allergy induced by natural exposure to mosquito bites. BALB/c mice were sensitized by exposure to A. aegypti mosquito bites and intranasally challenged with phosphate-buffered saline only or the mosquito’s salivary gland extract (SGE). Blood, bronchoalveolar lavage (BAL) and lung were collected and evaluated for cellularity, histopathological analyses, cytokines and antibody determination. Respiratory pattern was analyzed by Penh measurements and tracheal segments were obtained to study in vitro reactivity to methacholine. BAL recovered from sensitized mice following challenge with SGE showed an increased number of eosinophils and Th2 cytokines such as IL-4, IL-5 and IL-13. Peribronchoalveolar eosinophil infiltration, mucus and collagen were also observed in lung parenchyma of sensitized mice, suggesting the development of a typical Th2 response. However, the antibody profile in serum of these mice evidenced a mixed-type response with presence of both, IgG1/IgE (Th2-related) and IgG2a (Th1-related) isotypes. In addition, changes in breathing pattern and tracheal reactivity to methacholine were not found. Taken together, our results show that A. aegypti bites trigger an atypical allergic reaction, with some classical cellular and soluble Th2 components in the lung, but also systemic Th1 and Th2 antibody isotypes and no change in either the respiratory pattern or the trachea responsiveness to agonist.

Elements Involved In Promoting Eosinophilic Gastrointestinal Disorders

Eosinophilic gastrointestinal disorders (EGID) are food allergen-induced allergic gastrointestinal disorders, characterized by accumulation of highly induced eosinophils in different segments of gastrointestinal tract along with eosinophil microabssess and extracellular eosinophilic granules in the epithelial layer. EGID are both IgE- and cell-mediated group of diseases that include eosinophilic esophagitis (EoE), eosinophilic gastritis (EG), eosinophilic gastroenteritis (EGE) and eosinophilic colitis (EC). Despite the increased incidences and considerable progress made in understanding EGID pathogenesis. The mechanism is still not well understood. It has been shown that IL-4, IL-5, IL-13, IL-15, IL-18, eotaxin-1, eotaxin-2 and eotaxin-3 play a critical role in EGID pathogenesis. Currently, the only criterion for diagnosing EoE, EGE and EC are repetitive endoscopic and histopathological evaluation of biopsies along with other clinical characteristics/manifestations. Antigen elimination and corticosteroid therapies are the most effective therapies currently in practice for the treatment of EGID. The cytokines (anti-IL-5 and anti-IL-13) therapy trials were not very successful in case of EoE. Most recently, a clinical trial using anti-IL-13 reported only 60% reduced esophageal eosinophilia without achieving primary endpoint. This clinical finding is not surprising and is in accordance with our earlier report indicating that IL-13 is not critical in the initiation of EoE. Notably, EGID still has no reliable noninvasive diagnostic biomarkers. Hence, there is a great necessity to identify novel noninvasive diagnostic biomarkers that can easily diagnose EGID and provide an effective therapy. Now, the attention is required to target cell types like iNKT cells that produce eosinophil active cytokines and is found induced in the pathogenesis of both experimental and human EoE. iNKT cell neutralization is shown to protect allergen-induced EoE in experimental model. In this review, we have discussed the key elements that are critical in the disease initiation, progression, pathogenesis and important for future diagnostic and therapeutic interventions for EGID.

IgE responses in mouse and man and the persistence of IgE memory

Rapid and robust recall or 'memory' responses are an essential feature of adaptive immunity. They constitute a defense against reinfection by pathogens, yet arguably do more harm than good in allergic disease. Immunoglobulin (Ig)E antibodies mediate the allergic reaction characterized by immediate hypersensitivity, a manifestation of IgE memory. The origin of IgE memory remains obscure, mainly due to the low proportion of IgE-expressing B cells in the total B cell population. The recent development of ultrasensitive methods for tracking these cells in vivo has overcome this obstacle, and their use has revealed unexpected pathways to IgE memory in the mouse. Here, we review these findings and consider their bearing on our understanding of IgE memory and allergic disease in man.

Defective innate immune responses to respiratory syncytial virus infection in ovalbumin-sensitized mice

BACKGROUND/PURPOSE

Respiratory viral infections have frequently been reported to closely correlate with asthma exacerbations. Distinctive expression of cytokine/chemokine and anomalous responses of innate immunity induced by respiratory viral infections were suggested to play a key role. This study further evaluates the effects of airway sensitization on innate immunity in response to different viruses.

METHODS

Murine sensitization was established using an ovalbumin (OVA) sensitization model. Mice were subsequently infected with either respiratory syncytial virus (RSV) or human metapneumovirus (hMPV). Type I interferon (IFN), cytokines, and chemokines were measured in bronchoalveolar lavage (BAL) fluid. Pulmonary tissue samples were collected for the analysis of viral titers and type I IFN signal transcriptors.

RESULTS

Distinct expressions of cytokine/chemokine responses after viral infection were also found in mice with OVA sensitization. A significant increase of virus replication was found in lungs of RSV-infected sensitized mice. The increment of RSV titer was associated with the decreased levels of type I IFN. Although Toll-like receptor 3 (TLR3) expression was significantly increased in the lungs, the key signal transcriptor, IFN regulatory factor 3, was significantly suppressed in the RSV-infected sensitized mice.

CONCLUSION

A defective antiviral innate response was observed in the murine respiratory allergy model. Suppressed expression of IFN signal transcriptor contributes to decreased production of type I IFN. The defective innate immune response might result in acute viral exacerbations of allergic airway diseases.

