Allergen-specific Therapy Research Articles

STUDY OF THE COMMON WORMWOOD ALLERGOID

Background. The common wormwood pollen (lat. Artemisia absinthium) is one of the strongest allergens in central Russia, Europe and a number of other regions. It is a perennial herbaceous plant of the Asteraceae family, which easily adapts to various conditions, displacing other species. Allergen-specific therapy (ASIT) is currently considered the only effective method of treating allergies, since it directly affects the different phases of the disease, correcting the body's response to the allergen. The effectiveness of this therapy reaches 80-90% and shows a decrease in clinical manifestations and a decrease in the need for medications. Allergoids differ from allergens in that they retain their immunogenicity, while significantly reducing the likelihood of allergic reactions, which makes them safer for use in allergen-specific therapy. Allergoids produced in Russia by Microgen are created by polymerization using 1% formaldehyde. The use of glutaraldehyde speeds up this process to 24 hours, compared to 30 days when using formaldehyde alone. This method eliminates a highly toxic element from the production process. Aim. Preparation of an allergoid from wormwood pollen (lat. Artemisia absinthium) by treatment with glutaraldehyde. Materials and Methods. The purified allergen, isolated from pollen by degreasing and water-salt extraction, was dissolved in PBS pH 7.5 and polymerized in a 0.1% glutaraldehyde solution. Stabilization was carried out with a solution of sodium borohydride. Intraperitoneal immunization of CBA × C57Bl/6 (F1) mice with the obtained allergoid was carried out. Results. After assessing specific activity using a competitive enzyme-linked immunosorbent assay (ELISA), it was shown that the allergoid from wormwood pollen was significantly reduced in allergenicity compared to the parent allergen. In addition, the immunogenic activity of the resulting allergoid was confirmed in mice. Conclusions. During the work, the allergen of wormwood was obtained. The resulting allergen contains major and minor antigens of wormwood. An allergoid was obtained on its basis by polymerization with glutaraldehyde. The resulting allergoid has a large molecular weight and also has low allergenic activity in comparison with the original allergen, and also retains immunogenicity. In this regard, this allergoid can become the basis for obtaining new ASIT drugs.

Group 2 Innate Lymphoid Cells in Allergic Rhinitis.

Allergic rhinitis (AR), which presents symptoms like sneezing and a runny nose, is categorized as an upper respiratory condition of type 2. Recent progress in comprehending AR has revealed the significant role played by type 2 cytokines, specifically interleukin (IL)-13, IL-4, and IL-5. These cytokines are released by helper T cells 2 (Th2) and innate lymphoid cells (ILC2s). ILC2s have the ability to interact with various immune cells and are essential in promoting both type 2 immune response and tissue repair, contributing to normal homeostatic functions within the body. This article presents a summary of the latest advancements in comprehending the activity of ILC2s, with particular emphasis on their potential role involvement in AR. It explores how they collaborate with Th2 cells to exacerbate nasal inflammation and interact with regulatory T cells (Tregs) to counteract the suppressive role mediated by Tregs during allergic inflammation. The significance of ILC2s in allergen-specific therapy is highlighted. A comprehensive understanding of ILC2s biology establishes a robust foundation for unraveling the pathogenesis of AR and devising innovative therapeutic approaches for its management.

Virus-like Particles as Vaccines for Allergen-Specific Therapy: An Overview of Current Developments.

Immune engineering and modulation are the basis of a novel but powerful tool to treat immune diseases using virus-like particles (VLPs). VLPs are formed by the viral capsid without genetic material making them non-infective. However, they offer a wide variety of possibilities as antigen-presenting platforms, resulting in high immunogenicity and high efficacy in immune modulation, with low allergenicity. Both animal and plant viruses are being studied for use in the treatment of food allergies. These formulations are combined with adjuvants, T-stimulatory epitopes, TLR ligands, and other immune modulators to modulate or enhance the immune response toward the presented allergen. Here, the authors present an overview of VLP production systems, their immune modulation capabilities, and the applicability of actual VLP-based formulations targeting allergic diseases.

