RESUMO
The study investigated the influence of atmospheric plasma processing on cashew nut composition as well as on its allergenicity. The cashew nuts were processed by low-pressure plasma, using glow discharge plasma (80â¯W and 50â¯kHz power supply). Anacardic acids and allergens were quantified by HPLC and immunoassay, respectively. Additionally, the overall composition was evaluated by 1H qNMR. Increases in amounts of anacardic acids (15:1, 15:2, and 15:3) and fatty acids (oleic, linoleic, palmitic and stearic) were detected after all process conditions, with 70.92% of total variance captured using 2 LVs. The total amount of anacardic acids increased from 0.7 to 1.2⯵g·mg-1 of nut. The major change was observed for anacardic acid (C15:3) with an increase from 0.2 to 0.55⯵g/mg of nut for the samples treated with a flow of 10â¯mL·min-1 and 30â¯min of processing. On the other hand, the amount of sucrose decreased, from 33 to 18â¯mg·g-1 of nut, after all processing conditions. Plasma processing of cashew nuts did not affect binding of either the rabbit anti-cashew or human cashew allergic IgE binding. Among the treatments, 10â¯min of plasma processing at flow rate of 30â¯mL·min-1 of synthetic air followed by 20â¯min at flow rate 5.8â¯mL·min-1 had the least effect on nut composition as a whole.
Assuntos
Anacardium , Manipulação de Alimentos/métodos , Irradiação de Alimentos/métodos , Nozes/química , Nozes/imunologia , Alérgenos/análise , Ácidos Anacárdicos/análise , Animais , Ácidos Graxos/análise , Humanos , Imunoglobulina E/metabolismo , Microscopia Eletrônica de Varredura , Hipersensibilidade a Noz/prevenção & controle , Extratos Vegetais/imunologia , CoelhosRESUMO
The protein content and allergen composition was studied of cashews from 8 different origins (Benin, Brazil, Ghana, India, Ivory Coast, Mozambique, Tanzania, Vietnam), subjected to different in-shell heat treatments (steamed, fried, drum-roasted). On 2D electrophoresis, 9 isoforms of Ana o 1, 29 isoforms of Ana o 2 (11 of the acidic subunit, 18 of the basic subunit), and 8 isoforms of the large subunit of Ana o 3 were tentatively identified. Based on 1D and 2D electrophoresis, no difference in allergen content (Ana o 1, 2, 3) was detected between the cashews of different origins (P > 0.5), some small but significant differences were detected in allergen solubility between differently heated cashews. No major differences in N- and C-terminal microheterogeneity of Ana o 3 were detected between cashews of different origins. Between the different heat treatments, no difference was detected in glycation, pepsin digestibility, or IgE binding of the cashew proteins.
Assuntos
Alérgenos/imunologia , Anacardium/química , Manipulação de Alimentos , Nozes/química , Anacardium/imunologia , Antígenos de Plantas/imunologia , Benin , Brasil , Côte d'Ivoire , Gana , Humanos , Índia , Moçambique , Hipersensibilidade a Noz/imunologia , Nozes/imunologia , Proteínas de Plantas/imunologia , Tanzânia , VietnãRESUMO
Cashew nut allergy is the second most commonly reported tree nut allergy. Traditional allergen immunotherapy presents several clinical drawbacks that can be reduced by using nanoparticles-basedallergen-delivery systems, modulating the immune response towards a protective one. In this context, the goal of this work was to assess the potential of poly(anhydride) nanoparticles (NP) for cashew nut oral immunization. Cashew nut allergens-loaded nanoparticles (CNE-NP) were prepared by solvent displacement method. After nanoparticles characterization, oral immunomodulation ability was evaluated in BALB/c mice. Our results demonstrated that CNE-NP induced a higher Th1/Th2 ratio in comparison with animals immunized with free cashew nut proteins. Indeed, a decrease in splenic Th2 cytokines (IL-4, IL-5, and IL-13), and an enhancement of pro-Th1 (IL-12 and IFN-γ) and regulatory (IL-10) cytokines was observed. Furthermore, mice orally immunized with CNE-NP presented an increased expansion of CD4+ T regulatory cells, such as CD4+Foxp3+ and CD4+LAP+, in the mesenteric lymph nodes. In conclusion, oral immunization with a single dose of poly(anhydride) nanoparticles loaded with cashew nut proteins leaded to a pro-Th1 and Treg immune response. Furthermore, their immunomodulatory properties could be introduced as a new approach for management of cashew nut allergy.