Graphene oxide attenuates Th2-type immune responses, but augments airway remodeling and hyperresponsiveness in a murine model of asthma

Several lines of evidence indicate that exposure to nanoparticles (NPs) is able to modify airway immune responses, thus facilitating the development of respiratory diseases. Graphene oxide (GO) is a promising carbonaceous nanomaterial with unique physicochemical properties, envisioned for a multitude of medical and industrial applications. In this paper, we determined how exposure to GO modulates the allergic pulmonary response. Using a murine model of ovalbumin (OVA)-induced asthma, we revealed that GO, given at the sensitization stage, augmented airway hyperresponsiveness and airway remodeling in the form of goblet cell hyperplasia and smooth muscle hypertrophy. At the same time, the levels of the cytokines IL-4, IL-5, and IL-13 were reduced in broncho-alveolar lavage (BAL) fluid in GO-exposed mice. Exposure to GO during sensitization with OVA decreased eosinophil accumulation and increased recruitment of macrophages in BAL fluid. In line with the cytokine profiles, sensitization with OVA in the presence of GO stimulated the production of OVA-specific IgG2a and down-regulated the levels of IgE and IgG1. Moreover, exposure to GO increased the macrophage production of the mammalian chitinases, CHI3L1 and AMCase, whose expression is associated with asthma. Finally, molecular modeling has suggested that GO may directly interact with chitinase, affecting AMCase activity, which has been directly proven in our studies. Thus, these data show that GO exposure attenuates Th2 immune response in a model of OVA-induced asthma, but leads to potentiation of airway remodeling and hyperresponsiveness, with the induction of mammalian chitinases.

Serum levels of the CC chemokines CCL2, CCL5, and CCL11 in food allergic children with different clinical manifestations

Food allergies (FA) are frequent in 8 % of children under 3 years old and approximately 2 % of adults. Chemokine are involved in various allergies such as FA. The present study was aimed to determine CCL2, CCL5, and CCL11 levels in FA. The study population of this cross-sectional study contained 63 patients suffering from FA and 100 healthy controls. Concentrations of CCL2, CCL5, CCL11, and IgE were measured by enzyme-linked immunosorbent assay (ELISA). Eosinophils were counted using Casy Ι cell counter + analyzer system model SCAREF system GmbH. Differences were considered significant at P < 0.05. Current results showed that FA patients had significantly elevated numbers of circulating periphery eosinophils than the disease-free controls. Serum IgE levels in FA patients were also higher than controls. We also showed that serum levels of CCL2 and CCL11 were significantly enhanced in FA patients compared to control but CCL5 was not detectable. Results of present study revealed that both CCL2 and CCL11 were more elevated in FA children suffering from anaphylaxis and urticaria than bronchial asthma and atopic dermatitis. These results also indicated that more increased levels of CCL2 and CCL11 were observed following consumption of cow's milk and pistachio nuts. Overall, findings of the present study proposed that serum levels of CCL2 and CCL11 are elevated in FA and these may be considered as useful parameters in diagnosis of disorder. It is also possible to design treatments on the basis of blocking of chemokines expression by application of antibodies against them to overcome allergic complications in patients suffering from FA.

Assessment of inhibitory potential of Pothos scandens L. on ovalbumin-induced airway hyperresponsiveness in balb/c mice

Pothos scandens L. was used in Indian traditional medicine as an antiasthmatic drug. The ethanolic and aqueous extracts were prepared with aerial parts of P. scandens (PSE & PSA). ESI MS/MS of PSE ethanolic extract was carried out for the determination of chemical constituents. CP1 is isolated from the PSE, structurally confirmed with NMR and LCMS/MS. PSE, PSA and CP1 are evaluated against ovalbumin (OVA) induced airway hyperresponsiveness (AHR) in balb/c mice. The test drugs are administered p.o. prior to challenge with aerosolized 2.5% w/v OVA. Total and differential leucocyte count, nitrite (NO2), nitrate (NO3), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-13 (IL-13) are estimated in bronchoalveolar lavage fluid (BALF). Similarly, myeloperoxidase (MPO), malonaldehyde (MDA) and total lung protein (TLP) are estimated in the lungs. The results reveal a significant increase in total and differential leucocyte count, NO2, NO3, TNF-α, IL-6, and IL-13 in OVA induced AHR. However, these parameters are significantly decreased in PSE and PSA tested doses (PSE 100 & 200mg/kg). While, treatment with CP1 is less effective at 5 & 10mg/kg doses. Similar observations obtain for MPO and MDA in lungs. However, the mean value indicated that the PSE at 200mg/kg showed a significant restoration in all the parameters. Pro-inflammatory mediators are known to be responsible for AHR. Histopathology revealed justifies the effectiveness. The present investigations suggest PSE are interesting molecules for further research for asthma, with an approach through pro-inflammatory inhibitory pathway. P. scandens is a potential herbal medicine for allergy induced asthma.

A phase 1, randomized, placebo-controlled, dose-escalation study of an anti-IL-13 monoclonal antibody in healthy subjects and mild asthmatics

AIMS

IL-13 is implicated as an important mediator of the pathology of asthma. This first clinical study with GSK679586, a novel humanized anti-IL-13 IgG1 monoclonal antibody, evaluated the safety, pharmacokinetics and pharmacodynamics of escalating single and repeat doses of GSK679586.

METHODS

In this randomized, double-blind study, healthy subjects received single intravenous infusions of GSK679586 (0.005, 0.05, 0.5, 2.5, 10 mg kg(-1)) or placebo and mild intermittent asthmatics received two once monthly intravenous infusions of GSK679586 (2.5, 10, 20 mg kg(-1)) or placebo.

RESULTS

GSK679586 displayed approximately linear pharmacokinetics (based on AUC and C(max)) with limited accumulation upon repeat administration. In mild intermittent asthmatics, treatment with GSK679586 produced an increase in serum total IL-13 concentrations, indicative of GSK679586-IL-13 complex formation. Additionally, mean levels of exhaled nitric oxide (FeNO), a marker of pulmonary inflammation, were reduced relative to baseline at 2.5, 10 and 20 mg kg(-1) doses of GSK679586 at both 2 weeks (19%, 44% and 52% decreases) and 8 weeks (29%, 55% and 42% decreases) after the second infusion. GSK679586 was well tolerated; the incidence of AEs was comparable across all presumed biologically active doses and there were no treatment-related SAEs.