ФАКТОРЫ РИСКА УВЕЛИЧЕНИЯ ОБЪЕМА ЛЕКАРСТВЕННОЙ ТЕРАПИИ У ПЕДИАТРИЧЕСКИХ ПАЦИЕНТОВ С БРОНХИАЛЬНОЙ АСТМОЙ (ПО РЕЗУЛЬТАТАМ ДЕСЯТИЛЕТНЕГО ПРОСПЕКТИВНОГО НАБЛЮДЕНИЯ)

The study aims to determine the anamnestic, functional, and laboratory factors affecting the load of basic drug therapy in children with bronchial asthma during a ten-year regular dynamic monitoring of their height, body weight, spirometry data, the nature of the ongoing treatment of asthma, and the drug doses. An open, prospective monitoring trial included 131 patients, each of whom attended a hospital at least 20 times every 6 months. The data obtained was not used to correct the therapy method and regular medical check-up. By the end of the tenth year, 98 patients had demonstrated the following results: 57.1 % of children maintained a stable load of basic therapy, while the load of drug therapy was increased in 24.5 % of patients, and decreased in 18.4 % of them. The likelihood of a drug load reduction was statistically significantly reduced in patients with a body mass index greater than 90 weight percentile for 18 months or longer in comparison with patients who had never been overweight. Patients with the obstructive disorders detected with spirometry during two or more consecutive visits had a statistically significantly higher risk of drug therapy overload or a lower likelihood of its reduction in comparison with those without any external respiration malfunctions. The allergen-specific therapy made it possible to significantly lower the risk of drug overload and increase the possibility of its reduction. The allergen-specific immunotherapy, body weight management, and absence of obstructive disorders in spirometry all contribute to reducing the drug therapy load while maintaining a controlled course of the disease.

Celiac Disease: Disease Models in Understanding Pathogenesis and Search for Therapy

Celiac disease is a complex polygenic systemic disorder caused by dietary gluten exposure that selectively occurs in genetically susceptible people. The potential celiac disease is defined by the presence of celiac disease-specific antibodies and compatible human leukocyte antigen but without histological abnormalities in duodenal biopsies. At present, the only treatment is lifelong adherence to a gluten-free diet. Despite its effectiveness, the diet is difficult to maintain due to its cost, availability of gluten-free foods, and hidden gluten. The need to develop non-dietary treatment methods is widely recognized, but this is prevented by the absence of a pathophysiologically relevant preclinical model. Nonetheless, in vitro and in vivo models have made it possible to investigate the mechanisms of the disease and develop new treatment approaches: The use of foods with neutralized gluten, microbiota correction, cocktails of specific endoproteinase, polymer gluten binders, specific inhibitors of transglutaminases and inflammatory cytokines, and a vaccine based on allergen-specific therapy.

REACTION OF NASAL POLYPS IN ALLERGEN-SPECIFIC IMMUNOTHERAPY WITH FUNGAL ALLERGENS IN PATIENTS WITH NASAL POLYPS ON THE BACKGROUND OF FUNGAL SENSITIZATION

Fungal flora is one of the causes of inflammation, including nasal polyposis. Therefore, researches aimed at reducing the impact of fungal sensitization (FS) on the course of chronic rhinosinusitis with nasal polyps (CRSwNP) are relevant.
 The research included 90 patients with chronic rhinosinusitis with nasal polyps combined with fungal sensitization. The patients were divided into two groups — the first clinical group (G1) and the second clinical group (G2). Group G1 received allergen-specific immunotherapy (ASIT) according to the scheme. Group G2 received basic treatment according to the protocol № 181 of 24.03.2009 (“Protocol for providing medical care to patients with chronic sinusitis”). Indications for allergen-specific therapy were hyperreactivity to fungi (positive allergy history of FS), the presence of specific IgE antibodies to fungal allergens, positive skin tests with fungal allergens, and high levels of total IgE. The research aimed to evaluate the effect of allergen-specific therapy on nasal polyps in patients with CRSwNP on the background of fungal sensitization. The specific oral treatment was carried out in two phases: the first — cumulative or initial, and the second — maintaining, in which the maximum tolerated dose was reached by gradually increasing the allergen concentration. The first phase duration was about 2.5–3 months. In the second phase, which lasted up to 6 months, the patient received the maximum allowable dose of the allergen to achieve a state of persistent hyposensitization. The therapeutic allergen was administered in the morning, 30 minutes before meals. The right amount of drops were dosed per teaspoon from the bottle with the allergen.
 Treatment was initiated during the period of clinical remission. ASIT was performed with basic anti-inflammatory treatment. The treatment efficiency was evaluated after 3, 6, and 12 months of treatment.
 Evaluation of the clinical efficiency of allergen-specific immunotherapy was made on the 4-point scale, where excellent results (4 points) — complete remission of the disease during the follow-up period (6-12 months); good results (3 points) — exacerbation of the disease 1-2 times per year, in mild form and removed by expectant treatment; fair results (2 points) — the number of exacerbations did not decrease, poor results (1 point) treatment is stopped due to lack of effect or the patient's symptoms constantly worsen after the introduction of an allergen. The size and distribution of nasal polyps were assessed by the results of nasal endoscopy using the IV-grade scale: I degree - polyps are not visible on endoscopic examination but present on CT scan; II degree - polyps visible in the middle nasal passages; III degree - polyps visible outside the middle nasal passages; IV - degree – nasal polyps obturate the nasal cavity.
 Improvement of nasal endoscopy picture (the number of G1 patients diagnosed with stage III of nasal polyps after 12 months decreased by 11.1%), reducing the volume of basic therapy. Satisfactory treatment results were determined in 13.8% of patients, in whom the number of exacerbations did not decrease, but the general well-being became much better than before specific immunotherapy, which indicates a stable effect after the treatment.
 Conclusions. The results conclude that the use of ASIT treatment is pathogenetically justified and significantly improves the clinical condition and quality of life in patients with chronic rhinosinusitis with nasal polyps and fungal sensitization.
 The severity of the polypous process in G1 patients was 1.6 times lower compared to G2, which contributed to the positive clinical effect of treatment in 86.1% of patients.
 The conducted research has shown high efficacy, good tolerability, and safety of the non-invasive method of treatment (ASIT) in chronic rhinosinusitis with nasal polyps and fungal sensitization.

