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BACKGROUND: The interaction between food allergens and plant polyphenols has become a safe and effective management strategy to prevent food allergies. Ovalbumin (OVA) is the most abundant allergen in egg whites. Resveratrol (RES) is a plant polyphenol that is abundant in red grapes, berries, and peanuts, and has an anti-allergic effect on allergy-related immune cells. However, there is little information about the effect of RES on the allergenicity of OVA. In this study, the effect of RES on the allergenicity of OVA was investigated. RESULTS: Molecular docking and spectroscopic studies indicated that the addition of RES changed the structure of OVA. The digestion and transfer rate of OVA-RES were effectively improved with an in vitro gastrointestinal digestion model and Caco-2 cell model, especially when the molar ratio of OVA-RES was 1:20. Meanwhile, the KU812 cell degranulation assay proved that the potential allergenicity was remarkably decreased while the molar ratios of OVA-RES were increased to 1:20. Furthermore, hydrogen bonds and van der Waals forces were the dominating forces to stabilize the OVA-RES complexes. CONCLUSION: All the findings demonstrated that the potential allergenicity of OVA was reduced when interacting with RES, and RES can be a potential food material for preparing a hypoallergenic protein, especially for egg allergy. © 2023 Society of Chemical Industry.
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Alérgenos , Hipersensibilidad a los Alimentos , Humanos , Ovalbúmina/química , Resveratrol , Simulación del Acoplamiento Molecular , Células CACO-2 , Inmunoglobulina E , Hipersensibilidad a los Alimentos/prevención & controlRESUMEN
Active polysaccharides are extensively utilized in the fields of food and medicine because of their rich functional properties and structural plasticity. However, there are still few systematic studies and reviews on active polysaccharides for allergy. Allergy, especially food allergy, occurs frequently around the world and is related to a variety of factors such as age, genetics and dietary habits. Currently in medicine, avoiding allergens and desensitizing can effectively relieve allergy symptoms, but these are difficult to maintain over the long term and come with risks. Based on the supplementation of dietary nutrition to these two treatments, it has been discovered in recent years that the use of active ingredients from natural substances can effectively intervene in allergies. Considering the potential of active polysaccharides in this regard, we systematically characterize the latent patterns of polysaccharides in allergic symptoms and pathogenesis, including the aspects of gut, immunomodulatory, oxidative stress and signaling pathways, as well as the application prospect of them in allergy. It can be found that active polysaccharides have excellent anti-allergic potential, especially from the ocean. We believe that the active polysaccharides are associated with the treatment of allergic diseases, which may provide the benefits to allergy sufferers in the future.
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Food allergy has become a major public health problem all over the world. Evidence showed that allergic reactions induced by food proteins often lead to disturbances in the gut microbiota (symbiotic bacteria). Gut microbiota plays an important role in maintaining the balance between intestinal immune tolerance and allergic reactions. Dietary intervention has gradually become an important method for the prevention and treatment of allergic diseases, and changing the composition of gut microbiota through oral intake of prebiotics and probiotics may serve as a new effective adjuvant treatment measure for allergic diseases. In this paper, the main mechanism of food allergy based on intestinal immunity was described firstly. Then, the clinical and experimental evidence showed that different prebiotics and probiotics affect food allergy by changing the structure and composition of gut microbiota was summarized. Moreover, the molecular mechanism in which the gut microbiota and their metabolites may directly or indirectly regulate the immune system or intestinal epithelial barrier function to affect food immune tolerance of host were also reviewed to help in the development of food allergy prevention and treatment strategies based on prebiotics and probiotics.
