Design of peptides with high affinity binding to a monoclonal antibody as a basis for immunotherapy.

About half of the US population is sensitized to one or more allergens, as found by a National Health and Nutrition Examination Survey (NHANES). The most common treatment for seasonal allergic responses is the daily use of oral antihistamines, which can control some of the symptoms, but are not effective for nasal congestion, and can be debilitating in many patients. Peptide immunotherapy is a promising new approach to treat allergic airway diseases. The small size of the immunogens cannot lead to an unwanted allergic reaction in sensitized patients, and the production of peptides with sufficient amounts for immunotherapy is time- and cost-effective. However, it is not known what peptides are the most effective for an immunotherapy of allergens. We previously produced a unique monoclonal antibody (mAb) E58, which can inhibit the binding of multiple groups of mAbs and human IgEs from patients affected by the major group 1 allergens of ragweed (Amb a 1) and conifer pollens (Jun a 1, Cup s 1, and Cry j 1). Here, we demonstrated that a combined approach, starting from two linear E58 epitopes of the tree pollen allergen Jun a 1 and the ragweed pollen allergen Amb a 1, and residue modifications suggested by molecular docking calculations and peptide design could identify a large number of high affinity binding peptides. We propose that this combined experimental and computational approach by structural analysis of linear IgE epitopes and peptide design, can lead to potential new candidates for peptide immunotherapy.

The anti-allergic potential of tea: a review of its components, mechanisms and risks.

Allergy is an immune-mediated disease with increasing prevalence worldwide. Regular treatment with glucocorticoids and antihistamine drugs for allergy patients is palliative rather than permanent. Daily use of dietary anti-allergic natural products is a superior way to prevent allergy and alleviate the threat. Tea, as a health-promoting beverage, has multiple compounds with immunomodulatory ability. Persuasive evidence has shown the anti-allergic ability of tea against asthma, food allergy, atopic dermatitis and anaphylaxis. Recent advances in potential anti-allergic ability of tea and anti-allergic compounds in tea have been reviewed in this paper. Tea exerts its anti-allergic effect mainly by reducing IgE and histamine levels, decreasing FcεRI expression, regulating the balance of Th1/Th2/Th17/Treg cells and inhibiting related transcription factors. Further research perspectives are also discussed.

Chronic Rhinosinusitis with Nasal Polyps: Targeting IgE with Anti-IgE Omalizumab Therapy.

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a complex, clinically heterogeneous and persistent inflammatory disorder of the upper airway. Detailed mechanistic insights into disease pathogenesis are lacking, but it is now accepted that local tissue IgE driven T2-high inflammatory pathways are critical to disease. The recent CRSwNP Phase 3 POLYP1 and POLYP2 replicate studies of blocking IgE with omalizumab confirmed rapid improvements in all clinical parameters of sinonasal disease, confirming a pivotal role for IgE driven inflammatory pathways in CRSwNP. This review summarises the biology of IgE in relation to CRSwNP. Insight into how IgE may drive CRSwNP is evaluated in the context of clinical improvements seen with omalizumab. The need for further studies using a broader patient and biomarker specific groups to aid more precise drug-patient selection alongside more detailed mechanistic studies of omalizumab in CRSwNP is highlighted.

Ligelizumab for the treatment of chronic spontaneous urticaria.

INTRODUCTION: Due to daily hives with itch, sleeplessness, and unforeseen development of angioedema, chronic spontaneous urticaria significantly impairs quality of life, often for years. Its management is challenging. In most cases, H1-antihistamines are not effective. Although the disease is not characterized by specific IgE antibodies against allergens, the last decade demonstrated that neutralizing IgE by using the monoclonal anti-IgE antibody Omalizumab is safe and effective. Nevertheless, symptoms are not controlled by Omalizumab in approximately one-fourth of patients. AREAS COVERED: This review is focused on Ligelizumab (QGE031), a next-generation non-triggering fully human monoclonal antibody, with higher affinity to IgE compared to Omalizumab. EXPERT OPINION: In chronic spontaneous urticaria, subcutaneous Ligelizumab once per month for five months has shown a clear dose-response relationship with respect to symptoms. Superiority over Omalizumab was noted whereas the safety profile was similar. Most common side effects were injection site reactions. In the near future, results from phase 3 trials, two of them including more than 1000 patients each, are awaited. Having a higher affinity to IgE and being more effective than Omalizumab, Ligelizumab has the potential to free chronic urticaria patients from year-long daily annoying symptoms that did not respond to standard therapy as recommended by current guidelines.

