Identification of the 7S and 11S globulins as percutaneously sensitizing soybean allergens as demonstrated through epidermal application of crude soybean extract

Cutaneous exposure to food allergens can predispose individuals to food allergies. Soybean, a major allergenic food, is an ingredient in various cosmetic products. However, the types of soybean proteins that are percutaneously sensitizing in humans or animal models remain unknown. In this study, BALB/c mice were dorsally shaved and epicutaneously exposed to a crude soybean extract including sodium dodecyl sulfate or distilled water alone. Specific IgEs secreted in response to 7S globulin (Gly m 5), 11S globulin (Gly m 6), Gly m 3, and Gly m 4 were measured using enzyme-linked immunosorbent assays or immunoblots. Exposure to soybean extract elicited the secretion of soybean-specific IgEs. Of the soybean proteins, 7S and 11S globulins acted as percutaneous sensitizers in 6/9 mice (67%). Additionally, IgE bound specifically and preferentially to the 7S globulin β subunit. In conclusion, this is the first report to identify percutaneously sensitizing soybean allergens in a mouse model.     

Experimental food allergy leads to adipose tissue inflammation, systemic metabolic alterations and weight loss in mice

To investigate the consequences of food allergy in adipose tissue and metabolism, we used a murine model in which mice have been sensitized subcutaneously with ovalbumin and further received antigen-containing diet. Allergic mice presented a significant weight loss 7 days after oral challenge with a concomitant decrease in epididymal adipose tissue mass. This decrease was associated with increased lipolysis and local inflammation. In adipose tissue of allergic mice there were increased leukocyte rolling and adhesion in the microvasculature, increased number of leukocytes in the tissue, especially macrophages (F4/80⁺ cells) and increased pro-inflammatory cytokines levels, including TNF-α, IL-6 and CCL2. In addition, we observed low serum concentrations of triglyceride, glucose, total cholesterol and free fatty acids in the allergic mice. Our results suggest that the induction of food allergy in mice leads to adipose tissue inflammation and systemic metabolic alterations that contribute to the weight loss observed.     

Novel T-cell epitopes of ovalbumin in BALB/c mouse: Potential for peptide-immunotherapy

The identification of food allergen T-cell epitopes provides a platform for the development of novel immunotherapies. Despite extensive knowledge of the physicochemical properties of hen ovalbumin (OVA), a major egg allergen, the complete T-cell epitope map of OVA has surprisingly not been defined in the commonly used BALB/c mouse model. In this study, spleen cells obtained from OVA-sensitized mice were incubated in the presence of 12-mer overlapping synthetic peptides, constructed using the SPOTS^® synthesis method. Proliferative activity was assessed by 72-h in vitro assays with use of the tetrazolium salt WST-1 and led to identification of four mitogenic sequences, i.e., A39R50, S147R158, K263E274, and A329E340. ELISA analyses of interferon (IFN)-γ and interleukin (IL)-4 productions in cell culture supernatants upon stimulation with increasing concentrations of peptides confirmed their immunogenicity.Knowledge of the complete T-cell epitope map of OVA opens the way to a number of experimental investigations, including the exploration of peptide-based immunotherapy.     

IgE binding to proteins from sesame and assessment of allergenicity: implications for biotechnology?

Successful prediction of the potential allergenicity of a protein may be a key factor in the development of novel, genetically modified foods. The use of the decision tree approach for the prediction of allergenicity is discussed. The methods currently used for identifying allergenic proteins (including use of IgE from patient sera for recognition of proteins) are reviewed. Finally, a specific review of the literature concerning identification of allergens from sesame leads to the conclusion that in the absence of validated animal models, identification of allergenicity (and, consequently, prediction of allergenicity) may be problematic.     

Detection and side-chain specificity of IgE antibodies to flucloxicillin in allergic subjects

Unlike studies on the antigenicity of penicillins in laboratory animals, limited information is available on the allergenicity of penicillins in man, especially with regard to fine structural allergenic differences between the many different penicillins. Inconsistent with the earlier conclusions of others, our studies suggest that side-chain structures to flucloxacillin-reactive IgE antibodies. Quantitative hapten inhibition studies revealed potent inhibition by flucloxacillin and three structurally related penicillins: oxacillin, cloxacillin and dicloxacillin. Analysis of the results showed that the side-chain group of flucloxacillin, 3-2(-chloro-6-fluorophenyl)-5-methyl-4-isoxazolyl, is recognized by some antibodies and that the 5-methyl-3-phenyl-4-isoxazolyl group, with or without halogen substituents, accounts for the reactivity of other antibodies and for the cross-reactions seen with some other penicillins. Since it is the side-chain group that distinguishes the many different types of penicillin, and since IgE antibodies in many of the allergic reactions recognize the side-chain groups, it is becoming clear that specific assays are required for the detection of IgE antibodies to each of the different penicillins.     

