Oral administration of a T cell epitope inhibits symptoms and reactions of allergic rhinitis in Japanese cedar pollen allergen-sensitized mice

Next-Generation Allergen-Specific Immunotherapy for Japanese Cedar Pollinosis Using Molecular Approaches

Japanese cedar (JC) pollinosis is the most major IgE-mediated type I allergic disease in Japan. Allergen-specific immunotherapy is the only curative treatment for allergic diseases. Subcutaneous immunotherapy and sublingual immunotherapy have been introduced in Japan for JC pollinosis, but do not avoid some adverse side effects, because the natural allergens used as tolerogens cross-link with specific IgE types on mast cells and basophils. To make immunotherapy for JC pollinosis safer, more effective and convenient, rice-based oral allergy vaccines using hybrid peptides composed of multiple T-cell epitopes or recombinant deconstructed hypoallergenic derivatives derived from major allergens — Cry j 1 and Cry j 2 — have been developed and their efficacy and safety evaluated by oral administration of transgenic rice seeds. Furthermore, recombinant modified JC allergens conjugated with various immunomodulatory molecules and DNA-based vaccines have been created and their efficacy assessed.

Solid-in-Oil Nanodispersions for Transcutaneous Immunotherapy of Japanese Cedar Pollinosis

Japanese cedar pollinosis (JCP) is a common affliction caused by an allergic reaction to cedar pollen and is considered a disease of national importance in Japan. Antigen-specific immunotherapy (AIT) is the only available curative treatment for JCP. However, low compliance and persistence have been reported among patients subcutaneously or sublingually administered AIT comprising a conventional antigen derived from a pollen extract. To address these issues, many research studies have focused on developing a safer, simpler, and more effective AIT for JCP. Here, we review the novel antigens that have been developed for JCP AIT, discuss their different administration routes, and present the effects of anti-allergy treatment. Then, we describe a new form of AIT called transcutaneous immunotherapy (TCIT) and its solid-in-oil (S/O) nanodispersion formulation, which is a promising antigen delivery system. Finally, we discuss the applications of S/O nanodispersions for JCP TCIT. In this context, we predict that TCIT delivery by using a S/O nanodispersion loaded with novel antigens may offer an easier, safer, and more effective treatment option for JCP patients.

Next generation immunotherapy for tree pollen allergies

Tree pollen induced allergies are one of the major medical and public health burdens in the industrialized world. Allergen-Specific Immunotherapy (AIT) through subcutaneous injection or sublingual delivery is the only approved therapy with curative potential to pollen induced allergies. AIT often is associated with severe side effects and requires long-term treatment. Safer, more effective and convenient allergen specific immunotherapies remain an unmet need. In this review article, we discuss the current progress in applying protein and peptide-based approaches and DNA vaccines to the clinical challenges posed by tree pollen allergies through the lens of preclinical animal models and clinical trials, with an emphasis on the birch and Japanese red cedar pollen induced allergies.

Role of Prostaglandin D2 and DP1 Receptor on Japanese Cedar Pollen-Induced Allergic Rhinitis in Mice

Although we previously demonstrated the contribution of the DP1receptor in nasal obstruction using animals sensitized with ovalbumin in the presence of adjuvant, the contribution of the DP1receptor in sneezing is unclear. Here, we developed a mouse model of Japanese cedar (JC:Cryptomeria japonica) pollinosis to evaluate the symptoms of sneezing. To achieve this, we used JC pollen crude extract in the absence of adjuvant to sensitize mice to develop a model closer to the pathophysiology of human JC pollinosis. The immunologic and pharmacologic features of this model are highly similar to those observed in JC pollinosis in humans. Using this model, we found that DP1receptor antagonists suppressed JC pollen extract-induced sneezing and that a DP1receptor agonist induced sneezing. Moreover, JC pollen extract-induced sneezing was diminished in DP1receptor knockout mice. In conclusion, we developed a novel mouse model of allergic rhinitis that closely mimics human JC pollinosis. A strong contribution of DP1receptor signaling to sneezing was demonstrated using this model, suggesting that DP1receptor antagonists could suppress sneezing and nasal obstruction, and therefore these agents could be a new therapeutic option for allergic rhinitis.