Covalent heterobivalent inhibitor effectively inhibits anaphylaxis to peanut allergen in a humanized mouse model

Abstract Peanut-induced allergy is an IgE-mediated type I hypersensitivity reaction that manifests symptoms ranging from local edema to life-threatening anaphylaxis. While there are treatments for symptoms in allergic patients resulting from allergen exposure, there are few preventive therapies other than avoidance and no allergen specific therapies. We have previously designed a covalent heterobivalent inhibitor (cHBI) that binds in an allergen-specific manner as a preventive for allergic reactions. Building on previous in vitro testing, in this report we have developed a humanized mouse model to test cHBI efficacy in vivo. Humanized mice (NSG-SCF/GM-CSF/IL-3) developed mature functional human mast cells in various tissues and developed robust anaphylactic reactions when passively sensitized with human IgE monoclonal antibodies specific for peanut allergen. We found that the allergic response is IgE dose-dependent and is mediated by human mast cells indicated by elevated tryptase serum levels and the upregulation of mast cell degranulation markers. Using the validated humanized mouse model, we showed that cHBI inhibited IgE-mediated anaphylaxis and human mast cell degranulation. We demonstrated that cHBI effectively inhibits anaphylaxis for up to 14 days, and cHBI inhibition is specific to peanut allergen. Importantly, cHBI rescued the mice from lethal anaphylactic response during oral peanut-induced anaphylaxis. These findings suggest that cHBI has the potential to be an effective preventative for peanut food allergy in patients.

Sublingual allergen-specific therapy in a child with diabetes mellitus

A description of a clinical case of a pediatric patient (boy, age 12 at the start of observation) with pollen allergy (allergic rhino-conjunctivitis to grass pollen) in combination with insulin-dependent diabetes mellitus is presented. Initiation criteria of allergen-specific immunotherapy (clear seasonal peak of exacerbations, high and concordant data of allergotesting In vivo and In vitro, progredient course of pollinosis clinical signs during years before allergen-specific immunotherapy was started) discussed in case of comorbid patient. Possible risks were analyzed and absence of diabetes mellitus as contraindication for immunotherapy stated. The patient underwent 2 pre-coseasonal courses of sublingual immunotherapy with grass pollen allergens in 2020 and 2021 with a pronounced positive effect. In the second year of treatment, remission of the disease was achieved: almost complete absence of hay fever symptoms in the flowering season of 2021, no progression of the disease, a significant decrease in the need for therapy to relieve symptoms. During the course of therapy, the patient did not show any deterioration in the course of diabetes mellitus, and the daily dose of insulin did not change. The patient is being monitored, and the third course of sublingual immunotherapy with grass pollen allergens is started.

Preparation and Characterization of a Glycyrrhizic Acid-Based Drug Delivery System for Allergen-Specific Immunotherapy.