Aeroallergens and pollinosis: Molecular and immunological characteristics of cloned pollen allergens

Affecting almost twenty percent of thepopulation in industrialized countries,allergic diseases such as asthma and seasonalrhinitis result from the development ofimmediate hypersensitivity to otherwiseinnocuous components of the environment. Pollen, the male gametophyte of flowering plantspecies, is one of the most predominant sourcesof environmental allergens, and a significantcause of allergic diseases. This reviewdiscusses the nature of pollen proteins asallergens, their effect on the human immunesystem and their mode of environmentaltransmission, including effects of theinteraction between pollen aeroallergens andair pollution. The influence of cross-reactivepollen allergens to the incidence of foodsensitivities is also discussed. Floweringplant species that possess allergenic pollen,identified with allergens cloned from thesespecies, are also discussed.     

Role of IL-4 in aversion induced by food allergy in mice

To ascertain the role of IL-4 in aversion to antigen induced by food allergy, wild type and IL-4 deficient BALB/c mice were sensitized with ovalbumin and challenged orally with egg white. Sensitized wild type mice had increased production of IL-4 by spleen and mesenteric lymph node cells in vitro, higher levels of serum anti-ovalbumin IgE and IgG1, aversion to ingestion of the antigen and loss of body weight after continuous oral challenge. Intestinal changes in wild type sensitized mice included eosinophil infiltration and increased mucus production. The IL-4 deficiency impaired the development of food allergy and the aversion to antigen, suggesting the involvement of the antigen specific antibodies. When IL-4 deficient mice received serum from sensitized wild type donors, the aversion was restored. These results indicate that production of IL-4 and specific IgE/IgG1 antibodies correlate with aversion to antigen induced by food allergy in mice.     

食物过敏儿童肠道正常菌群的定量调查与分析

目的探讨儿童食物过敏与肠道正常菌群的关系。方法采集食物过敏儿童与正常儿童粪便,每例作需氧或厌氧培养、计数与鉴定。结果食物过敏儿童肠道中的双歧杆菌、乳酸杆菌、肠杆菌数量与正常儿童差异有显著性（P〈0．05）。结论食物过敏与肠道菌群失调有密切关系。     

婴儿双歧杆菌对花生过敏小鼠模型肠道Th2反应的调节

目的研究婴儿型双歧杆菌对花生过敏小鼠肠道Th2型反应的调节作用。方法通过应用花生蛋白诱导肠道的Th2型反应,建立食物过敏小鼠模型。过敏小鼠灌胃给予婴儿型双歧杆菌（ATCC菌或CGMCC0313-2）或不做处理。然后分离小鼠小肠黏膜CD4＋T细胞或DC,另取肠黏膜组织进行石蜡包埋甲苯胺蓝染色肥大细胞计数,HE染色进行嗜酸细胞和单个核细胞计数,流式细胞检测CD4＋T中Th2（CD4＋IL4＋T）细胞和Treg（CD4＋CD25＋Foxp3＋T）比例,另取CD4＋T进行CFSE标记,与DC共培养4d后流式细胞检测CD4＋T增殖反应,收集细胞培养液ELISA检测IL-4、IL-5和IL—13分泌水平。结果过敏组小鼠Th2型细胞数,CD4＋T细胞增殖反应,IL4、IL-5和IL-13水平,肠黏膜中肥大细胞、嗜酸性细胞和单个核细胞数均明显高于对照组（P〈0．01）,而Treg数目低于对照组（P〈0．01）,婴儿双歧杆菌干预后,婴儿双歧杆菌组Th2型细胞数,IL4、IL-5和IL-13水平,肠黏膜中肥大细胞、嗜酸性细胞和单个核细胞数均明显低于过敏组（P〈0．01）,而Treg数目高于过敏组（P〈0．01）。结论口服婴儿型双歧杆菌可以抑制花生过敏导致的肠道Th2型反应。     

β-Lactam drug allergens: Fine structural recognition patterns of cephalosporin-reactive IgE antibodies