Establishment and characterization of a novel murine model for pollen allergy

Although there have been many studies revealing the mechanism and establishing the therapeutical method for allergic rhinitis, no suitable animal models for allergic rhinitis, especially for pollen allergy, are currently available. We therefore aimed in this study to develop a murine model producing IgE in response to an inhaled antigen without using any adjuvants. Ovalbumin (OVA)-specific T cell receptor transgenic mice (DO11.10) inhaled an OVA solution for one h, twice a week, for six weeks. The resulting increase of OVA-specific IgE in the serum was observed depending on the times of inhalation. Spleen cells from mice that had inhaled the antigen produced more IL-4 and less IFN-γ than those from the control mice in vitro. These results indicate that inhaled antigen enhanced the Th2-type responses and induced IgE production in a T cell-mediated manner. Our findings would contribute to studies on prevention and treatment of pollen allergy.

Therapeutic effects of β1, 4 mannobiose in a Balb/c mouse model of intranasally-induced pollen allergy

BACKGROUND

Nutritional prebiotic supplementation represents an attractive approach for interventions of allergy. In this study, the potential therapeutic effect of β-1, 4 mannobiose (MNB) in a murine model of cedar pollinosis was investigated.

METHODS

Groups of Balb/c mice were intranasally sensitized to Japanese cedar pollen extract, and subsequently administered with low or high dose MNB. Both intraperitoneal and intranasal challenges were performed to monitor for clinical signs. Frequency of sneezing was recorded. Serum, spleen and Peyer's patches were collected for various biomarker analyses. Anti-allergic activity of MNB using RBL-2H3 cells was also evaluated.

RESULTS

Significant decrease in sneezing frequency, histamine, interleukin (IL)-4 and IL-17A and increase in TGF-β and IL-10 concentration were exhibited by the MNB-treated mice. However, Cry j1 and Cry j 2-specific IgE activity remained unaltered. The high dose MNB treatment increased total IgA activity and IL-10, TGF-β and FoxP3 and decreased IL-4, IL-17A, and RORγT mRNA expression. Inhibition of activation of RBL-2H3 cells was observed via decrease in histamine, intracellular Ca2+ concentration, and FcεRI mRNA expression.

CONCLUSIONS

We demonstrated the immunomodulatory effects of MNB and conclude that MNB is a potential therapeutic molecular nutritional supplement candidate for treatment of pollen allergy.

Prophylaxis of intranasally induced pollen allergy in a BALB/C mouse model using a potential prebiotic β-1, 4 mannobiose

BACKGROUND

Dietary supplementation with unique prebiotic nondigestible carbohydrates has been shown to suppress allergy. In the present study, the prophylactic efficacy of a disaccharide β-1, 4 mannobiose (MNB) in a BALB/C mouse model of intranasally-induced pollen allergy was characterized.

METHODS

Balb/c mice were pretreated with MNB orally and sensitized with pollen extract intraperitoneally and intranasally and challenged with histamine and crude pollen extract. Outcomes were measured as clinical signs, antibody isotypes, cytokine gene and protein expression patterns.

RESULTS

The MNB-treated mice had lower sneezing frequency as compared to the positive control mice (P < 0.05). The low dose MNB-treated mice had less histamine (P < 0.05). However, the Cry j1 and Cry j 2-specific IgE, IgG, IgG1 and IgG2a antibody activity did not differ between groups (P > 0.05). The MNB-treated mice had increased IFN-γ (P < 0.05), and decreased IL-4 (P < 0.05). Mice in the high dose group had increased IL-10 (P < 0.05). However, TGF-β and IL-17 concentration did not differ between groups (P > 0.05). Both total and Cry j1 and Cry j 2-specific IgA were increased in the high dose group. Real-time RT-PCR analysis indicated that IL-4 and IL-17 mRNA expression were lower in MNB-treated mice (P < 0.05).

CONCLUSIONS

This work provides insights into using MNB as a potential prebiotic immunomodulator via decreased clinical signs, improved type1/type 2 balance, and IgA production, thus validating the potential use of MNB as a prophylactic prebiotic candidate to attenuate allergic response.