Assuntos
Anacardium/imunologia , Anidridos/imunologia , Nanopartículas/efeitos adversos , Hipersensibilidade a Noz/imunologia , Nozes/imunologia , Linfócitos T Reguladores/imunologia , Células Th1/imunologia , Administração Oral , Alérgenos/imunologia , Animais , Linfócitos T CD4-Positivos/imunologia , Citocinas/imunologia , Dessensibilização Imunológica/métodos , Linfonodos/imunologia , Camundongos , Camundongos Endogâmicos BALB CRESUMO
BACKGROUND: Almonds and Brazil nuts are widely consumed allergenic nuts whose presence must be declared according to food labelling regulations. Their detection in food products has been recently achieved by ELISA methods with recombinant antibodies (scFv) isolated against complete Brazil nut and almond protein extracts. The screening of phage-scFv libraries against complete protein extracts confers a series of advantages over the use of purified proteins, as recombinant proteins might alter their native folding. However, using this strategy, the nature of the target detected by phage-displayed antibodies remains unknown, and requires further research to identify whether they are nut allergens or other molecules present in the extract, but not related to their allergenic potential. RESULTS: Electrophoretic, chromatographic, immunological and spectrometric techniques revealed that the Brazil nut (BE95) and almond (PD1F6 and PD2C9) specific phage-scFvs detected conformational epitopes of the Brazil nut and almond 11S globulins, recognised by WHO/IUIS as Ber e 2 and Pru du 6 major allergens. Circular dichroism data indicated that severe heat treatment would entail loss of epitope structure, disabling scFv for target detection. CONCLUSIONS: The presence of important Brazil nut and almond allergens (Ber e 2 and Pru du 6) in foodstuffs can be determined by using phage-display antibodies BE95, PD1F6 and PD2C9 as affinity probes in ELISA. © 2017 Society of Chemical Industry.
Assuntos
Bacteriófagos/genética , Bertholletia/imunologia , Prunus dulcis/imunologia , Anticorpos de Cadeia Única/imunologia , Bacteriófagos/metabolismo , Bertholletia/química , Reações Cruzadas , Mapeamento de Epitopos , Epitopos/química , Epitopos/imunologia , Nozes/química , Nozes/imunologia , Proteínas de Plantas/química , Proteínas de Plantas/imunologia , Prunus dulcis/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Anticorpos de Cadeia Única/genéticaRESUMO
BACKGROUND: Previous studies have reported reactions to an increasing range of nuts as patients with nut allergy grow older. Most patients with symptoms suggesting nut allergy have specific IgE to more than one nut. Furthermore, fatal reactions have followed eating nuts different from any causing the deceased's previous reactions. OBJECTIVE: To explore the pattern of specific IgE to three distantly related nuts in patients of all ages with nut allergy. METHODS: This study includes all patients referred to our laboratory for nut allergy testing from January 1994 to August 1998 who were tested for peanut, hazelnut and brazil nut, and had specific IgE to at least one of these nuts. All tests were performed using the Pharmacia Unicap system. RESULTS: Seven hundred and thirty-one patients (age 7 months to 65 years, median 6.6 years) had specific IgE >0.35 kU(A)/L to at least one of these three nuts: 282 had IgE to one nut, 130 to two nuts, and 319 to all three nuts. When analysed by gender and age quartile, very similar patterns were found in all subgroups though significant age trends and age interactions were found for IgE to individual nuts and combinations of nuts. CONCLUSIONS: The probability of a patient with nut allergy having specific IgE to a particular combination of peanut, hazelnut and brazil nut is similar, whatever their age or sex. The apparent increase in multiple nut reactivity with increasing age may therefore be due to exposure of previously unchallenged sensitivity. The frequency of multiple-nut specificity is sufficiently high that patients should always be tested for allergy to a range on nuts if they have a history of reacting to any nut.
Assuntos
Alérgenos/imunologia , Arachis/imunologia , Hipersensibilidade Alimentar/imunologia , Imunoglobulina E/sangue , Nozes/imunologia , Adolescente , Adulto , Distribuição por Idade , Idoso , Alérgenos/efeitos adversos , Arachis/efeitos adversos , Criança , Pré-Escolar , Feminino , Hipersensibilidade Alimentar/epidemiologia , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Nozes/efeitos adversos , Distribuição por SexoRESUMO
BACKGROUND: Only a few studies have investigated the clinical role of food allergens, especially the relationship between sensitization to a given allergen and occurrence of adverse reactions when eating the relevant food item. OBJECTIVE: This study evaluated the clinical role of the allergens of Brazil nut by comparing the patterns of IgE binding in sera from 11 patients with anaphylaxis after eating Brazil nuts with those from 10 subjects with no symptoms to this food item. Both groups had specific IgE to Brazil nut. METHODS: Allergens in the in-house extract of Brazil nut were identified by SDS-PAGE/immunoblotting, the major allergen was purified by HPLC, and its N-terminal sequence was determined by a protein sequencer. RESULTS: SDS-PAGE/immunoblotting detected a number of allergenic components with molecular weights ranging from 4 to 58 kd. All sera from symptomatic patients recognized a 9-kd allergen corresponding (as established by amino acid sequencing) to a 2S albumin already described as a major allergen of Brazil nut, whereas the other allergens each bound IgE from less than 50% of sera. No sera from asymptomatic subjects showed IgE binding to the 9-kd allergen, but they did recognize components from 25 to 58 kd, which are minor allergens. CONCLUSIONS: These findings indicate that the allergen underlying clinical reactions to Brazil nut is a 2S albumin of 9 kd and that in vitro reactivity to this allergen identifies subjects who react in vivo to ingestion of this food.