Promising Use of the New Biologics in the Management of Drug-Induced Hypersensitivity Reactions: Preliminary Approaches.

Biologics are an innovative class of drugs that can selectively influence immunological responses at a cellular level. Although their use is usually restricted to some specific diseases, such as autoimmune pathologies and tumors, their "off-label" administration has increased widely in the last years. Drug treatment may induce hypersensitivity reactions which currently lack any gold standard therapy but maybe a future field of application for biologics. Agents like anti-IgE (Omalizumab) and Tumor Necrosis Factor-α inhibitors might be used in immediate-type and cell-mediated hypersensitivity caused by medications, respectively, and the first trials in that direction are being reported in the literature. In fact, the refined immunological mechanisms involved in the pathogenesis of drug hypersensitivity might respond successfully to this new class of drugs.

Omalizumab for the Treatment of Persistent Drug Induced Urticaria Elicited by Thienopyridines: A Case Report.

The anti-IgE Omalizumab may be helpful to treat clopidogrel hypersensitivity without stopping thienopyridine administration in patients requirining continuous antiplatellet therapy after coronary stent placement.

Effects of Omalizumab on FcεRI and IgE Expression in Lesional Skin of Bullous Pemphigoid.

Recent studies suggest an important role of immunoglobulin E (IgE) as an alternative pathogenic pathway in the development of bullous pemphigoid (BP), as the most frequent subepidermal blistering disease of the skin Use of IgE targeted therapies, such as omalizumab, has been shown promising in recent studies. The aim of this study was to assess the effect of omalizumab on FcεRI and IgE expression on circulating basophils and on lesional intradermal cells in BP to generate insight into the immunological effects of omalizumab in BP. We report two cases of BP patients treated with omalizumab. Efficacy of treatment was assessed clinically 4 months after initiation of the therapy. Lesional and non-lesional skin biopsies where taken before and 4 weeks after initiation of omalizumab therapy. In addition, FcεRI expression on circulating cells and IgE levels in serum and in the skin samples, as well as anti-BP180 and anti-BP230 in serum and eosinophils and basophils counts in blood were assessed before and during treatment. Both patients showed a marked improvement after 4 months, with no adverse effects. Down-regulation of FcεRI, IgE in lesional skin and on circulating basophils were observed in parallel with clinical improvement. The current case study supports the role of omalizumab in the treatment of a subset of BP patients. Our observations suggest that omalizumab represents a valuable therapeutic option in the management of BP patients. Its efficacy might be related to reduction in FcεRI+ and IgE+ basophils and intradermal cells.

Pollen Allergy Suppression Effect by the Oral Administration of Acetic Acid Bacteria (Gluconacetobacter hansenii).

BACKGROUND/AIM: Gluconacetobacter hansenii (G. hansenii) is an acetic acid bacterium of vinegar production. Its anti-allergic effect on mice upon oral administration was examined. MATERIALS AND METHODS: The amount of LPS was measured by the Limulus reaction. Mice were sensitized by peritoneal and intranasal administration of cedar pollen and alum followed by oral administration of 30 or 150 mg/kg of heated G. hansenii cells. Pollen was administered intranasally to evaluate nasal symptoms, and at 8 weeks, IgE and IL-10 levels in blood were measured by ELISA. RESULTS: The amount of LPS in dried bacterial cells was 10.4±3.3 mg/g. In the cedar pollinosis model of mice, a significant reduction was observed in nose scratching of both groups administered with the bacterial cells (30, 150 mg/kg). CONCLUSION: G. hansenii contains LPS, and its oral administration showed an anti-allergic effect by a significant mitigation of the symptoms in a pollen allergy mouse model.

Preventive and therapeutic effects of Trichinella spiralis adult extracts on allergic inflammation in an experimental asthma mouse model.

BACKGROUND: Helminths immunomodulate the host immune system by secreting proteins to create an inhibitory environment as a strategy for survival in the host. As a bystander effect, this balances the host immune system to reduce hypersensitivity to allergens or autoantigens. Based on this, helminth therapy has been used to treat some allergic or autoimmune diseases. As a tissue-dwelling helminth, Trichinella spiralis infection has been identified to have strong immunomodulatory effects; the effective components in the worm have not yet been identified. METHODS: The soluble extracts of T. spiralis adult worms and muscle larvae were used to treat airway inflammation before and after an ovalbumin (OVA)-sensitization/challenge in an OVA-induced asthma mouse model. The therapeutic effects were observed by measuring the level of inflammation in the lungs. RESULTS: The soluble products derived from T. spiralis parasites, especially from adult worms, were able to ameliorate OVA-induced airway inflammatory responses which were associated with reduced eosinophil infiltration, OVA-specific IgE, Th2 cytokine IL-4, and increased IL-10 and TGF-ß. The stimulation of the Treg response may contribute to the alleviated allergic inflammation. CONCLUSIONS: Trichinella spiralis worm extracts stimulate regulatory cytokines that are associated with reduced allergic airway inflammation. The identification of effective components in the adult worm extracts will be a crucial approach for developing a novel therapeutic for allergic and autoimmune diseases.