Oral immunotherapy with transgenic rice seed containing destructed Japanese cedar pollen allergens, Cry j 1 and Cry j 2, against Japanese cedar pollinosis

Transgenic rice accumulating the modified major Japanese cedar pollen allergens, Cryptomeria japonica 1 (Cry j 1) and Cryptomeria japonica 2 (Cry j 2), which were deconstructed by fragmentation and shuffling, respectively, in the edible part of the seed was generated by transformation of a good-tasting rice variety, 'Koshihikari'. These modified cedar pollen antigens were deposited in ER-derived protein bodies (PB-I), which are suitable for delivery to the mucosal immune system in gut-associated lymphoid tissue when orally administered because antigens bioencapsulated in PB-I are resistant against hydrolysis by intestinal enzymes and harsh environments. Mice fed transgenic seeds daily for three weeks and then challenged with crude cedar pollen allergen showed marked suppression of allergen-specific CD4(+) T-cell proliferation, IgE and IgG levels compared with mice fed nontransgenic rice seeds. As clinical symptoms of pollinosis, sneezing frequency and infiltration of inflammatory cells such as eosinophils and neutrophils were also significantly reduced in the nasal tissue. These results imply that oral administration of transgenic rice seeds containing the structurally disrupted Cry j 1 and Cry j 2 antigens, serving as universal antigens, is a promising approach for specific immunoprophylaxis against Japanese cedar pollinosis.

The effect of nano-silver on allergic rhinitis model in mice

OBJECTIVES

Silver has long been known as a strong antimicrobial and disinfectant. Several types of nano-silver coated products have been developed. However, the antimicrobial and disinfectant characteristics of nano-silver have not been well studied. The aim of this study was to investigate the effect of nano-silver on allergic inflammation in a mouse model.

METHODS

Female BALB/C mice were sensitized by intraperitoneal injection of ovalbumin (OVA) and aluminium hydroxide on days 0, 7, 14, and 21. Mice were challenged with intranasal instillation of OVA. Nano-silver was also administered nasally prior to intranasal instillation of OVA. Severity of allergic rhinitis was assessed according to nasal symptoms, serum OVA-specific IgE level, interleukin (IL)-4, IL-10, and interferon (INF)-γ levels in nasal lavage fluid. Hematoxylin-eosin stain and periodic acid-Schiff stain were performed for evaluation of histological change.

RESULTS

Nano-silver attenuated manifestation of nasal symptoms in sensitized mice and inhibited production of OVA-specific IgE, IL-4, and IL-10, however, it had no effect on INF-γ level. In addition, the degree of inflammatory cell infiltration and goblet cell hyperplasia was attenuated by nano-silver.

CONCLUSION

These results suggest that nano-silver may effectively reduce allergic inflammation in a mouse model of allergic rhinitis. Through its properties as an anti-inflammatory agent, nano-silver may be a useful therapeutic strategy.

Inducible nitric oxide synthase plays important roles in allergic reactions of pollinosis in mice sensitized with pollen allergy

To elucidate the possible involvement of nitric oxide (NO) derived from inducible NO-synthase (iNOS) in the pathogenesis of patients with allergic rhinitis, we analyzed changes in the frequency of sneezing, plasma levels of NO metabolites, α-melanocyte-stimulating hormone (MSH) and immunoglobulin E and tracheal expression of IgA and mast cell tryptase in control and iNOS^−/− mice. Eight-week-old control and iNOS^−/− male C57BL/6j mice were sensitized with Cry j I antigen. After the last intranasal challenge of antigen, changes in the frequency of sneezing and plasma levels of IgE, α-MSH and NO metabolites and tracheal expression of iNOS, IgA and mast cell tryptase were analyzed by ELISA and immunohistochemistry using specific antibodies. The sensitization of mice with Cry j I antigen increased plasma levels of NO metabolites, α-MSH and IgE and tracheal expression of iNOS, IgA and mast cell tryptase in control not but in iNOS^−/− mice. Administration of N^G-nitro-L-arginine methyl ester strongly inhibited all these changes occurred in control mice. These results indicate that the symptom of pollinosis including sneezing is enhanced by iNOS derived NO through activation of α-MSH-receptor containing mast cells enriched with tryptase.

Oral immunotherapy with immunodominant T-cell epitope peptides alleviates allergic reactions in a Balb/c mouse model of egg allergy

BACKGROUND

  Allergen-specific T-cell epitopes are obvious targets for immunotherapeutic interventions in allergic disease. T-cell epitope peptides given orally may provide a practical way of inducing tolerance and preventing allergy.