Assuntos
Albuminas/imunologia , Hipersensibilidade Alimentar/imunologia , Nozes/imunologia , Precursores de Proteínas/imunologia , Albuminas 2S de Plantas , Adolescente , Adulto , Albuminas/antagonistas & inibidores , Albuminas/isolamento & purificação , Sequência de Aminoácidos , Antígenos de Plantas , Ligação Competitiva , Criança , Pré-Escolar , Cromatografia Líquida de Alta Pressão , Feminino , Humanos , Immunoblotting , Focalização Isoelétrica , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Nozes/efeitos adversos , Reação do Ácido Periódico de Schiff , Precursores de Proteínas/antagonistas & inibidores , Precursores de Proteínas/isolamento & purificação , Análise de SequênciaRESUMO
The increase in the consumption of tropical nuts in the Northern Hemisphere during the last years, has evolved in a simultaneous enhancement of allergic IgE mediated (Hypersensitivity type 1) reported cases produced by this kind of food. The Brazil nut is the seed of the Bertholletia excelsa tree (Family Lecythidaceae) and, as in other seeds, proteins represent one of its major components making up 15-17% of its fresh weight and 50% of defatted flour. Of these, storage proteins are the most important ones, and the 12 S globulin legumin-like protein and the 2 S albumin have been described as the most representative. The 2 S protein, due to its high sulfur-rich amino acid content (3% cysteine and 18% methionine), is being studied, cloned and expressed in some important agronomic seeds (soybean, bean, oilseed rape) in order to enrich the nutritional quality of them. The case of a patient with serious clinical allergic symptoms (vomiting, diarrhoea and loss of consciousness) caused by oral contact with the Brazil nut, is presented. The patient gave a positive Skin Prick Test response to Brazil nut, kiwi and hazelnut extracts, and negative to regionally specific aeroallergens and other food extracts. The patient serum showed a high level of specific IgE by RAST to Brazil nut (> 17.5 PRU/ml, Class 4), and significative levels to hazelnut, and mustard. In vitro immunological studies (SDS-Immunoblotting and IEF-Immunoblotting) revealed IgE-binding proteins present in the extract. It was shown that not only the heavy (Mr 9) and light (Mr 4) subunits of the known allergenic 2 S albumin but also the alpha-subunits (Mr approximately 33.5 and 32) and at least one of the beta-subunits (Mr approximately 21) of the 12 S Brazil nut globulin, hitherto never involved in allergic problems, showed a strong IgE-binding capacity.
Assuntos
Alérgenos/imunologia , Nozes/imunologia , Proteínas de Plantas/imunologia , Adolescente , Alérgenos/isolamento & purificação , Western Blotting , Reações Cruzadas , Feminino , Hipersensibilidade Alimentar/imunologia , Engenharia Genética , Humanos , Imunoglobulina E/imunologia , Nozes/química , Proteínas de Plantas/isolamento & purificação , Teste de Radioalergoadsorção , Proteínas Recombinantes/efeitos adversos , Proteínas Recombinantes/imunologia , Testes CutâneosRESUMO
BACKGROUND: The nutritional quality of soybeans (Glycine max) is compromised by a relative deficiency of methionine in the protein fraction of the seeds. To improve the nutritional quality, methionine-rich 2S albumin from the Brazil nut (Betholletia excelsa) has been introduced into transgenic soybeans. Since the Brazil nut is a known allergenic food, we assessed the allergenicity of the 2S albumin. METHODS: The ability of proteins in transgenic and non-transgenic soybeans, Brazil nuts, and purified 2S albumin to bind to IgE in serum from subjects allergic to Brazil nuts was determined by radioallergosorbent tests (4 subjects) and sodium dodecyl sulfate-polyacrylamide-gel electrophoresis (9 subjects) with immunoblotting and autoradiography. Three subjects also underwent skin-prick testing with extracts of soybean, transgenic soybean, and Brazil nut. RESULTS: On radioallergosorbent testing of pooled serum from four subjects allergic to Brazil nuts, protein extracts of transgenic soybean inhibited binding of IgE to Brazil-nut proteins. On immunoblotting, serum IgE from eight of nine subjects bound to purified 2S albumin from the Brazil nut and the transgenic soybean. On skin-prick testing, three subjects had positive reactions to extracts of Brazil nut and transgenic soybean and negative reactions to soybean extract. CONCLUSIONS: The 2S albumin is probably a major Brazil-nut allergen, and the transgenic soybeans analyzed in this study contain this protein. Our study show that an allergen from a food known to be allergenic can be transferred into another food by genetic engineering.