Lack of experimental findings on the spectrum of cephalosporin allergenic determinants has hindered diagnosis of adverse reactions to these drugs and retarded understanding of allergenic cross-reactions between cephalosporins and between cephalosporins and penicillins. Subjects allergic to the widely used cephalosporin antibiotic cefaclor have serum immuno globulin (Ig) E antibodies that react with the drug. Quantitative hapten inhibition studies employing sera from subjects allergic to cefaclor revealed fine structual recognition differences between the combining site specificities of cefaclor-reactive IgE antibodies in the sera of different subjects. Unlike penicillins, where discrete side chain or thiazolidine ring determinants alone may be recognized, IgE binding determinants on cefaclor encompassed the entire molecule. Fine structural recognition specificity differences at positions R₁ (side-chain) and R₂ (substituent attached to dihydrothiazine ring) were detected between IgE antibodies in different sera. Some antibodies showed clear preferential recognition of the aminobenzyl group at position R₁ and Cl at R₂ while with others, a greater degree of recognition tolerance was seen at R₁ where, for example, the aminohydroxybenzyl or aminodihydrobenzyl groups were recognized, and at R₂ where a methyl or even an ester group was tolerated. As with the penicillins, cephalosporins as allergens cannot simply be considered as a group of compounds with a common allergenic determinant structure. IgE antibodies that bind to cefaclor show great heterogeneity indicated by clear, fine structural differences in recognition of the R₁ and R₂ groups on the drug.     

Oral administration of ovalbumin after sensitization attenuates symptoms in a mouse model of food allergic enteropathy

Oral immunotherapy (OIT) is a promising treatment of food allergy. To administer an appropriate oral dose of an allergenic component as OIT to individuals sensitized with a food allergen may prevent inducing food allergic inflammation in them. So we attempted to establish a mouse model to evaluate efficacy for oral administration of food allergen after sensitization. In BALB/c mice sensitized by injecting ovalbumin (OVA) with alum twice, OVA was administered before inducing inflammation by feeding the mice with egg white (EW) diet. Severe inflammatory responses, such as enteropathy, weight loss, IL-4 production, and increase of IgE antibody levels, were suppressed by administration with 4 mg of OVA 7 times before feeding EW diet. OVA administration alone induced a slight Th2 response, but no symptoms. The current study demonstrated that severe food allergic enteropathy could be prevented by pre-administration with appropriate dose of OVA to sensitized mice.     

食物过敏婴儿和健康儿肠道菌群分析

目的检测食物过敏婴儿与健康婴儿的大便菌群,为食物过敏与肠道菌群关系的研究提供依据。方法以在重庆儿童医院体检的52例食物过敏婴儿和年龄、性别匹配的100例健康婴儿为研究对象,收集所有对象的新鲜粪便,采用直接快速涂片法分析肠道菌群。结果食物过敏婴儿革兰阳性杆菌比例降低,革兰阴性杆菌、革兰阳性球菌比例增高[(71.43±8.70)%vs(78.91±9.25)%,(15.69±6.26)%vs(11.85±6.66)%,(11.67±4.02)%vs(7.60±4.27)%,P均<0.001]。不同喂养方式下,食物过敏婴儿的大便菌群比例显示不同的改变,但革兰阳性杆菌比例降低是其共同的特点(P均<0.05)。结论食物过敏婴儿肠道菌群与健康婴儿的肠道菌群差异存在显著性。不同喂养方式的婴儿显示不同的大便菌群组成。肠道正常菌群的改变可能在食物过敏的发生中起一定作用。     

Ani s 10, a new Anisakis simplex allergen: cloning and heterologous expression

Anisakiasis is a human disease caused by accidental ingestion of larval nematodes belonging to the Anisakidae family. Anisakiasis is often associated with a strong allergic response. Diagnosis of A. simplex allergy is currently carried out by test based on the IgE reactivity to a complete extract of L3 Anisakis larvae although the specificity of these diagnostic tests is poor. Improving the specificity of the diagnostic test is possible using purified recombinant allergens. A new Anisakis allergen, named Ani s 10, was detected by immunoscreening an expression cDNA library constructed from L3 Anisakis simplex larvae. The new allergen was overproduced in Escherichia coli; it is a protein of 212 amino acids and it was localized as a 22 kDa protein band in an ethanol fractionated extract from the parasite. Ani s 10 has no homology with any other described protein, and its sequence is composed by seven almost identical repetitions of 29 amino acids each. A total of 30 of 77 Anisakis allergic patients (39%) were positive both to rAni s 10 and natural Ani s 10 by immunoblotting. The new allergen could be useful in a component-resolved diagnosis system for Anisakis allergy.     