OBJECTIVE

  This study investigates oral immunotherapy (OIT) with T-cell epitope peptides of the dominant egg-white allergen ovomucoid (Ovm) in a Balb/c mouse model of egg allergy.

METHODS

  Groups of mice were orally sensitized to Ovm and subsequently administered Ovm T-cell epitopes [single peptide 157-171 (SP) or multiple peptide (157-171)(3) (MP)], followed by oral challenge with Ovm. Outcomes post oral challenge were measured as clinical signs, serum histamine, antibody activity (IgG, IgE, IgG1, IgG2, IgA), cytokines (IL-4, IFN-γ, IL-12p70, IL-10, TGF-β, and IL-17), and T regulatory cells (Tregs).

RESULTS

  Clinical signs were less frequent in both SP and MP groups (P ≤ 0.05). Specific IgE was less and IgA was more in both groups; however, SP-treated mice had less histamine and IgG1 and more IgG2-related antibodies indicating a bias toward the type-1 response (P ≤ 0.05). Concentration of type-2 cytokine interleukin-4 (IL-4) was significantly less in both groups and IL-12p70 and IL-10 were more in SP-treated mice (P ≤ 0.001). Interferon-γ, IL-17, and TGF-β did not differ significantly. There was significant increase in the percentage of CD4+FOXP3+ and CD4+CD25+ cells in the SP group, indicating the significant role of Tregs in immune regulation.

CONCLUSION

  In summary, we demonstrated that OIT with SP and MP comprising the immunodominant regions of Ovm was safe and significantly reduced subsequent frequency of allergy to Ovm, and validated potential use of Ovm T-cell epitope as an immunoregulator.

Characterization of pollen dispersion in the neighborhood of Tokyo, Japan in the spring of 2005 and 2006

The behavior of Japanese cedar (Cryptomeria japonica) and Japanese cypress (Chamaecyparis obtusa) pollens in an urban area was examined through the measurements of the dispersion characteristics at the various sampling locations in both outdoor and indoor environments. Airborne pollens were counted continuously for three months during the Japanese cedar pollen and Japanese cypress seasons in 2005 and 2006 by the use of Durham's pollen trap method in and around Tokyo, Japan. The dispersion of pollens at the rooftop of Kyoritsu Women's University was observed to be at extremely high levels in 2005 compared with previously reported results during the past two decades. As for Japanese cedar pollen, the maximum level was observed as 440 counts cm(-2) day(-1) on 18 March 2005. Japanese cypress pollen dispersed in that area in the latter period was compared with the Japanese cedar pollen dispersions. The maximum dispersion level was observed to be 351 counts cm(-2) day(-1) on 7 April 2005. Total accumulated dispersions of Japanese cedar and Japanese cypress pollens were 5,552 and 1,552 counts cm(-2) for the three months (Feb., Mar. and Apr.) in 2005, respectively. However, the dispersion of both pollens in 2006 was very low. The total accumulated dispersions of Japanese cedar and Japanese cypress pollens were 421 and 98 counts cm(-2) for three months (Feb., Mar. and Apr.) in 2006, respectively. Moreover, the pollen deposition on a walking person in an urban area showed that the pollen counts on feet were observed to be extremely high compared with the ones on the shoulder, back and legs. These findings suggested that pollen fell on the surface of the paved road at first, rebounded to the ambient air and was deposited on the residents again. Furthermore, the regional distribution of the total pollen dispersion in the South Kanto area was characterized on 15-16 March 2005 and on 14-15 March 2006. Although the pollen levels in 2005 were much higher than in 2006, it was commonly observed that higher pollen counts existed in the outlying areas. That is, the pollen counts in an urban area were confirmed to be at a lower level. As for the indoor dispersion of pollens, two cases were evaluated. At the lobby of the main building of Kyoritsu Women's University, the averaged ratio of the indoor to the outdoor pollen count is 4.1%. Another case was at the hospital building of a medical school. The pollen dispersion in the indoor environment was also observed to be low. It was concluded that the indoor pollen would be mainly carried from the outer environment by the movement of air.