The most effective method of treating allergic diseases, aimed not at relieving symptoms, but at eliminating the cause of the disease, is allergen-specific immunotherapy (AIT). To reduce the risk of side effects and improve the delivery of allergens to the mucosa, various delivery systems, such as liposomes, dendrimers, nanoparticles, etc., can be used. To date, there are data on the creation of delivery systems based on glycyrrhizic acid (GA) and its derivatives, but such a delivery system has not been used for allergen-specific therapy until now. It is also known that GA has an anti-inflammatory effect, shifts the balance towards Th1, and increases the number of Treg cells, meaning that it could potentially enhance the anti-allergic effect of AIT and reduce the risk of unwanted side effects. Thus, the study of the immunomodulatory effect of the supramolecular complexes (micelles) of GA with extracts of allergens holds promise for the development of new drugs for AIT.

CLINICAL SIGNIFICANCE OF IgG ANTIBODIES IN THE DIAGNOSIS OF ALLERGIC CONDITIONS AND CONTROL OF ALLERGEN-SPECIFIC IMMUNOTHERAPY. Review

Relevance. In recent years, there has been a significant increase in the number of allergic diseases among the population. In patients with allergic conditions in the presence of indications, allergists are increasingly prescribing allergen-specific immunotherapy. This necessitates the search for new accurate tools and markers for forecasting and evaluating its effectiveness. At present, methods of monitoring the effectiveness of allergen-specific immunotherapy are largely based on the assessment of the clinical condition of patients through questionnaires and provocative trials. Promising in this direction is the study of the role of IgG4 in the development of tolerance to allergens, and the mechanisms by which this protective function is realized. Particularly important are pathological reactions to food, which can be mediated not only by IgE, but also by IgG-associated circulating immune complexes. Therefore, it is important to study the role of IgG in the development of food intolerance and the possibility of using an elimination diet based on the identification of specific IgG to food in such patients.
 Objective: to summarize the literature and the results of own studies of IgG antibodies in the diagnosis of allergic conditions and control of allergen-specific immunotherapy.
 Methods. Search in international scientometric databases PubMed, Scopus, etc. by keywords. Search depth - 10 years (2011-2021). IgG determination was performed by FOX test (Food Xplorer Macro Array Diagnostics GmbH, Austria), enzyme linked immunosorbent assay (ELISA).
 Results. A review of the literature revealed studies that found an association between increases in IgG4 levels and a decrease in allergy in patients receiving allergen-specific therapy. Also, a significant number of studies attribute the important role of IgG in the development of food intolerance, in which a high-efficiency elimination diet based on excluded products to which specific IgG is detected.
 Conclusions. IgG is an antibody with unique biological properties, which plays an important role in the mechanisms of occurrence and course of a number of diseases, including those related to allergies. As a result, IgGs have great diagnostic potential. The existing problem of lack of objective diagnostic methods that would assess the effectiveness of allergen-specific immunotherapy in the early stages and predict the patient's condition in the future, could be solved by introducing the determination of IgG4 levels in general clinical practice. It is also important to determine food-specific IgG in patients with food intolerance, the content of which we determined using the FOX test. Various studies have established the effectiveness of a diet based on the elimination from the diet of foods to which specific IgG has been detected. Compared to the uncontrolled intake of symptomatic drugs and various unjustified dietary restrictions, this diet has significant therapeutic and economic benefits.

Treatment forms of house dust mites allergens intended for allergen-specific immunological therapy

BACKGROUND: The growth of allergic diseases dictates the necessity to develop new forms of therapeutic allergens since therapy with native water-salt extracts of allergens is unsafe and convenient. The risk of systemic side effects during allergen-specific immunotherapy sets the task for researchers to create modern therapeutic forms of allergens with high immunogenic and low allergenic activity. Our laboratory has been developing preparations for the diagnosis and treatment of house dust mites allergies for many years.
 AIMS: To create modern therapeutic forms of allergen preparations from house dust mites of the genus Dermatophagoides that are intended for allergen-specific immunotherapy
 MATERIALS AND METHODS: Physicochemical and immunobiological methods, such as electrophoresis in polyacrylamide gel, micropoint immunoblot, solid-phase enzyme-linked immunosorbent assay, and the reaction of binding inhibition of allergen-specific immunoglobulin E in the sera of patients were used to study the obtained preparations.
 RESULTS: A technology has been developed to obtain a granular dosage form of a mixed allergen from Dermatophagoides pteronyssinus and Dermatophagoides farinae mites for sublingual use. This treatment form has successfully passed preclinical tests, has a pronounced immunogenic activity, and reduced allergenicity, and is convenient for pediatric practice. Allergoids, which are chemically modified preparations, are obtained to reduce allergenicity and increase therapeutic allergen immunogenicity. A succinylated monomeric house dust mites allergoid Dermatophagoides pteronyssinus was created and studied with the National Research Center, Institute of Immunology Federal Medical-Biological Agency of Russia. The study of the immunobiological properties of the obtained preparation showed that the monomeric allergoid has increased immunogenic and decreased allergenic activity contrary to the native water-salt extract.
 CONCLUSIONS: The created forms of mite allergens can be used to treat patients who are sensitized to house dust mites of the genus Dermatophagoides after clinical trials.