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Dairy processing can alter the digestion stability and bioavailability of cow milk proteins in the gastrointestinal tract. However, analysis of stable linear epitopes on cow milk allergens that could enter into intestinal mucosal is limited. Thus, this study aimed to investigate the digestion and transportation properties and residual allergen epitopes entering into gastrointestinal mucosa of 3 commercial dairy products, including pasteurized milk (PM), ultra-heat-treated milk (UHTM), and dried skim milk (DSM). In this work, the digestive stability of the 3 kinds of dairy products has been performed in a standard multistep static digestion model in vitro and characterized by Tricine-SDS-polyacrylamide gel electrophoresis and reversed-phase HPLC. With respect to gastrointestinal digestion in vitro, the main allergens including ß-lactoglobulin (ß-LG), α-lactalbumin (α-LA), and caseins were degraded gradually, and the resistance peptides remained in the PM with a molecular weight of range from 3.4 to 5.0 kDa. Simultaneously, the potential allergenicity of the cow milk proteins was diminished gradually and is basically consistent after 60 min of gastrointestinal digestion. After gastrointestinal digestion, the remaining peptides were transported via an Ussing chamber and identified by liquid chromatography-MS/MS. By alignment, 10 epitopes peptides were identified from 16 stable peptides, including 5 peptides (AA 92-100, 125-135, 125-138, and 149-162) in ß-LG, 2 peptides in α-LA (AA 80-93 and 63-79), 2 peptides in αS1-casein (AA 84-90 and 125-132), and 1 peptide (AA 25-32) in αS2-casein were identified by dot-blotting mainly exist in UHTM and PM. This study demonstrates dairy processing can affect the digestion and transport characteristics of milk proteins and in turn alter epitope peptides release.
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Alérgenos , Inmunoglobulina E , Bovinos , Femenino , Animales , Alérgenos/metabolismo , Epítopos , Espectrometría de Masas en Tándem/veterinaria , Caseínas/análisis , Leche/química , Lactoglobulinas/análisis , Proteínas de la Leche/análisis , Lactalbúmina/análisis , Péptidos/química , DigestiónRESUMEN
Bovine ß-lactoglobulin (ß-LG) is recognized as a major allergen in milk. This study aimed to investigate ultrasound-assisted irradiation for reducing the allergenicity of ß-LG, since irradiation can reduce the allergenicity of cow milk proteins and ultrasound can improve the quality of milk. The structural changes induced in high purity ß-LG, treated by irradiation, with or without sonication, were characterized by native PAGE, circular dichroism spectroscopy, and fluorescence spectroscopy. The changes in allergenicity were measured by IgE binding capacity to, and inflammatory mediator secretion by, human basophil KU812 cells. Surface hydrophobicity was reduced and aggregation of ß-LG increased after treatment by irradiation, both with and without sonication. The IgE binding capacity and release of inflammatory mediators were reduced significantly and the reduction induced by irradiation before sonication was the greatest, suggesting that irradiation after sonication can be a safe and effective method to reduce the allergenicity of ß-LG in dairy processing.
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Alérgenos/química , Lactoglobulinas/química , Lactoglobulinas/inmunología , Leche/química , Alérgenos/inmunología , Animales , Bovinos , Preescolar , Dicroismo Circular , Electroforesis en Gel de Poliacrilamida , Femenino , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Inmunoglobulina E/inmunología , Lactante , Lactoglobulinas/efectos de la radiación , Masculino , Hipersensibilidad a la Leche , Conformación Proteica , Sonicación , Espectrometría de FluorescenciaRESUMEN
BACKGROUND: Peanut is among the most common of food allergies, and one of its allergens is Ara h 2. A previous study revealed that this allergen was recognized by serum immunoglobulin E (IgE) in over 90% of a peanut-allergic patient population. Enzymatic cross-linking is a popular processing method used to tailor food functionality, such as antigenicity. RESULT: The cross-linking reactions of Ara h 2 were catalyzed by polyphenol oxidase (PPO), and the relevant reaction sites were identified using mass spectrometry and StavroX software. Two pairs of intramolecular cross-linking peptides and two intermolecular cross-linking peptides were found. Intramolecular cross-linking was speculated to occur between ARG131 (amino acids 116-131) and TYR65 (amino acids 63-80) and between TYR60 (amino acids 56-62) and ARG92 (amino acids 92-102); the intermolecular cross-linking sites were ARG31 with TYR84 or TYR89 and TYR65 or TYR72 with ARG92 or ARG102 . Three out of four cross-linking peptides were found in α-helices, and destruction of this secondary structure resulted in a loose tertiary structure. Although seven linear allergen epitopes were involved in cross-linking, the IgE binding capacity of protein changed slightly, while its sensitization potential decreased in mouse model. CONCLUSION: Exploring the structural change of Ara h 2 after cross-linking is beneficial in further understanding the influence of structure on sensitization. This result indicated the future possibility of precision processing on structure of proteins to improve their properties. © 2019 Society of Chemical Industry.