CRTH2 plays an essential role in the pathophysiology of Cry j 1-induced pollinosis in mice

PGD(2) is the major prostanoid produced during the acute phase of allergic reactions. Two PGD(2) receptors have been isolated, DP and CRTH2 (chemoattractant receptor-homologous molecule expressed on Th2 cells), but whether they participate in the pathophysiology of allergic diseases remains unclear. We investigated the role of CRTH2 in the initiation of allergic rhinitis in mice. First, we developed a novel murine model of pollinosis, a type of seasonal allergic rhinitis. Additionally, pathophysiological differences in the pollinosis were compared between wild-type and CRTH2 gene-deficient mice. An effect of treatment with ramatroban, a CRTH2/T-prostanoid receptor dual antagonist, was also determined. Repeated intranasal sensitization with Cry j 1, the major allergen of Cryptomeria japonica pollen, in the absence of adjuvants significantly exacerbated nasal hyperresponsive symptoms, Cry j 1-specific IgE and IgG1 production, nasal eosinophilia, and Cry j 1-induced in vitro production of IL-4 and IL-5 by submandibular lymph node cells. Additionally, CRTH2 mRNA in nasal mucosa was significantly elevated in Cry j 1-sensitized mice. Following repeated intranasal sensitization with Cry j 1, CRTH2 gene-deficient mice had significantly weaker Cry j 1-specific IgE/IgG1 production, nasal eosinophilia, and IL-4 production by submandibular lymph node cells than did wild-type mice. Similar results were found in mice treated with ramatroban. These results suggest that the PGD(2)-CRTH2 interaction is elevated following sensitization and plays a proinflammatory role in the pathophysiology of allergic rhinitis, especially pollinosis in mice.

Effect of Cry-consensus peptide, a novel recombinant peptide for immunotherapy of Japanese cedar pollinosis, on an experimental allergic rhinitis model in B10.S mice

BACKGROUND

We are developing an immunotherapeutic peptide, Cry-consensus peptide, for Japanese cedar pollinosis. Cry-consensus peptide is a recombinant polypeptide containing six major human T-cell epitopes derived from both Cry j 1 and Cry j 2, two major allergens of Japanese cedar pollen. We examined the effect of Cry-consensus peptide on an allergic rhinitis model in B10.S mice, which have one common T-cell epitope in the Cry-consensus peptide.

METHODS

B10.S mice were sensitized with Cry j 1/alum, then the Cry-consensus peptide was administered subcutaneously once a week for 5 weeks from the last sensitization. Histamine was dropped in both nostrils (10 microL per nostril) of each mouse on the day before continuous intranasal instillation of Cry j 1. Soon after the final challenge with Cry j 1, the mice were observed for 5 minutes for the resulting number of sneezes. In addition, serum levels of Cry j 1-specific IgE and IgG2a antibody, eosinophil infiltration in nasal tissue, and Cry j 1-specific cytokine production from splenocytes were evaluated.

RESULTS

Cry-consensus peptide markedly inhibited Cry j 1-induced sneezes, eosinophil infiltration, and eosinophil peroxidase (EPO) activity in nasal tissue. Cry-consensus peptide inhibited the production of anti-Cry j 1 IgE (Th2-mediated) and significantly enhanced anti-Cry j 1 IgG2a (Th1-mediated). In cytokine production from splenocytes, Cry-consensus peptide significantly decreased in IL-4/IFN-gamma and IL-5/IFN-gamma ratios.

CONCLUSIONS

It was concluded that Cry-consensus peptide effectively controlled allergic responses, which results from shifting from a Th2-dominated to a Th1-dominated immune response.

Establishment of an allergic rhinitis model in mice for the evaluation of nasal symptoms