Rapid subcutaneous desensitization for the management of delayed hypersensitivity reactions to omalizumab：A case report.

WHAT IS KNOWN AND OBJECTIVE: Omalizumab is effective as an add-on drug to treat severe persistent allergic asthma. However, delayed hypersensitivity reactions to omalizumab may deprive patients of its use. Rapid subcutaneous desensitization could be a solution. CASE DESCRIPTION: A 61-year-old man developed a delayed allergy to omalizumab after the first injection. A 14-step desensitization procedure was applied to the patient and was successful. WHAT IS NEW AND CONCLUSION: Delayed hypersensitivity reactions to omalizumab are rare, but they may cause the interruption of drug usage. Desensitization to omalizumab could be a possible solution.

Identification of the minimal region of peptide derived from ADP-ribosylation factor1 (ARF1) that inhibits IgE-mediated mast cell activation.

Mast cells play a pivotal role in allergic reactions and inflammations. Aggregation of the high affinity IgE receptor (FcεRI) eventually leads to the release of granule components such as histamine, as well as the de novo synthesis of inflammatory cytokines and lipid mediators. These substances are involved in the development of allergy and inflammation. Therefore, efficient inhibitors of mast cell activation would be therapeutically beneficial. We previously demonstrated that the synthetic peptide derived from the NH2-terminal region (2-17: GNIFANLFKGLFGKKE) of a small GTPase ARF1 (ADP-ribosylation factor1) inhibited FcεRI-induced mast cell degranulation. However, detailed structure-activity relationship study of NH2-terminal portion of ARF1 peptide has not been done. In addition, it is still unclear whether the NH2-terminal peptide of ARF1 suppresses FcεRI-induced production of cytokines and lipid mediators such as leukotriene C4 (LTC4) from mast cells. Here we show that amino acid residues K10-K16 are necessary for ARF1 peptide to efficiently inhibit FcεRI-induced activation of bone marrow-derived mast cells (BMMCs), indicated by decreased mast cell degranulation, cytokine secretion and leukotriene release. Furthermore, we show that ARF1 peptide inhibits IgE-mediated passive cutaneous anaphylaxis reaction. Our results suggest that the peptide derived from ARF1 could be developed into a novel anti-allergic agent for therapeutic intervention in allergy and mast cell-related pathologies.

Encapsulating an Immunosuppressant Enhances Tolerance Induction by Siglec-Engaging Tolerogenic Liposomes.

Unwanted antibody responses significantly impact human health, and current options for treating deleterious antibody responses largely rely on broad immunosuppressants that can compromise overall immunity. A desirable alternative is to induce antigen-specific immune tolerance. We have shown that co-presentation of antigen and ligands of B cell sialic acid-binding immunoglobulin-like lectins (Siglecs) on a liposomal nanoparticle induces antigen-specific tolerance. Although Siglec-engaging tolerance-inducing antigenic liposomes (STALs) induce robust B cell tolerance in naïve mice, the full potential of STALs requires long-term tolerance induction and suppression of an ongoing immune response. We hypothesized that STALs encapsulated with rapamycin (RAPA), an immunomodulator, could improve the efficacy of STALs and potentially enable their use in the context of immunological memory. Here, we showed that formulation of STALs with RAPA produced enhanced tolerance induction in naïve mice compared to STALs without RAPA but had minimal impact on inducing tolerance in previously sensitized mice. These findings indicate that the addition of immunomodulators to STALs could be beneficial in tolerance induction and support future development of STALs for the treatment of allergy and autoimmune diseases.

Evaluation of IgE Antibodies to Omalizumab (Xolair®) and Their Potential Correlation to Anaphylaxis.