The two faces of mast cells in food allergy and allergic asthma: The possible concept of Yin Yang

The purpose of this review is to discuss the role of mast cells in allergic inflammation. We have focused on inflammation associated with allergic asthma and food allergy. Mast cells are ‘first line of defense’ innate/adaptive immune cells and are widely distributed in tissues in surfaces exposed to the environment. Especially in allergic settings mast cells are extensively studied, as they can be activated to release a wide range of mediators by allergen-IgE specific triggers. In addition, in allergic inflammation mast cells can also be activated non-allergic triggers. Recent studies revealed that mast cells, besides the classical role of pro-inflammatory effector cell, have also emerged as modulators of allergic sensitization and down-regulators of allergic inflammation. Therefore, mast cells can be regarded as ‘Ying Yan’ modulators in allergic responses in intestinal tract and airways. This article is part of a Special Issue entitled: Mast Cells in Inflammation.     

异位性皮炎患者血清变应原过筛检测结果及其临床意义

目的:探讨异位性皮炎(AD)患者的血清嗜酸细胞阳离子蛋白(ECP)、总IgE、吸入性变应原Phadiatop和食物性变应原fx5E间的相关性。方法:随机选取我院门诊就诊和住院治疗的AD患者60例,选取健康体检者30例为对照组,同期检测ECP、总IgE、Phadiatop和fx5E血清浓度并比较。结果:AD患者血清ECP和总IgE水平均明显高于正常对照组(P<0.05);患者组中血清ECP与总IgE之间无相关性;Phadiatop在患者组中阳性率为86.67%,fx5E阳性率为18.33%。结论:AD患者血清ECP水平是反映嗜酸粒细胞活化和过敏状态的敏感指标,能更有效地监测AD患者病情变化与疗效。吸入性和食物性变应原均可引起AD,尤以吸入性变应原为主。对AD患者进行CAP系统中变应原过筛检测,是AD防治的重要手段之一。     

双歧杆菌完整肽聚糖对食物过敏小鼠调节性T细胞影响的研究

目的以食物过敏小鼠为动物模型,通过灌喂双歧杆菌完整肽聚糖(Whole Peptidoglycan,WPG),观察其对调节性T细胞的作用。方法 4～6周龄SPF级无鸡蛋喂养BALB/c雌鼠随机分为3组,每组8只。取其中2组建立食物过敏模型,分别为OVA致敏阳性对照组、OVA激发后灌喂双歧杆菌WPG治疗组和生理盐水对照组。采用ELISA法检测各组血清中OVA特异性IgE、IL-10和TGF-β1水平;流式细胞术分析脾脏单个核细胞悬液中CD4+CD25+调节性T细胞的数量变化。结果 OVA组IL-10、TGF-β1水平显著高于对照组(P分别0.05和0.01);WPG组血清IL-10和TGF-β1水平显著低于OVA组(P0.05)。OVA组脾CD4+CD25+T淋巴细胞的百分比低于对照组(P0.05),WPG组与OVA组相比有升高趋势,差异有统计学意义(P0.05);OVA组脾Foxp3+CD4+CD25+调节性T细胞的百分比显著低于对照组(P0.01),WPG组与OVA组相比有升高趋势,差异有统计学意义(P0.01)。结论双歧杆菌WPG可以增加食物过敏小鼠CD4+CD25+调节性T细胞数量,刺激细胞因子IL-10和TGF-β分泌。     

Downregulation in aquaporin 4 and aquaporin 8 expression of the colon associated with the induction of allergic diarrhea in a mouse model of food allergy

Food allergies have become increasingly prevalent during the past few decades. Diarrhea is one of the most frequent intestinal symptoms caused by food allergens and is characterized by imbalanced ion exchange and water transfer; however, the underlying mechanism of allergic diarrhea remains unclear. Water transfer across the intestinal epithelial membrane seems to occur via aquaporins (AQPs). However, the molecular mechanism of water transfer and the pathophysiological roles of aquaporins in the intestine have not been fully established. The present studies have focused on the alterations of AQPs in a mouse model of allergic diarrhea in which BALB/c mice developed diarrhea following repeated challenges of orally administered ovalbumin. Quantitative real-time PCR analysis and immunohistochemical technique were used for expression of mRNA and protein of AQPs, respectively. AQP4 and AQP8 mRNA levels were significantly decreased in the proximal colon of allergic mice compared to controls; likewise, expression of AQP4 and AQP8 proteins was reduced in the proximal colon of the allergic mice. These results suggest that allergic diarrhea is associated with a downregulation in AQP4 and AQP8 expression.