CONCLUSIONS

GSK679586 demonstrated dose-dependent pharmacological activity in the lungs of mild intermittent asthmatics. These findings, together with the favourable safety profile and advantageous PK characteristics of a monoclonal antibody (e.g. a long half-life supporting less frequent dosing), warrant further investigation of GSK679586 in a broader asthma patient population.

Marine macro- and microalgae as potential agents for the prevention of asthma: hyperresponsiveness and inflammatory subjects

Asthma is a variable disease and various factors are affected to increase the asthmatic symptoms and level of asthma control. It is believed that the cause for this disease is a combination of genetic and environmental factors. Numerous medications are available at present to treat this disease but it has been failed to control number of incidences successfully. Hence, recently many researchers have paid their interest to identify potential drugs from marine-based resources such as marine algae. In vitro and in vivo experiments have been conducted with extracts or compounds from algae and found that they showed significant activities against asthma. Accordingly, many marine macro- and microalgae have been reported to have potential to ameliorate the effect of asthma. However, detailed studies are needed in relation to identify the molecular mechanism of this disease to apply those marine resources against asthma effectively. In this chapter, an attempt has been taken to discuss the potential antiasthmatic activity of marine macro- and microalgae.

Treatment of asthma and food allergy with herbal interventions from traditional chinese medicine

Prevalence of asthma and allergy has increased over the past 2-3 decades in Westernized countries. Despite increased understanding of the pathogenesis of asthma and allergic diseases, control of severe asthma is still difficult. Asthma is also associated with a high prevalence of anxiety, particularly in adolescents. There is no effective treatment for food allergy. Food allergy is often associated with severe and recalcitrant eczema. Novel approaches for treatment of asthma and food allergy and comorbid conditions are urgently needed. Traditional Chinese medicine, used in Asia for centuries, is beginning to play a role in Western healthcare. There is increasing scientific evidence supporting the use of traditional Chinese medicine for asthma treatment. Since 2005, several controlled clinical studies of "antiasthma" herbal remedies have been published. Among the herbal medicines, antiasthma herbal medicine intervention is the only antiasthma traditional Chinese medicine product that is a Food and Drug Administration investigational new drug that has entered clinical trials in the United States. Research into the effects and mechanisms of action of antiasthma herbal medicine intervention in animal models is actively being pursued. Research on traditional Chinese medicine herbal medicines for treating food allergy is rare. The herbal intervention Food Allergy Herbal Formula-2 is the only Food and Drug Administration botanical investigational new drug under investigation as a multiple food allergy therapy. This review article discusses promising traditional Chinese medicine interventions for asthma, food allergy, and comorbid conditions, and explores their possible mechanisms of action.

What is unique about the IgE response?

IgE antibodies are involved in allergic reactions. High affinity IgE antibodies can cause anaphylaxis when cross-linked by minute amounts of antigen. The issue of how the IgE response is initiated and maintained is addressed in this review. A model has been proposed by which IgE(+) cells expressing antibodies that bind with high affinity to their antigens are generated through an IgG1 intermediate, which goes through affinity maturation in germinal centers (GC) before undergoing sequential switching to IgE. Mice deficient in IgG1 produce IgE at almost normal levels, but the IgE antibodies produced in IgG1-deficient mice lack the antigen-binding strength and the somatic mutations associated with affinity maturation. A GFP reporter strain, which expresses a modified IgE molecule, was recently developed and was utilized to challenge the sequential switching model. Several molecules that are highly expressed in GC can antagonize class switching to IgE in GC antagonize partially class switching to IgE; in addition, GC IgE(+) cells are gradually lost from GC as the immune response progresses, as shown with another recently developed, Venus-expressing IgE reporter mouse strain. In contrast, as a population, IgG1 cells thrive in the GC environment. Membrane IgE-expressing plasmablasts and plasma cells (PC) were recognized as a major component of the IgE response in secondary lymphoid organs. The swift development of IgE cells toward the PC fate, together with the affinity maturation of the IgE response via an IgG intermediate, represent the most salient features of the IgE immune responses, which make them distinct from IgG responses.

Immature B cells preferentially switch to IgE with increased direct Sμ to Sε recombination

To be added.

Immunoglobulin heavy chain (IgH) class-switch recombination (CSR) replaces initially expressed Cμ (IgM) constant regions (C_H) exons with downstream C_H exons. Stimulation of B cells with anti-CD40 plus interleukin-4 induces CSR from Cμ to Cγ1 (IgG1) and Cε (IgE), the latter of which contributes to the pathogenesis of atopic diseases. Although Cε CSR can occur directly from Cμ, most mature peripheral B cells undergo CSR to Cε indirectly, namely from Cμ to Cγ1, and subsequently to Cε. Physiological mechanisms that influence CSR to Cγ1 versus Cε are incompletely understood. In this study, we report a role for B cell developmental maturity in IgE CSR. Based in part on a novel flow cytometric IgE CSR assay, we show that immature B cells preferentially switch to IgE versus IgG1 through a mechanism involving increased direct CSR from Cμ to Cε. Our findings suggest that IgE dysregulation in certain immunodeficiencies may be related to impaired B cell maturation.