Development of nasal allergen challenge with cockroach in children with asthma.

Nasal allergen challenge (NAC) could be a means to assess indication and/or an outcome of allergen-specific therapies, particularly for perennial allergens. NACs are not commonly conducted in children with asthma, and cockroach NACs are not well established. This study's objective was to identify a range of German cockroach extract doses that induce nasal symptoms and to assess the safety of cockroach NAC in children with asthma. Ten adults (18-37years) followed by 25 children (8-14years) with well-controlled, persistent asthma and cockroach sensitization underwent NAC with diluent followed by up to 8 escalating doses of cockroach extract (0.00381-11.9µg/mL Bla g 1). NAC outcome was determined by Total Nasal Symptom Score (TNSS) and/or sneeze score. Cockroach allergen-induced T-cell activation and IL-5 production were measured in peripheral blood mononuclear cells. 67% (6/9) of adults and 68% (17/25) of children had a positive NAC at a median response dose of 0.120µg/mL [IQR 0.0380-0.379µg/mL] of Bla g 1. Additionally, three children responded to diluent alone and did not receive any cockroach extract. Overall, 32% (11/34) were positive with sneezes alone, 15% (5/34) with TNSS alone, and 21% (7/34) with both criteria. At baseline, NAC responders had higher cockroach-specific IgE (P=.03), lower cockroach-specific IgG/IgE ratios (children, P=.002), and increased cockroach-specific IL-5-producing T lymphocytes (P=.045). The NAC was well tolerated. We report the methodology of NAC development for children with persistent asthma and cockroach sensitization. This NAC could be considered a tool to confirm clinically relevant sensitization and to assess responses in therapeutic studies.

Dynamics of basophil reactivity in the patients with allergic rhinitis on the background of allergen-specific immunotherapy

BACKGROUND: Allergen-specific immunotherapy (ASIT) helps to reduce spontaneous and to induce basophil reactivity, which is one of the major mechanisms of its effectiveness. A number of studies, though, have not confirmed the informative value of the basophil activation test (BAT), in case of ASIT, with house dust mites, meadow grass pollen, and wasp venom. BAT outcomes are likely to be influenced by the properties of the sensitizing allergen, the duration of ASIT, and the BAT markers that are used.
 AIMS: To evaluate the basophils reactivity in the patients sensitized to weed pollen and treated with allergen-specific therapy.
 MATERIALS AND METHODS: The study involved 60 patients (aged 1655) with allergic rhinitis sensitized to weed pollen. The diagnosis was based on the skin test outcomes as well as on identifying specific antibodies to major allergens of ragweed, wormwood, timothy, and birch. The pre-seasonal ASIT involved water-salted extracts of pollen allergens during 2 years. Clinical symptoms and the immunotherapy effectiveness were evaluated 6 and 18 months after the ASIT started. BATs were made before the treatment, after the first and second courses of pre-seasonal ASIT, which corresponded to zero, the 3rd and the 15th months of the treatment. The activated basophils were identified based on the CRTH2pos CD203brightCD3neg phenotype.
 RESULTS: The first treatment course was completed by 52 patients, while the second one by 43 patients. A statistically significant decrease in spontaneous basophil reactivity was detected only after the second course of ASIT. The decrease in the allergen-induced basophil activation was identified in 67.4% of the samples obtained after the first ASIT course, and in 67.6% of samples taken after the second immunotherapy course. A decrease in the BAT stimulation index (BAT SI) was identified mainly in the patients featuring positive treatment outcomes.
 CONCLUSIONS: ASIT influences on the basophil reactivity indicators in the patients sensitized to weed pollen. The basophil activation test may be considered as a potential predictor of ASIT effectiveness.