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Albuminas 2S de Plantas/química , Albuminas 2S de Plantas/inmunología , Catecol Oxidasa/química , Secuencia de Aminoácidos , Arachis/química , Arachis/inmunología , Biocatálisis , Epítopos/química , Epítopos/inmunología , Manipulación de Alimentos , Humanos , Inmunoglobulina E/inmunología , Hipersensibilidad al Cacahuete/inmunología , Estructura Secundaria de ProteínaRESUMEN
BACKGROUND: This study aimed to investigate the reduction in the potential allergenicity of soymilk, and its rheological properties, after fermentation with Lactobacillus. Soymilk (SM) was fermented with Lactobacillus brevis and Lactobacillus sp. The molecular weight of fermented soymilk (FSM) was characterized using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and the potential allergenicity of FSM was analyzed using enzyme-linked immunosorbent assay in vitro and the BALB/c mouse model to detect changes in histamine, mouse mast cell protease-1 (mMCP-1), allergen-specific IgG/IgE, and cytokine levels and histomorphology of jejunum in vivo. RESULTS: The SDS-PAGE and enzyme linked immunosorbent assay (ELISA) showed that allergens of soybean (ß-conglycinin and acidic subunit of glycinin) were almost degraded, and their immunoreactivity was decreased. In the BALB/c mouse model, the FSM group did not show anaphylactic shock symptoms compared with the SM group. Moreover, a tendency toward decreased serum allergen-specific IgG/IgE levels, plasma histamine levels, and mMCP-1 concentrations was observed in the FSM group. Furthermore, Th2-related cytokines were decreased, while IFN-γ production increased in spleen cell cultures. The intestinal villus was slightly damaged after the challenge. All these findings indicated that the Th1/Th2 balance in the FSM group shifted toward a Th1 response, ultimately reducing the potential allergenicity of FSM. Rheological assessment suggested that FSM has good viscous and pseudoplastic properties. CONCLUSION: Fermentation might be a promising method for producing tasty, hypoallergenic soybean products. © 2019 Society of Chemical Industry.
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Alérgenos/metabolismo , Hipersensibilidad a los Alimentos/inmunología , Glycine max/inmunología , Glycine max/microbiología , Lactobacillus/metabolismo , Proteínas de Soja/inmunología , Alérgenos/química , Alérgenos/inmunología , Animales , Biotransformación , Manipulación de Alimentos , Humanos , Inmunoglobulina E/inmunología , Ratones , Ratones Endogámicos BALB C , Reología , Leche de Soja/química , Proteínas de Soja/metabolismo , Glycine max/química , Glycine max/metabolismo , Células TH1/inmunología , Células Th2/inmunologíaRESUMEN
Bovine milk is a recognized allergenic food source with ß-lactoglobulin (BLG) as its major allergen. Reliable detection of BLG epitopes can, therefore, be a useful marker for the presence of milk in processed food products, and for potential allergenicity. At the present, enzyme-linked immunosorbent assays (ELISA) for the detection of BLG are time-consuming and generally not specific to BLG IgE epitopes. In this study, the 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide-activated anti-BLG IgE epitope monoclonal antibody (mAb 1G9) was covalently bound onto the KOH-treated microtiter plate surface. Using this mAb-bound plate in sandwich combination with biotinylated anti-BLG polyclonal antibody-labeled gold nanoparticles, a linear dynamic range between 31.25 and 64 × 103 ng mL-1 with a limit of detection for BLG of 0.49 ng mL-1 was obtained, which is 32 times wider and 16 times more sensitive than conventional sandwich ELISA (sELISA). Total recovery of BLG in spiked food samples was found, without matrix effects. Also in partially hydrolyzed infant formulas, the allergenic BLG residues were detected quantitatively. Compared with conventional and commercial BLG detection sELISAs, our sELISA is reliable, highly BLG epitope-specific, user-friendly, and time-saving and allows accurate detection of potentially allergenic residues in different types of processed foods. This improved sELISA protocol can be easily extended to detect other well-identified and characterized food allergens. Graphical abstract IgE epitope mAb-bound plate in sandwich combination with gold probe for sensitive and rapid detection of bovine ß-lactoglobulin and its potentially allergenic residues.