Interleukin-4 (IL-4) and IL-13 suppress excessive neutrophil infiltration and hepatocyte damage during acute murine schistosomiasis japonica

Due to the importance of neutrophils and proinflammatory cytokines in schistosomal liver damage, we analyzed the mechanisms underlying neutrophil and proinflammatory responses in murine schistosomiasis japonica. We found that granulomatous inflammation around parasite eggs in the liver was greater in Schistosoma japonicum-infected IL-4-/- IL-13-/- (double-knockout [DKO]) mice than in infected wild-type (WT) mice at 6 weeks, but not at 8 weeks, postinfection, suggesting the importance of Th2 responses in these typical hepatic lesions. Infected DKO mice also showed increased neutrophil infiltration accompanying more severe pathology, as shown by the enhanced necrosis of hepatocytes. This was not likely due to a Th1/Th2 imbalance, because there was no detectable increase in gamma interferon (IFN-γ) production in these DKO mice. mRNA expression of interleukin-17A (IL-17A), proinflammatory cytokines, and the neutrophil chemoattractant CXCL2 in liver was higher in infected DKO mice than in WT mice. However, in IL-4-/- IL-13-/- IL-17A-/- (triple-knockout [TKO]) mice, the absence of IL-17A was associated with only marginal differences in schistosomal liver damage, suggesting that IL-17A is only partially responsible for neutrophil-driven hepatic damage. Furthermore, the expression of mRNAs encoding proinflammatory cytokines was not under the control of IL-17A in TKO mice. These findings indicate that IL-4 and IL-13 suppress excessive neutrophil recruitment, proinflammatory cytokine production, and hepatic damage during the acute stage of S. japonicum infection, suggesting that neutrophils and proinflammatory cytokines are mainly responsible for hepatocyte damage during acute murine schistosomiasis japonica. However, neutrophil induction and the production of proinflammatory cytokines were not due solely to IL-17A.

Harnessing opportunities in non-animal asthma research for a 21st-century science

The incidence of asthma is on the increase and calls for research are growing, yet asthma is a disease that scientists are still trying to come to grips with. Asthma research has relied heavily on animal use; however, in light of increasingly robust in vitro and computational models and the need to more fully incorporate the 'Three Rs' principles of Replacement, Reduction and Refinement, is it time to reassess the asthma research paradigm? Progress in non-animal research techniques is reaching a level where commitment and integration are necessary. Many scientists believe that progress in this field rests on linking disciplines to make research directly translatable from the bench to the clinic; a '21st-century' scientific approach to address age-old questions.

The Role of Plasmacytoid and Myeloid Dendritic Cells in Induction of Asthma in a Mouse Model and the Effect of a TLR9 Agonist on Dendritic Cells

Purpose

To determine the role of plasmacytoid dendritic cells (pDC) and myeloid dendritic cells (mDC) in priming effector T cells to induce allergy, and to evaluate the effect of immunostimulatory sequences (ISS, TLR9 agonist) on dendritic cells.

Methods

Cultured mDC and pDC with/without ISS were injected intratracheally into sensitized Balb/C mice. Mice were sacrificed, and then pulmonary function tests, bronchoalveolar lavage (BAL), cell counts, and cytokine levels were evaluated. Migration of dendritic cells was also evaluated after ISS administration.

Results

In mice injected with mDC, airway hyperresponsiveness, eosinophil counts, and Th2 cytokine levels in BAL increased with increasing numbers of mDC injected. However, in mice injected with pDC, none of these changed, suggesting poor priming of T cells by pDC. In addition, mDC pulsed with ISS inhibited asthmatic reactions, and ISS administration inhibited migration of DC to the lung.

Conclusions

We suggest that pDC played a limited role in priming T cells in this asthma model and that mDC played a major role in inducing asthma. In addition, ISS inhibited migration of DC to the lung.

Mouse CCL8, a CCR8 agonist, promotes atopic dermatitis by recruiting IL-5+ T(H)2 cells

Mouse CCL8 is a CC chemokine of the monocyte chemoattractant protein (MCP) family whose biological activity and receptor usage have remained elusive. Here we show that CCL8 is highly expressed in the skin, where it serves as an agonist for the chemokine receptor CCR8 but not for CCR2. This distinguishes CCL8 from all other MCP chemokines. CCL8 responsiveness defined a population of highly differentiated, CCR8-expressing inflammatory T helper type 2 (T(H)2) cells enriched for interleukin (IL)-5. Ccr8- and Ccl8-deficient mice had markedly less eosinophilic inflammation than wild-type or Ccr4-deficient mice in a model of chronic atopic dermatitis. Adoptive transfer studies established CCR8 as a key regulator of T(H)2 cell recruitment into allergen-inflamed skin. In humans, CCR8 expression also defined an IL-5-enriched T(H)2 cell subset. The CCL8-CCR8 chemokine axis is therefore a crucial regulator of T(H)2 cell homing that drives IL-5-mediated chronic allergic inflammation.

Role played by Th2 type cytokines in IgE mediated allergy and asthma

OBJECTIVE

Recent evidence suggest that allergen type 2 helper T cells (Th2) play a triggering role in the activation/recruitment of IgE antibody producing B cells, mast cells and eosinophils. Reduced microbial exposure in early life is responsible for a shift of Th1/Th2 balance in the immune system towards the pre-allergic Th2 response. The Th1 predominantly produce IFNgamma and delayed type hypersensitivity while Th2 secrete IL-4, IL-5, IL-6, IL-13 and regulate B cell and eosinophil mediated responses. To assess regulatory changes in the immune system, in patients with allergy and asthma, we studied the cytokine profile in serum in comparison with normal healthy controls.

PATIENTS AND METHODS

A total of 170 patients with various allergies and asthmatic conditions were studied, for cytokines in the serum by ELISA using kits from Immunotech, and analyzed to identify the triggering factors or main contributors towards allergy and asthma.

RESULTS

Our study showed increase in the levels of IL-4, IL-5 and IL-6 in all groups which were non- significant. But the levels of IL-10, IL-13 and TNF alpha were highly significant. Besides, we found correlation of GM-CSF with IL-10. Significant correlation with different cytokines was observed. Most of these patients showed increase in IgE levels.

CONCLUSIONS

This study gives a better understanding of how cytokines are the mediators of balance of Th1 and Th2 immune responses and IgE synthesis is controlled by cytokines. Further studies will eventually lead to improved treatment strategies in the clinical management of IgE mediated allergy.