A novel allergen-specific therapy with CD40-silenced B cells and dendritic cells

Summary CD40-silenced B cells, induced by siRNA, inhibited allergic responses and symptoms antigen-specifically even after allergic rhinitis had been established. CD40-silenced B cells and CD40-silenced dendritic cells also have independent mechanisms with a synergic effect.

Immunological Mechanisms in Allergic Diseases and Allergen Tolerance: The Role of Treg Cells.

The immune system regulates itself to establish an appropriate immune response to potentially harmful pathogens while tolerating harmless environmental antigens and self-antigens. A central role in this balance is played by regulatory T cells (Tregs) through various ways of actions. By means of molecule secretion and cell-cell contact mechanisms, Tregs may have the capacity to modulate effector T cells and suppress the action of proinflammatory cytokines across a broad range of cell types. As a result, abnormal regulatory T cell function has been pointed as a main cause in the development of allergic diseases, a major public health problem in industrialized countries, with a high socioeconomic impact. This prevalence and impact have created an international interest in improving the allergy diagnosis and therapy. Additionally, research has sought to gain a better understanding of the molecular mechanisms underlining this kind of disease, in order to a better management. At this respect, the role of Treg cells is one of the most promising areas of research, mainly because of their potential use as new immunotherapeutical approaches. Therefore, the aim of this review is to update the existing knowledge of the role of Tregs in this pathology deepening in their implication in allergen-specific therapy (AIT).

Antigen-specific regulatory T-cell responses against aeroantigens and their role in allergy.

The mucosal immune system of the respiratory tract is specialized to continuously monitor the external environment and to protect against invading pathogens, while maintaining tolerance to innocuous inhaled particles. Allergies result from a loss of tolerance against harmless antigens characterized by formation of allergen-specific Th2 cells and IgE. Tolerance is often described as a balance between harmful Th2 cells and various types of protective "regulatory" T cells. However, the identity of the protective T cells in healthy vs. allergic individuals or following successful allergen-specific therapy is controversially discussed. Recent technological progress enabling the identification of antigen-specific effector and regulatory T cells has significantly contributed to our understanding of tolerance. Here we discuss the experimental evidence for the various tolerance mechanisms described. We try to integrate the partially contradictory data into a new model proposing different mechanism of tolerance depending on the quality and quantity of the antigens as well as the way of antigen exposure. Understanding the basis of tolerance is essential for the rational design of novel and more efficient immunotherapies.

Application of bacterial therapeutic vaccine Immunovac-VP4 in the treatment of pollinosis.

The aim of the study was to study the effectiveness of the complex use of bacterial therapeutic vaccine Immunovac-VP4 and allergen-specific immune therapy (ASIT) in pollinosis in children and adults. Bacterial therapeutic vaccine Immunovac-VP4 was used annually, nasal and oral administration in patients before the course of ASIT standardized aqueous-salt solutions of allergens. The therapeutic application of bacterial vaccines, Immunoac-ВП4 before the course ASIT has helped to reduce the frequency of acute respiratory infections in 8,5 times in comparison with the control group. Clinical efficacy of complex treatment according to the results of the survey of patients in 7 years after the start of therapy was 90%. There was a significant decrease In IgG4 to causally significant allergens, General immnunoglobulin E (IgE) and a tendency to decrease IgE. The use of bacterial therapeutic vaccine Immunovac-VP4, which is a natural ligand of toll-like receptors in combination with ASIT, seems to be an effective and promising direction in the treatment of allergic diseases.

A novel allergen-specific therapy with regulatory T cells induced by CD40-silenced dendritic cells.