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Alérgenos/análisis , Anticuerpos Inmovilizados/química , Ensayo de Inmunoadsorción Enzimática/métodos , Oro/química , Fórmulas Infantiles/química , Lactoglobulinas/análisis , Leche/química , Animales , Anticuerpos Monoclonales/química , Bovinos , Humanos , Recién NacidoRESUMEN
BACKGROUND & AIMS: In China, epidemiologic information on celiac disease autoimmunity is scarce and fragmented. We investigated the prevalence of celiac disease autoimmunity in the general Chinese population. METHODS: In a cross-sectional prospective study, 19,778 undiagnosed Chinese adolescents and young adults (age, 16-25 y) were recruited from consecutive new students who underwent routine physical examinations at 2 universities in Jiangxi, China, from September 2010 through October 2013; the students were from 27 geographic regions in China. All subjects were tested for serum IgG, IgG against deamidated gliadin peptides (IgG anti-DGP), and IgA anti-tissue transglutaminase antibodies (IgA anti-tTG). We also analyzed HLA genotypes in subgroups of participants with different results from tests for serum markers of celiac disease. RESULTS: A total of 434 students (2.19%) tested positive for serum markers for celiac disease (95% confidence interval [CI], 1.99%-2.41%), 0.36% of the students tested positive for anti-tTG IgA (95% CI, 0.28%-0.46%), and 1.88% tested positive for anti-DGP IgG (95% CI, 1.70%-2.09%). The prevalence of celiac disease autoimmunity (positive results in assays for anti-tTG IgA and anti-DGP-IgG) was 0.06% (95% CI, 0.03%-0.10%). Celiac disease autoimmunity was associated with the consumption of wheat and female sex. The prevalence in the Shandong province in north China, where wheat is a staple in the diet, was 0.76% (95% CI, 0.21%-1.95%). The frequencies of the HLA-DQ2/-DQ8 genotypes associated with celiac disease were higher in subjects with celiac disease autoimmunity, based on detection of both serum markers, than in subjects with positive results from a single test (P < .01). All subjects with positive results from both assays carried the HLA-DQ2 genotype. CONCLUSIONS: Approximately 2% of adolescents or young adults in China had positive results from assays for serum markers for celiac disease. The prevalence of celiac disease autoimmunity in the Shandong province in north China, where wheat is a staple in the diet, was 0.76%.
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Enfermedad Celíaca/epidemiología , Adolescente , Adulto , Autoanticuerpos/sangre , China/epidemiología , Estudios Transversales , Femenino , Proteínas de Unión al GTP/inmunología , Gliadina/inmunología , Humanos , Inmunoglobulina A/sangre , Inmunoglobulina G/sangre , Masculino , Prevalencia , Estudios Prospectivos , Proteína Glutamina Gamma Glutamiltransferasa 2 , Estudiantes , Transglutaminasas/inmunología , Adulto JovenRESUMEN
Ara h 2 is considered a major allergen in peanut. Due to the difficulty of separation, Ara h 2 had not been fully studied. Immunoaffinity chromatography (IAC) column can separate target protein with high selectivity, which made it possible to purify Ara h 2 from different samples. In this study, IAC method was developed to purify Ara h 2 and its effect was evaluated. By coupling polyclonal antibody (pAb) on CNBr-activated Sepharose 4B, the column for specific extraction was constructed. The coupling efficiency of the IAC column was higher than 90%, which made the capacity of column reached 0.56 mg per 0.15 g medium (dry weight). The recovery of Ara h 2 ranged from 93% to 100% for different concentrations of pure Ara h 2 solutions in 15 min. After using a column 10 times, about 88% of the column capacity remained. When applied to extract Ara h 2 from raw peanut protein extract and boiled peanut protein extract, the IAC column could recovery 94% and 88% target protein from the mixture. SDS-PAGE and Western blotting analysis confirmed the purified protein was Ara h 2, its purity reached about 90%. Significantly, the IAC column could capture dimer of Ara h 2, which made it feasible to prepared derivative of protein after processing.