Food aversion: a critical balance between allergen-specific IgE levels and taste preference

Animals sensitized to allergens change their feeding behavior and avoid drinking the otherwise preferred sweetened solutions containing the allergens. This phenomenon, known as food aversion, appears to be mediated by allergen-specific IgE antibodies. Here we investigated food aversion in BALB/c and C57BL/6 mice, which differ in their allergic responses to the allergen ovalbumin as well as in their preference for sweet taste. BALB/c mice present higher levels of IgE and a natural lower preference for sweet flavors when compared to C57BL/6 mice. Specifically, we studied a conflicting situation in which animals simultaneously experienced the aversive contact with the allergen and the attractive sweet taste of increasing concentrations of sucrose. We found that BALB/c mice were more prone to develop food aversion than C57BL/6 mice and that this aversive behavior could be abolished in both strains by increasing the palatability of the solution containing the allergen. In both strains food aversion was positively correlated with the levels of allergen-specific IgE antibodies and inversely correlated with their preference for sucrose sweetened solutions.

Splanchnic Th(2) and Th(1) cytokine redistribution in microsurgical cholestatic rats

BACKGROUND

Long-term extrahepatic cholestasis in the rat induces ductular proliferation and fibrosis in the liver, portal hypertension, splenomegaly, portosystemic collateral circulation, and ascites. These splanchnic alterations could have an inflammatory pathophysiology.

MATERIAL AND METHODS

We measured serum levels of hepatobiliary injury markers and the acute phase proteins, alpha-1-major acid protein (alpha(1)-MAP) and alpha-1-acid glycoprotein (alpha(1)-GPA) in rats 6 wk after microsurgical extrahepatic cholestasis. We also assayed Th(1) (TNF-alpha and IL-1beta) and Th(2) (IL-4 and IL-10) cytokine levels in the liver, ileum, spleen, and mesenteric lymph complex by enzyme-linked immunosorbent assay (ELISA) techniques. Liver fibrosis was measured by Sirius red stain and by using an image system computer-assisted method and mast cell liver infiltration by Giemsa stain.

RESULTS

The cholestatic rats showed an increase (P<0.001) in serum levels of bile acids, total and direct bilirubin, AST, ALT, AST/ALT index, gamma-GT, alkaline phosphatase, alpha(1)- MAP, alpha(1)-GPA, and LDH (P<0.05) in relation to sham-operated rats. TNF-alpha, IL-1beta, IL-4, and IL-10 increased in the ileum (P<0.01) and mesenteric lymph complex (P<0.001), and decreased in the liver (P<0.001). A marked bile proliferation associated with fibrosis (P<0.001) and mast cell infiltration was also shown in the liver of cholestatic rats.

CONCLUSION

The splanchnic redistribution of cytokines, with an increase of Th(1) and Th(2) production in the small bowel and in the mesenteric lymph complex, supports the key role of inflammatory mechanisms in rats with secondary biliary fibrosis.

An anti-inflammatory role for plasmacytoid dendritic cells in allergic airway inflammation

It was previously shown that administration of recombinant human Fms-like tyrosine kinase receptor-3 ligand (Flt3L) before allergen challenge of sensitized mice suppresses the cardinal features of asthma through unclear mechanisms. Here, we show that Flt3L dramatically alters the balance of conventional to plasmacytoid dendritic cells (pDCs) in the lung favoring the accumulation of pDCs. Selective removal of pDCs abolished the antiinflammatory effect of Flt3L, suggesting a regulatory role for these cells in ongoing asthmatic inflammation. In support, we found that immature pDCs are recruited to the lungs of allergen-challenged mice irrespective of Flt3L treatment. Selective removal of pDCs during allergen challenge enhanced airway inflammation, whereas adoptive transfer of cultured pDCs before allergen challenge suppressed inflammation. Experiments in which TLR9 agonist CpG motifs were administered in vitro or in vivo demonstrated that pDCs were antiinflammatory irrespective of their maturation state. These effects were mediated through programmed death-1/programmed death ligand 1 interactions, but not through ICOS ligand, IDO, or IFN-alpha. These findings suggest a specialized immunoregulatory role for pDCs in airway inflammation. Enhancing the antiinflammatory properties of pDCs could be employed as a novel strategy in asthma treatment.

Anti-asthmatic effect of marine red alga (Laurencia undulata) polyphenolic extracts in a murine model of asthma

The aim of the present work is focused on protective effects of an edible red alga, Laurencia undulata ethanolic (EtOH) extracts (LU) containing a large amount of polyphenols against OVA-induced murine allergic airway reactions using in vivo histological and cytokine assay. Mice sensitized and challenged with ovalbumin (OVA) showed typical asthmatic reactions as follows: an increase in the number of eosinophil in bronchoalveolar lavage fluid; a marked influx of inflammatory cells into the lung around blood vessels and airways, and airway luminal narrowing; the development of airway hyperresponsiveness; the detection of TNF-alpha and Th2 cytokines, such as IL-4 and IL-5 in the bronchoalveolar lavage (BAL) fluid; and detection of allergen-specific IgE in the serum. The successive intraperitoneal administration of LU before the last airway OVA-challenge resulted in a significant inhibition of all asthmatic reactions. These results suggest that L. undulata polyphenolic extracts possess therapeutic potential for combating bronchial asthma associated with allergic diseases.

Daclizumab improves asthma control in patients with moderate to severe persistent asthma: a randomized, controlled trial

RATIONALE

Airway inflammation in asthma is associated with increased activated CD25(+) T cells, IL-2, and soluble IL-2 receptors (IL-2Rs).

OBJECTIVES

A randomized, double-blinded, placebo-controlled study was used to evaluate the safety and efficacy of daclizumab, a humanized IgG1 monoclonal antibody against the IL-2R alpha chain (CD25) of activated lymphocytes, in adults with moderate to severe persistent asthma.