We previously reported that dendritic cells (DCs) transfected with CD40 siRNA and pulsed by ovalbumin (OVA) (CD40-silenced OVA DCs) inhibited allergic responses through facilitation of regulatory T cells (Tregs). However, to our knowledge, no prior study has examined allergen-specific therapy by administration of siRNA-induced Tregs for the control of allergy. We aimed to investigate the effect of Tregs induced in vitro on allergic responses and symptoms in vivo. Mice were treated with Tregs (OVA DCs-induced Tregs) induced by CD40-silenced OVA DCs or Tregs (nonantigen DCs-induced Tregs) induced by DCs transfected with CD40 siRNA and pulsed with no antigen, and the effects of these Tregs on allergic responses were estimated. Administration of nonantigen DCs-induced Tregs prevented not only OVA-induced allergy but also keyhole limpet hemocyanin-induced allergy. Administration of OVA DCs-induced Tregs significantly reduced the number of sneezes and nasal rubbing movements, eosinophilia in the nasal mucosa, and the level of OVA-specific IgE in mice with OVA-induced allergy, compared with CD40-silenced nonantigen DC-induced Tregs in numbers 20 times greater, even in mice with established allergic rhinitis. Furthermore, Tregs induced by CD40-silneced DCs pulsed with Cry j 1, a major allergen of Japanese cedar pollen, inhibited Japanese cedar-induced allergy. This study shows for the first time that both antigen-independent Tregs and antigen-specific Tregs can be induced by siRNA, and that therapy with siRNA-induced Tregs inhibits allergic responses and symptoms. It also shows that antigen-specific Tregs have more potent effects in inhibiting allergic responses than antigen-nonspecific Tregs.

Blocking antibodies induced by immunization with a hypoallergenic parvalbumin mutant reduce allergic symptoms in a mouse model of fish allergy

BackgroundFish is a frequent elicitor of severe IgE-mediated allergic reactions. Beside avoidance, there is currently no allergen-specific therapy available. Hypoallergenic variants of the major fish allergen, parvalbumin, for specific immunotherapy based on mutation of the 2 calcium-binding sites have been developed.ObjectivesThis study sought to establish a mouse model of fish allergy resembling human disease and to investigate whether mouse and rabbit IgG antibodies induced by immunization with a hypoallergenic mutant of the major carp allergen protect against allergic symptoms in sensitized mice.MethodsC3H/HeJ mice were sensitized with recombinant wildtype Cyp c 1 or carp extract by intragastric gavage. Antibody, cellular immune responses, and epitope specificity in sensitized mice were investigated by ELISA, rat basophil leukemia assay, T-cell proliferation experiments using recombinant wildtype Cyp c 1, and overlapping peptides spanning the Cyp c 1 sequence. Anti-hypoallergenic Cyp c 1 mutant mouse and rabbit sera were tested for their ability to inhibit IgE recognition of Cyp c 1, Cyp c 1–specific basophil degranulation, and Cyp c 1–induced allergic symptoms in the mouse model.ResultsA mouse model of fish allergy mimicking human disease regarding IgE epitope recognition and symptoms as close as possible was established. Administration of antisera generated in mice and rabbits by immunization with a hypoallergenic Cyp c 1 mutant inhibited IgE binding to Cyp c 1, Cyp c 1–induced basophil degranulation, and allergic symptoms caused by allergen challenge in sensitized mice.ConclusionsAntibodies induced by immunization with a hypoallergenic Cyp c 1 mutant protect against allergic reactions in a murine model of fish allergy.

Current issues on sublingual allergen-specific immunotherapy in children with asthma and allergic rhinitis

In 1993 the European Academy of Allergy and Clinical Immunology was the first official organization to recognize that sublingual administration could be “promising route” for allergic desensitization. A few years later, the World Health Organization recommended this therapy as “a viable alternative to the injection route in adults.” The first meta-analysis showed sublingual allergen specific immunotherapy (SLIT) effectiveness for allergic rhinitis and another study showed SLIT can actually help prevent the development of asthma both in adults and in children. The main goal of this review article is to present insight into the most up-to-date understanding of the clinical efficacy and safety of immunotherapy in the treatment of pediatric patients with allergic rhinitis and asthma. A literature review was performed on PubMed from 1990 to 2015 using the terms “asthma,” “allergic rhinitis,” “children,” “allergen specific immune therapy.” Evaluating data from double-blind placebo-controlled randomized clinical trials (DB-PC-RCTs), the clinical efficacy (assessed as the reduction of symptom score and the need of rescue medicament) of SLIT for allergic rhinitis and allergic asthma, has been confirmed in various meta-analysis Outcomes such as rhinoconjunctivitis score and medication scores, combined scores, quality of life, days with severe symptoms, immunological endpoints, and safety parameters were all improved in the SLIT-tablet compared with placebo group. SLIT safety has been already proven in many DB-PC-RCTs and real-life settings. In accordance with all of the above mentioned, the goals for future trials and studies are the development of comprehensive guidelines for clinical practice on immunotherapy, embracing all the different potential participants. The importance of allergen immunotherapy is of special relevance in the pediatric age, when the plasticity and modulability of the immune system are maximal, and when preventative effects can be reasonably expected.