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Albuminas 2S de Plantas/química , Albuminas 2S de Plantas/aislamiento & purificación , Anticuerpos/química , Antígenos de Plantas/química , Antígenos de Plantas/aislamiento & purificación , Arachis/química , Cromatografía de Afinidad/métodos , Glicoproteínas/química , Glicoproteínas/aislamiento & purificaciónRESUMEN
Antibodies are used extensively in numerous applications both in vivo and in vitro. To purify anti-Ara h 2 polyclonal antibody, a homemade immunoaffinity chromatography (IAC) column method was established. The properties of homemade column were compared with those of the mAb affinity protein G (MPG) agarose high flow, a commercially available column successfully used in capturing polyclonal antibodies. During antibody purification from rabbits' antiserum against Ara h 2, the column capacity, recovery, and purification factor were characterized for IAC and MPG. The homemade IAC could separate the corresponding antibody with higher specificity and lower cost but with lower recovery and column capacity than those of MPG. Thus, the homemade IAC is a specific, inexpensive, and suitable method that can be used for various laboratory purifications.
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Albuminas 2S de Plantas/inmunología , Anticuerpos/inmunología , Anticuerpos/aislamiento & purificación , Antígenos de Plantas/inmunología , Arachis/inmunología , Cromatografía de Afinidad/métodos , Glicoproteínas/inmunología , Animales , ConejosRESUMEN
BACKGROUND: This study examined technique characteristics of the immobilised Alcalase to hydrolyse egg white protein for potential allergenicity reduction. Alcalase was immobilised covalently on carboxyl-functionalised magnetic beads by carbodiimide activation. The technique characteristics of the immobilised Alcalase were investigated, followed by determining the degrees of hydrolysis (DH), immunoglobulin G (IgG) binding, and IgE binding of the digested egg white protein by immobilised Alcalase. RESULTS: Enzymatic activity, enzyme loading, and immobilisation yield of the prepared immobilised Alcalase were 20.55 U mg-1 , 925 mg g-1 , and 45%, respectively. Immobilised Alcalase showed maximum activity at pH 8.0 and 60 °C. Compared with free Alcalase, immobilised Alcalase exhibited better thermal and storage stability. Moreover, immobilised Alcalase can be reused 10 times and still maintained 55% of its initial activity. Partial hydrolysis of egg white protein by immobilised Alcalase can effectively reduce IgG and IgE binding of the hydrolysates. CONCLUSION: This study indicates that the immobilised Alcalase can be used to hydrolyse continuously egg white protein for potential allergenicity reduction. © 2016 Society of Chemical Industry.
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Proteínas del Huevo/inmunología , Proteínas del Huevo/metabolismo , Enzimas Inmovilizadas/metabolismo , Hipersensibilidad a los Alimentos/prevención & control , Subtilisinas/metabolismo , Estabilidad de Enzimas , Concentración de Iones de Hidrógeno , Hidrólisis , Interacciones Hidrofóbicas e Hidrofílicas , Inmunoglobulina E/metabolismo , Inmunoglobulina G/metabolismo , Hidrolisados de Proteína/inmunología , TemperaturaRESUMEN
BACKGROUND: Peanut is one of the eight major food allergens. Its allergen, Ara h 2, can be recognized by over 90% of serum IgE samples from peanut-allergic patients. Therefore, reducing the allergenicity of Ara h 2 is especially important. RESULTS: In the present study, polyphenol oxidase (PPO), a protein cross-linking reaction catalyst that acts on tyrosine residue, was used to modify Ara h 2. After crosslinking, the microstructure, digestibility, IgG binding capability and IgE binding capability of Ara h 2 were analyzed. Cross-linking decreased the potential allergenicity of Ara h 2 by masking the allergen epitope, while the antigenicity of Ara h 2 changed slightly. After crosslinking, the apparent diameter of Ara h 2 was altered from 300 to 1700 nm or 220 nm, indicating that polymerization could either be inter- or intramolecular. Regarding digestibility, crosslinked Ara h 2 was relatively more easily digested by gastric fluid compared with the untreated Ara h 2, but much more difficult in the intestinal fluid. CONCLUSION: The crosslinking reaction catalyzed by PPO, as a non-thermal process, may be beneficial for avoiding food allergy. The reaction could mask allergen epitopes, decreasing the allergenicity of Ara h 2. © 2015 Society of Chemical Industry.