METHODS

Patients with obstructive pulmonary functions, despite inhaled corticosteroids (ICS), were switched to equivalent dose inhaled triamcinolone acetate acetonide (TAA). Patients dependent on ICS were randomized (3:1) to daclizumab (intravenous loading dose, 2 mg/kg, then 1 mg/kg) or placebo every 2 weeks, added to stable-dose TAA through Week 12 (Treatment Period 1). Over Weeks 12-20 (Treatment Period 2), patients tapered TAA while on the study drug, and were followed for 16 weeks off the study drug.

MEASUREMENTS AND MAIN RESULTS

Among 115 evaluable patients (88 daclizumab, 27 placebo), groups had similar age, disease duration, and length of ICS use. During Treatment Period 1, daclizumab improved FEV(1) (daclizumab, 4.4 +/- 1.80% vs. placebo, 1.5 +/- 2.39%; P = 0.05), and reduced daytime asthma symptoms (P = 0.018) and short-acting inhaled beta(2)-agonist use (P = 0.009). Daclizumab treatment prolonged time to exacerbation (P = 0.024). Adverse events were evenly distributed between groups, although there were more serious adverse events in the patients treated with daclizumab.

CONCLUSIONS

Daclizumab improved pulmonary function and asthma control in patients with moderate to severe chronic asthma inadequately controlled on ICS. The mechanism of action likely involves inhibition of proinflammatory cytokine generation by IL-2R blockade in activated T cells. Clinical trial registered with www.clinicaltrials.gov (NCT00028288).

The neutrophil-activating protein of Helicobacter pylori down-modulates Th2 inflammation in ovalbumin-induced allergic asthma

The Helicobacter pylori neutrophil-activating protein (HP-NAP) is able in vitro to elicit IL-12 and IL-23 production via agonistic interaction with toll-like receptor 2, and to promote Th1 polarization of allergen-specific T-cell responses. This study was aimed to assess whether systemic/intraperitoneal and/or mucosal HP-NAP administration inhibited the Th2-mediated bronchial inflammation using a mouse model of allergic asthma induced by inhaled ovalbumin (OVA). Systemic HP-NAP delivery markedly reduced the lung eosinophilia in response to repeated challenge with aerosolized OVA. Likewise, the production of IL-4, IL-5 and GM-CSF was significantly lower in the bronchoalveolar lavage of animals treated with systemic HP-NAP plus OVA than that of animals treated with OVA alone. Systemic HP-NAP also significantly resulted in both reduction of total serum IgE and increase of IL-12 plasma levels. Mucosal administration of HP-NAP was equally successful as the systemic delivery in reducing eosinophilia, IgE and Th2 cytokine levels in bronchoalveolar lavage. However, no suppression of lung eosinophilia and bronchial Th2 cytokines was observed in toll-like receptor 2-knock-out mice following HP-NAP treatment. These results identify HP-NAP as a candidate for novel strategies of prevention and treatment of allergic diseases.

Is obesity associated with an increased risk for airway hyperresponsiveness and development of asthma?

We investigated the association between airway hyperresponsiveness (AHR) and obesity in adults referred for confirmation of asthma diagnosis. Data were analyzed for obesity class I (body mass index [BMI] 30-34.9 kg/m²), class II (BMI ≥ 35-39.9 kg/m²), and class III (BMI ≥ 40 kg/m²). Of 861 subjects, 401 demonstrated AHR; the mean dose of methacholine was 4.16 ± 2.55 mg/mL. A significant association between obesity and AHR was evident for all subjects: the odds ratio was 1.37 (95% CI 1.02-1.82; p = .0317). One unit of increased BMI (1 kg/m²) was associated with a 3.1% increase in AHR risk (95% CI 1.01-1.05, p < .005). The odds ratio increased from 1.86 (95% CI 1.27-1.76; p = .0012) for class I to 2.61 (95% CI 1.48-4.60; p = .0006) for class III. Obesity was found to be associated with AHR and appears to be a risk factor for asthma.

Toll-like receptors in the respiratory system: their roles in inflammation

Allergic airway inflammation develops in the context of innate immune cells that express Toll-like receptors (TLRs). TLRs recognize microbial components and evoke diverse responses in immune and other respiratory cells through distinct signaling pathways. Bacterial and viral infection in the airway modulates the extent of allergic inflammation. TLR stimulation controls T helper (Th) 1, Th2, and Th17 cell differentiation, cytokine production in mast cells, and activation of eosinophils via direct and indirect pathways. TLR signals in dendritic cells increase expression of major histocompatibility complex proteins and T-cell coreceptors, resulting in greater T-cell activation with Th1 bias. TLR signals in mast cells increase their release of IL-5, and TLR signals in airway epithelial cells enhance airway generation of proallergic cytokines. Although these responses play an important protective role in infection, they may exacerbate allergic inflammation. Under some conditions, TLR stimulation, especially via TLR9, reduces Th2-dependent allergic inflammation through induction of Th1 responses. Therefore, understanding the regulatory role of TLRs in the pathogenesis of allergic airway inflammation may shed light on improving inflammation control in asthmatic patients.

Progress in allergy signal research on mast cells: regulation of allergic airway inflammation through toll-like receptor 4-mediated modification of mast cell function

In a mouse experimental asthma model, the administration of bacterial lipopolysaccharide (LPS), particularly at low doses, enhances the levels of ovalbumin (OVA)-induced eosinophilic airway inflammation. In an effort to clarify the cellular and molecular basis for the LPS effect, we demonstrate that the OVA-induced eosinophilic inflammation in the lung is dramatically increased by administration of LPS at the priming phase in wild-type mice, whereas such an increase was not observed in mast cell deficient mice. Adoptive transfer of bone marrow-derived mast cells (BMMC) from wild type but not from Toll-like receptor 4 (TLR4)-deficient mice restored the increased eosinophilic inflammation in mast cell-deficient mice. Moreover, in vitro analysis revealed that treatment of BMMC with LPS resulted in sustained up-regulation of GATA1 expression and increased production of Th2 cytokines (IL-4, IL-5, and IL-13) upon restimulation. Thus, mast cells appear to control allergic airway inflammation after their activation and modulation through TLR4-mediated induction of GATA1 proteins and subsequent increase in Th2 cytokine production.