The purpose of our study was to establish a new model of allergic rhinitis in mice, eliciting symptoms such as sneezing, infiltration of eosinophils into the nasal mucosa, and antigen-specific IgE production. One of the major human T-cell epitopes in Cry j 1, an allergen of Japanese cedar pollen, is also a major murine T-cell epitope in B10.S mice. Thus we tried to establish an allergic rhinitis model in B10.S mice with Cry j 1 as the antigen. We sensitized B10.S mice subcutaneously with Cry j 1/alum three times at intervals of 1 week. Five weeks after the final sensitization, we challenged the mice by instilling Cry j 1 intranasally from the day after intranasal histamine pretreatment. Soon after, we counted the number of sneezes. We then evaluated the infiltration of eosinophils into the nasal tissues and also measured the serum levels of antigen-specific IgE antibody. In addition, we confirmed the effects of ketotifen fumarate and dexamethasone hydrochloride on these animals. In Cry j 1-sensitized B10.S mice, sneezes, eosinophil peroxidase (EPO) activity in nasal tissues, and Cry j 1-specific IgE clearly increased after intranasal histamine pretreatment and 5 days of continuous intranasal Cry j 1 challenge. Both ketotifen and dexamethasone inhibited the increase in sneezing, and dexamethasone also inhibited EPO activity and Cry j 1-specific IgE. Thus we succeeded in establishing a new model of allergic rhinitis in Cry j 1-sensitized B10.S mice, which exhibited sneezing, eosinophil infiltration into the nasal mucosa, and Cry j 1-specific IgE production.

Biological assay using T cell response for Cry-consensus peptide designed for the peptide-based immunotherapy of Japanese cedar pollinosis

INTRODUCTION

Cry-consensus peptide is a linearly linked peptide of T-cell epitopes for the management of Japanese cedar (JC) pollinosis and is expected to become a new drug for immunotherapy. However, the mechanism of T-cell epitopes in allergic diseases is not well understood, and thus, a simple in vitro procedure for evaluation of its biological activity is desired.

METHODS

Peripheral blood mononuclear cells (PBMC) were isolated from 27 JC pollinosis patients and 10 healthy subjects, and cultured in vitro for 4 days in the presence of Cry-consensus peptide and (3)H-thymidine. The relationship between growth stimulation (stimulation index; SI) and antigen-specific IgE levels in serum was also investigated in JC pollinosis patients. Moreover, to confirm the importance of the primary sequence in Cry-consensus peptide, heat-treated Cry-consensus peptide and a mixture of the amino acids of which Cry-consensus peptide is composed, and their (3)H-thymidine uptake was compared with Cry-consensus peptide. Finally, whether Cry-consensus peptide stimulates PBMCs from healthy subjects was investigated.

RESULTS

The mean SI of JC patients showed a good correlation with Cry-consensus peptide concentration in the culture medium; however, the SI was independent of the anti-Cry j 1 IgE level. Heat-denatured Cry-consensus peptide retained a PBMC proliferation stimulatory effect comparable to the original Cry-consensus peptide, while the mixture of amino acids constituting Cry-consensus peptide did not stimulate PBMC proliferation. PBMCs from healthy subjects did not respond to Cry-consensus peptide at all.

DISCUSSION

These data indicate that the PBMC response of patients suffering from JC pollinosis to Cry-consensus peptide is specific for the sequence of T cell epitopes thereof and may be useful for the evaluation of the efficacy of Cry-consensus peptide in vivo.

A comprehensive model of allergic rhinitis in guinea pigs

INTRODUCTION

The economic and social impact of allergic rhinitis is substantial. The effectiveness of currently available medications is limited and therefore investigations for more effective drugs is essential. This study was intended to establish a model of allergic rhinitis in guinea pigs that can be utilized for further investigation of new drugs.

METHODS

Male Dunkin Hartley guinea pigs were sensitized intranasally to, and challenged with, ovalbumin. Sneezing (SN) and nose rubbing (NR) response to allergen challenge were observed on day 21 post-initiation of sensitization in conscious guinea pigs. Nasal blockade (NB), leukocyte infiltration, and lung inflation pressure (LIP) were assessed in the same guinea pigs 23-28 days post-initiation of sensitization. A ventilator/flow method was used to measure NB and LIP. Leukocyte infiltration into nasal lavage fluid 60 min after challenge in the same animals was recorded as total and differential cell counts.

RESULTS

Sensitized guinea pigs produced acute allergic responses after allergen challenge. This was characterized by increases in SN, NR, NB, and eosinophil infiltration. In addition, intranasal allergen challenge did not change lung inflation pressure.

DISCUSSION

Allergen-induced rhinitis in guinea pigs resembles that in humans. The model reported in this study can be used to reflect the effectiveness of drugs currently used to treat allergic rhinitis and to investigate new potential drugs for the treatment of allergic rhinitis.