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Albuminas 2S de Plantas/inmunología , Albuminas 2S de Plantas/metabolismo , Antígenos de Plantas/inmunología , Antígenos de Plantas/metabolismo , Arachis/inmunología , Arachis/metabolismo , Catecol Oxidasa/metabolismo , Glicoproteínas/inmunología , Glicoproteínas/metabolismo , Albuminas 2S de Plantas/química , Alérgenos/química , Alérgenos/inmunología , Alérgenos/metabolismo , Antígenos de Plantas/química , Digestión , Epítopos , Glicoproteínas/química , Humanos , Inmunoglobulina E/química , Unión Proteica , Estructura Secundaria de ProteínaRESUMEN
Quantification of certain protein contents in the matrix is essential in protein analyses. The amount of total protein in the matrix can be determined by the Kjeldahl method. However, few methods can quantify certain protein contents in the matrix without extracting all of them in solution. Extracting all of the contents is difficult for proteins, especially relatively insoluble ones. A five-step sequential extraction method was developed for the quantification of certain proteins in defatted peanut flour based on the relationship between the extracted protein contents and the extraction times. The extracted proteins (i.e., total protein, Ara h 1, and Ara h 2) were quantitatively analyzed in each extraction of the same condition. An exponential equation was obtained between the extraction times and the respective amount of extracted protein as well as both the total protein and a particular protein. In particular, the amount of protein extracted each time can be a geometric sequence. If all proteins can be extracted with sufficient extraction times, the protein contents in the peanut matrix can be calculated using a mathematical summation formula. This sum should be all proteins in the matrix. The five-step sequential extraction method can provide a means to quantify certain proteins in the matrix.
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Alérgenos/aislamiento & purificación , Arachis/química , Fraccionamiento Químico/métodos , Proteínas de Plantas/aislamiento & purificación , Electroforesis en Gel de Poliacrilamida , Ensayo de Inmunoadsorción EnzimáticaRESUMEN
Soybean proteins are widely used in many food products. However they also commonly cause food allergy. This study aimed to characterize the allergenicity of germinated soybean proteins in a BALB/c mouse model. Mice were orally sensitized with germinated soybean proteins or soybean proteins using cholera toxin as adjuvant. Anaphylactic shock reactions as well as changes in body temperature, specific antibody levels, mast cell protease-1 (mMCP-1) concentrations, morphological structure of duodenum, and cytokines were determined after the mice were challenged with germinated soybean proteins or soybean proteins. In contrast to soybean proteins, oral sensitization to germinated soybean proteins did not result in anaphylactic shock symptoms or decreased body temperature in mice. However, a minor damage of the intestinal villus existed after the challenge. A tendency toward decreased allergen-specific IgE, IgG and IgG1 levels, and mMCP-1 concentration was observed, accompanied by a repression of IL-4, IL-5, IL-13 and IFN-γ production in spleen cell cultures. Results indicate that germinated soybean proteins did not provoke remarkable allergic reactions compared to soybean proteins. Germinated soybean proteins have the potential to be a safe dietary formula for humans at risk of soybean allergy. However, additional studies on the underlying mechanisms and clinical trials are necessary.
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Anafilaxia/prevención & control , Hipersensibilidad a los Alimentos/prevención & control , Germinación , Proteínas de Soja/administración & dosificación , Administración Oral , Anafilaxia/sangre , Anafilaxia/etiología , Anafilaxia/inmunología , Animales , Temperatura Corporal , Quimasas/sangre , Citocinas/inmunología , Modelos Animales de Enfermedad , Duodeno/patología , Femenino , Hipersensibilidad a los Alimentos/sangre , Hipersensibilidad a los Alimentos/etiología , Hipersensibilidad a los Alimentos/inmunología , Inmunoglobulina E/sangre , Inmunoglobulina G/sangre , Ratones Endogámicos BALB C , Proteínas de Soja/efectos adversos , Bazo/inmunologíaRESUMEN
Reaction to peanut, as one of the major food allergens, has become an increasingly common life-threatening disorder. Although peanut allergens have been extensively identified, Ara h 1 is still too expensive to be applied in food safety or clinical utility. In this study, the purification, expression, and immunological analyses of Ara h 1 are investigated. It was shown that a high purity (>95%) of Ara h 1 could be prepared by either purification or expression. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), Western blot, and mass spectroscopy were used to identify the Ara h 1, and it was found that natural Ara h 1 (nAra h 1) and expressed Ara h 1 (rAra h 1) have the same properties, including amino acid sequence. In particular, rAra h 1 reacted positively with anti-nAra h 1 serum, showing their similar immunological property. Thus, by either purification or expression, Ara h 1 could be prepared with low cost, as performed in the present work. SDS-PAGE, mag trix-assisted laser desorption/ionization time-of-flight mass spectroscopy (MALDI-TOF MS), and immunological analysis confirmed that both forms of Ara h 1 had the same properties.