A recombinant DNA plasmid encoding the human interleukin-5 breaks immunological tolerance and inhibits airway inflammation in a murine model of asthma

BACKGROUND

Eosinophils play a pivotal role in the generation of asthma inflammation. Interleukin (IL)-5 is the major activator of eosinophils. We hypothesize that modulating IL-5 activity could be an effective strategy for asthma therapy. In this study, we tested whether the plasmid encoding human IL-5 as a xenogeneic DNA vaccine could induce the production of autoantibodies, and be used for asthma treatment.

METHODS

A eukaryotic plasmid encoding the human IL-5 was constructed, and used as a DNA vaccine. A mouse model of asthma was established to observe its antiasthma activities. Eosinophils in tissue, blood and the bronchoalveolar lavage were stained and counted. Airway hyperresponsiveness (AHR) was determined by whole body plethysmography. Antibody characters and cytokines were detected with immunological methods.

RESULTS

Immunization with a plasmid encoding the human IL-5 as DNA vaccine reduced airway inflammation, reversed Th2 cytokines, and decreased AHR in mice. In addition, this immunization induced the production of polyclonal antibodies that were cross-reactive with native murine IL-5, and IgG1 and IgG2a were the major subclasses. Adoptive transfer of the purified antibodies from the sera of mice immunized with the plasmid encoding the human IL-5 resulted in similar antiasthma effects.

CONCLUSIONS

Our results suggest that active vaccination against IL-5 may be a rational therapeutic approach for the treatment of asthma and potentially other eosinophilic disorders.

The role of mast cells in atopy: what can we learn from canine models? A thorough review of the biology of mast cells in canine and human systems

Mast cell research has largely focused on the role of these cells in the early phase of allergic reactions. However, their involvement may well extend beyond this stage, and even reach across nonallergic conditions. Mast cells from different sources have helped advance our knowledge of their biology. Although in vitro and in vivo research in this area has mainly focused on humans, such studies are limited by the extent to which cells from certain human tissues and/or human patients can be collected or studied. While rodents also provide valuable models with which to further our understanding of the behaviour of mast cells and their contribution to allergy, reported differences between human and murine mast cells, and, in some instances, the limitations of in vivo rodent models of mast cell-mediated allergic conditions, preclude their use. In this review, we introduce a relatively unknown mast cell population, that of the dog. Canine mast cells display many phenotypic and functional similarities with their human counterparts, and dogs develop spontaneous and induced allergic diseases that share clinical and pathophysiological features with the human condition. Therefore, the use of canine cells can shed light on the general role of mast cells, particularly in relation to allergic diseases given the potential of in vivo dog models within this field. Here we provide a detailed review of the data reported from in vitro and in vivo studies of canine mast cells, and compare them with results obtained in human systems. We also highlight direct evidence of the mast cell contribution to canine atopy. We conclude that the dog offers useful in vitro and in vivo models in which to investigate mast cell behaviour, and that its use should be considered when undertaking studies aimed either at elucidating the role of mast cells in health and disease, or at prescreening novel therapies prior to entry into man.

Allergen-induced airway remodelling

Airway remodelling is associated with chronic asthma but it remains unclear whether it results from airway inflammation in response to allergens or immune-mediated events such as viral infections. Although the acute inflammation associated with asthma has been modelled extensively both in vitro and in vivo, the structural changes occurring in the lung have only recently been investigated. These in vitro, in vivo and in silico systems have been designed to examine the pathways leading to allergen-induced airway remodelling and have enabled investigators to draw conclusions about the participation of key cells and molecules in the development of allergen-induced airway remodelling. However, fundamental questions remain regarding the genesis of remodelling as well as the relationship between functional symptoms and pathological changes that occur. In this review the key questions relating allergen exposure to development of remodelling are discussed, as well as the steps that are being undertaken to investigate them.

Thymoquinone attenuates proinflammatory responses in lipopolysaccharide-activated mast cells by modulating NF-kappaB nuclear transactivation

Activated mast cells play an important role in the development and maintenance of chronic inflammation by releasing proinflammatory cytokines such as Tumor necrosis factor alpha (TNFalpha). TNFalpha is a key mediator of immune and inflammatory responses as it controls the expression of inflammatory genes network and its overproduction contributes significantly to the pathological complications observed in many inflammatory diseases. We have previously shown that thymoquinone (TQ), which has broad anti-inflammatory activities, attenuates allergic inflammation in mice. In the present study, we investigated the effect of TQ on LPS-induced TNFalpha production in the rat basophil cell line, RBL-2H3. Stimulation of RBL-2H3 cells with LPS markedly increased TNFalpha production. TQ treatment significantly inhibited LPS-induced TNFalpha mRNA expression and protein production. To understand the mechanism by which TQ inhibited TNFalpha production, we examined its effects on activation of NF-kappaB transcription factor, which has been shown to be involved in regulating TNFalpha responses. LPS activated the NF-kappaB pathway, resulting in accumulation of NF-kappaB p65 and p50 subunits in the nucleus and activation of TNFalpha promoter. TQ administration to LPS-stimulated cells did not noticeably alter NF-kappaB cytosolic activation or nuclear expression as demonstrated by western blot analysis. Instead, TQ significantly increased the amount of the repressive NF-kappaB p50 homodimer, and simultaneously decreased the amount of transactivating NF-kappaB p65:p50 heterodimer, bound to the TNFalpha promoter as revealed by electrophoretic mobility shift and chromatin immunoprecipitation assays. Transient transfection of RBL-2H3 cells with TNFalpha promoter-driven luciferase gene constructs demonstrated that one of the three NF-kappaB binding sites in the TNFalpha promoter, the kappaB3 site, played a major role in the induction of TNFalpha promoter-driven luciferase gene expression by LPS, as well as in mediating the inhibitory effects of TQ on TNFalpha production, as TQ had minimal effect on the TNFalpha promoter-luciferase construct that lacks the kappaB3 site. Together, these results suggest that TQ attenuates the proinflammatory response in LPS-stimulated mast cells by modulating nuclear transactivation of NF-kappaB and TNFalpha production.