Omalizumab (Xolair®) is a recombinant humanized monoclonal antibody that selectively binds to human immunoglobulin E (IgE). Omalizumab is used to treat IgE-mediated diseases such as chronic idiopathic urticaria (CIU) and moderate to severe allergic asthma. In pre-marketing clinical trials in patients with asthma, anaphylaxis was reported in 3 of 3,507 (0.1%) patients. In post-marketing spontaneous reports, the frequency of anaphylaxis attributed to omalizumab use was estimated to be at least 0.2% of patients based on an estimated exposure of about 57,300 patients from June 2003 through December 2006. To better understand the risk of anaphylaxis in patients with allergic asthma receiving omalizumab, a post-marketing pharmacosurveillance study was initiated in 2009. As part of this study, an assay was developed to detect antibodies of IgE isotype to omalizumab. Serum samples from patients in the study were evaluated using this assay. Our results indicated that there was no observable correlation between either anaphylaxis or skin test reactivity and the presence of antibodies of IgE isotype to omalizumab. Here, we discuss the development of this assay as well as the results of the immunogenicity assessment.

Anti-Allergic Activities of Smilax glabra Rhizome Extracts and Its Isolated Compounds.

BACKGROUND: The rhizomes of Smilax glabra (SG) has long been used in Traditional Chinese and Thai herbal medicine to treat a variety of infectious diseases and immunological disorders. OBJECTIVE: To investigate the in vitro anti-allergic activities of crude extracts andpure isolated flavonoid compounds from SG by determination of inhibitory effect on antigen-induced release of ß-hexosaminidasefrom RBL-2H3 cells. MATERIAL AND METHOD: The in vitro inhibitory effects ofcrude aqueous and organic extracts on ß-hexosaminidase release in RBL-2H3 cells were evaluated as an in vitro indication ofpossible anti-allergic activity. Bioassay-guided fractionation of extracts was used to isolate flavonoid compounds from the ethanolic extracts. RESULTS: The 95% and 50% ethanolic extracts of SG showed remarkably high anti-allergic activity, with IC50 values of 5.74 ± 2.44 and 23.54 ± 4.75 µg/ml, much higher activity than that for Ketotifen (IC50 58.90 µM). The water extract had negligible activity (IC50 > 100 µg/ml). The two isolated flavonols, Engeletin and Astilbin, showed weak anti-allergic activity, IC50 values 97.46 ± 2.04 and >100 µg/ml, respectively. CONCLUSION: The 95% and 50% ethanolic extracts of SG showed strong anti-allergic activity, but two flavonol constituents did not show any significant anti-allergic activity. These findings suggest that a combination of effects of various phytochemicals in crude extracts used in traditional medicine, are responsible for the purported anti-allergic activity of SG herbal preparations. The plethora of constituents in crude extracts, as yet unidentified, are likely to be acting synergistically to account for the strong observed anti-allergic in vitro activity.

Effects of nasal corticosteroids on boosts of systemic allergen-specific IgE production induced by nasal allergen exposure.

BACKGROUND: Allergen exposure via the respiratory tract and in particular via the nasal mucosa boosts systemic allergen-specific IgE production. Intranasal corticosteroids (INCS) represent a first line treatment of allergic rhinitis but their effects on this boost of allergen-specific IgE production are unclear. AIM: Here we aimed to determine in a double-blind, placebo-controlled study whether therapeutic doses of an INCS preparation, i.e., nasal fluticasone propionate, have effects on boosts of allergen-specific IgE following nasal allergen exposure. METHODS: Subjects (n = 48) suffering from grass and birch pollen allergy were treated with daily fluticasone propionate or placebo nasal spray for four weeks. After two weeks of treatment, subjects underwent nasal provocation with either birch pollen allergen Bet v 1 or grass pollen allergen Phl p 5. Bet v 1 and Phl p 5-specific IgE, IgG1-4, IgM and IgA levels were measured in serum samples obtained at the time of provocation and one, two, four, six and eight weeks thereafter. RESULTS: Nasal allergen provocation induced a median increase to 141.1% of serum IgE levels to allergens used for provocation but not to control allergens 4 weeks after provocation. There were no significant differences regarding the boosts of allergen-specific IgE between INCS- and placebo-treated subjects. CONCLUSION: In conclusion, the application of fluticasone propionate had no significant effects on the boosts of systemic allergen-specific IgE production following nasal allergen exposure. TRIAL REGISTRATION: http://clinicaltrials.gov/NCT00755066.

Small molecule analogues of the immunomodulatory parasitic helminth product ES-62 have anti-allergy properties.