Multitargeted approach using antisense oligonucleotides for the treatment of asthma

Asthma is characterized by inflammation and hyperresponsiveness related to the accumulation of inflammatory cells, particularly eosinophils, within the airways. We tested the hypothesis that a multitargeted approach is better than a single-targeted approach in a rat model of asthma. We simultaneously delivered oligonucleotides (ODNs) targeting the chemokine receptor CCR3 and the common beta chain subunit of the receptors for IL-3, IL-5, and GM-CSF at the time of ovalbumin challenge in sensitized Brown Norway rats. Fewer eosinophils were detected in bronchoalveolar lavage (BAL) of rats treated with both ODNs as compared to each ODN alone. Moreover, airway responsiveness to LTD(4) was significantly decreased at lower doses in the 2 ODN-treated groups compared to a single ODN. As ODN therapy has raised concerns of toxicity we therefore examined ODNs prepared with modified DNA bases, specifically 2'amino, 2'deoxyadenosine (DAP) in place of adenosine. In vivo, administration of individual DAP-ODN was efficacious in inhibiting airway hyperresponsiveness, whereas delivery of 2 DAP-ODNs (targeting CCR3 and common beta chain) reduced the influx not only of eosinophils but also lymphocytes and macrophages in the lungs of rats as compared to the unmodified ODNs. Blocking multiple inflammatory pathways simultaneously is more effective in preventing eosinophilia and airway hyperresponsiveness than inhibiting either pathway alone. The challenges associated with the development of a product containing two oligonucleotides in humans are discussed.

Role of TNFalpha in pulmonary pathophysiology

Tumor necrosis factor alpha (TNFα) is the most widely studied pleiotropic cytokine of the TNF superfamily. In pathophysiological conditions, generation of TNFα at high levels leads to the development of inflammatory responses that are hallmarks of many diseases. Of the various pulmonary diseases, TNFα is implicated in asthma, chronic bronchitis (CB), chronic obstructive pulmonary disease (COPD), acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). In addition to its underlying role in the inflammatory events, there is increasing evidence for involvement of TNFα in the cytotoxicity. Thus, pharmacological agents that can either suppress the production of TNFα or block its biological actions may have potential therapeutic value against a wide variety of diseases. Despite some immunological side effects, anti-TNFα therapeutic strategies represent an important breakthrough in the treatment of inflammatory diseases and may have a role in pulmonary diseases characterized by inflammation and cell death.

TLR9-based immunotherapy for allergic disease

A significant amount of data generated over the last few years supports the contention that Toll-like receptor (TLR) 9-based immunotherapy is effective in the prevention and treatment of animal models of allergic disorders. We will review here our experience with two distinct therapeutic strategies: TLR9-based immunomodulation and TLR9-based vaccination. Immunomodulation of allergic inflammation by TLR9 ligand (TLR9-L) is transient. It prevents both the early and late phases of the allergic reaction in experimental models of allergic asthma, rhinitis, and conjunctivitis. It also reverses ongoing allergic inflammation. Indoleamine 2.3-dioxygenase, the rate-limiting enzyme of tryptophan, is induced by TLR9-L and mediates, in part, these anti-inflammatory effects. TLR9-based immunomodulation is independent of allergens and, therefore, has a potential therapeutic advantage in a broad spectrum of allergic patients. On the other hand, TLR9-based vaccination therapy is an allergen-specific mode of immunotherapy, which provides long-term inhibition of allergen-specific hypersensitivities. Current clinical trials with TLR9-based immunotherapy demonstrate high immunogenic and therapeutic efficacy, as well as improved safety when compared with conventional allergen desensitization. Thus, if proven efficient, therapeutic strategies with TLR9-L may revolutionize the current treatment of allergic diseases.

Defining and adjusting divergent host responses to viral infection

Our laboratory focuses on the signal-transduction basis for mucosal immunity, inflammation, and remodeling, especially in relation to respiratory viral infection. Our approach aims to answer two major questions: (1) What are the mechanisms that control common viral infections? and (2) How can these transient infections cause long-term diseases, such as asthma? Our studies show that antiviral defense depends critically on a specialized network of mucosal epithelial cells and macrophages. When this network is compromised, the host is highly susceptible to infection, but when it is engineered to be broadly hyperresponsive to interferon, the host is markedly resistant to otherwise lethal viral infections. Similar but less effective hyperresponsiveness appears in asthma, suggesting that evolving attempts to improve antiviral defense may instead cause inflammatory disease. Indeed, in susceptible genetic backgrounds, respiratory viruses can also cause a hit-and-run phenomenon that is manifest by the development of a permanent asthmatic phenotype long after the infection has been cleared. This complex phenotype can be segregated into individual traits using pharmacologic, immunologic, and genetic strategies to achieve more precise definition of just how viruses can reprogram host behavior. Evidence of reprogramming is manifest by persistent abnormalities in epithelial cell survival and macrophage activation that when corrected can prevent the development of disease phenotypes. Our results led us to pursue the hypothesis that specific components of the innate immune system may manifest an aberrant antiviral response as a basis for chronic inflammatory diseases and that adjusting this response can improve short- and long-term outcomes after viral infection.