ES-62, a glycoprotein secreted by the filarial nematode Acanthocheilonema viteae, exhibits anti-inflammatory properties by virtue of covalently attached phosphorylcholine moieties. Screening of a library of ES-62 phosphorylcholine-based small molecule analogues (SMAs) revealed that two compounds, termed 11a and 12b, mirrored the helminth product both in inhibiting mast cell degranulation and cytokine responses in vitro and in preventing ovalbumin-induced Th2-associated airway inflammation and eosinophil infiltration of the lungs in mice. Furthermore, the two SMAs inhibited neutrophil infiltration of the lungs when administered therapeutically. ES-62-SMAs 11a and 12b thus represent starting points for novel drug development for allergies such as asthma.

Identification of anti-allergic effect of Clonorchis sinensis-derived protein venom allergen-like proteins (CsVAL).

Previous studies demonstrated that Clonochis sinensis-derived crude antigens suppress development of allergic responses. We investigated the effects of C. sinensis venom allergen-like (CsVAL) proteins on immune-modulating activities in allergic inflammatory response. Using RBL-2H3 rat mast cells, we demonstrated that CsVAL inhibits antigen-induced ß-hexosaminidase release from immunoglobulin E-sensitized RBL-2H3 cells, and this inhibitory activity occurs by suppressing Lyn phosphorylation and intracellular reactive oxygen species production. In addition, CsVAL peptide treatment inhibits activation of protein kinase C-α and extracellular signal-regulated kinase 1/2, which are involved in degranulation of immunoglobulin E-sensitized mast cells. Furthermore, immunization with CsVAL suppressed development of skin inflammation by assessing ear thickness and cutaneous infiltration by eosinophils and mast cells in oxazolone-induced contact hypersensitivity in vivo mouse model. These results suggest that CsVAL is a promising candidate as an effective mast cell inhibitor for allergic and inflammatory diseases.

[Disease modification and duration of omalizumab treatment in patients with severe allergic asthma]. / Disease-Modifikation und Dauer einer Omalizumab-Therapie bei Patienten mit schwerem allergischen Asthma.

BACKGROUND AND METHODS: Omalizumab is a monoclonal anti-IgE-antibody that is used to treat severe allergic asthma. The aim of this review was to evaluate the available evidence in a panel of experts and to provide recommendations on therapy duration with omalizumab. RESULTS: A direct or indirect interaction between omalizumab and IgE production seems likely. Pharmacokinetic-pharmakodynamic models suggest that omalizumab modulates IgE production. This hypothesis is currently investigated in clinical studies. In addition, available evidence suggests that omalizumab mitigates different factors of airway remodeling. However, based on the currently available data, no recommendations can be given in regard to reduction of dosage or discontinuation of omalizumab in long term treated patients. CONCLUSIONS: Currently, neither dose reductions nor treatment withdrawal can be recommended in patients with severe allergic asthma and long term treatment with omalizumab. Clinical studies addressing these issues are being conducted.

Immunogenicity and safety of omalizumab in pre-filled syringes in patients with allergic (IgE-mediated) asthma.

BACKGROUND: Omalizumab, a humanised anti-immunoglobulin E monoclonal antibody for treatment of uncontrolled moderate-to-severe or severe persistent allergic asthma, was developed as a lyophilised powder for reconstitution. A liquid formulation in pre-filled syringes has now been developed. The purpose of this study was to assess the immunogenicity and safety of this liquid formulation. METHODS: In this multinational, open-label, single-arm study, patients (≥12 years) with moderate-to-severe allergic asthma were treated for 24 weeks with the liquid formulation of omalizumab (75 or 150 mg in a pre-filled syringe) at 2 or 4 week intervals. Immunogenicity was assessed by measurement of human anti-therapeutic antibody (ATA) levels. Safety was assessed by monitoring adverse events (AEs), haematology, blood chemistry, urine analysis and vital signs. RESULTS: A total of 155 patients were enrolled in the study. No patient had a confirmed positive ATA test result. Most frequent individual AEs were asthma (17.4%), sinusitis (17.4%) and upper respiratory tract infection (11.6%). Fourteen patients (9.0%) had serious AEs and there was one death (not treatment related). There were no cases of anaphylaxis according to Sampson criteria. Most patients remained within normal ranges for haematology and biochemistry laboratory variables. CONCLUSIONS: Omalizumab in pre-filled syringes was not associated with immunogenicity. This novel formulation, which does not require reconstitution, had a safety profile consistent with the lyophilised formulation. A limitation of this study is that efficacy of omalizumab in the treatment of asthma was not specifically addressed herein. Clinicaltrials.gov identifier: NCT00500539.