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Antígenos de Plantas/genética , Antígenos de Plantas/aislamiento & purificación , Glicoproteínas/genética , Glicoproteínas/aislamiento & purificación , Proteínas de Plantas/genética , Proteínas de Plantas/aislamiento & purificación , Animales , Antígenos de Plantas/inmunología , Western Blotting , Cromatografía de Afinidad , Electroforesis en Gel de Poliacrilamida , Ensayo de Inmunoadsorción Enzimática , Glicoproteínas/inmunología , Masculino , Proteínas de la Membrana , Proteínas de Plantas/inmunología , Conejos , Proteínas Recombinantes/genética , Proteínas Recombinantes/aislamiento & purificación , Espectrometría de Masa por Láser de Matriz Asistida de Ionización DesorciónRESUMEN
Allergic enteritis is an important phenotype of food allergies. However, there is not a suitable animal model for deeply exploring the natural progression and mechanism of allergic enteritis. In our study, we successfully developed an allergic enteritis animal model by feeding mice with an egg white diet. Following the dietary challenge, allergic mice displayed typical food allergy manifestations, including decreased core temperature, aversion to the allergenic diet, and elevated levels of serum sIgE and mMCP-1. Notably, these dietary challenged mice exhibited severe gut damage, characterized by disrupted intestinal microstructure, tissue inflammation, and edema that were evident morphologically. Moreover, upon exposure to food allergens, we observed a marked increase in caspase-3 and GSDMC levels in allergic mice. These two active proteins were found to be colocalized in damaged mucosal enterocytes and were associated with the secretion of epithelial sourced alarmins, such as IL25 and TSLP. Further data on the cellular and molecular levels suggest that such severe food-induced enteritis is mediated by the caspase-3-GSDMC pathway. We believe that this established animal model provides a valuable tool for advancing research on the mechanisms of food allergies.
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Given that roasted peanut (Ro) products are commonly used in daily life, peanut allergenicity is a foremost concern. Analyzing the changes in the structure and potential allergenicity of individual allergens can promote the exploration of the structural basis of the alterations in the potential allergenicity of Ro. This work focused on four major allergens in raw peanut (Ra) and Ro. Structural changes were analyzed on the basis of circular dichroism, ultraviolet and fluorescence spectroscopy, and molecular dynamic simulation. The IgE recognition capability of allergens was assessed via western blot analysis. The IgE binding capacity of allergens was detected by conducting enzyme-linked immunosorbent assay. The potential allergenicity of allergens was evaluated using the KU812 cell degranulation model. The results showed that roasting induced different changes in the overall structures of allergens and altered the structures and electrostatic potential of IgE epitopes, especially Ara h 1 and Ara h 6. These alterations affected the potential allergenicity of allergens. Ara h 1 and Ara h 6 in Ro showed significantly enhanced IgE binding capacities and abilities to elicit KU812 cell degranulation, while Ara h 2 and Ara h 3 did not change significantly. For total protein, the roasted peanut protein showed decreased abilities to elicit KU812 cell degranulation. The results indicated that different allergens in Ro showed different changes of structures and potential allergenicity and that the conformational structure plays a crucial role in potential allergenicity of allergens.
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Antígenos de Plantas , Hipersensibilidad al Cacahuete , Arachis/química , Inmunoglobulina E/metabolismo , Alérgenos/metabolismo , Proteínas de Plantas/química , Albuminas 2S de Plantas/químicaRESUMEN
Currently, food allergies are closely related to intestinal health, and ensuring the integrity and health of intestinal mucosa could reduce the incidence of food allergies. In this study, a soybean-allergic mouse model was used to explore the mechanism of intestinal mucosa immune response induced by enzyme-cross-linked tofu. The effects of enzyme-cross-linked tofu on intestinal mucosal immunity in mice were determined by hematoxylin-eosin (HE) staining and flow cytometry. Our results reveled that the MTG-cross-linked tofu reduced the reactivity of the intestinal mucosal immune system, which mainly manifested as a decrease in the dendritic cell (DC) levels of mesenteric lymph nodes (MLNs), increasing the Th1 cells and Tregs in Peyer's patch (PP) nodes and MLNs, and inhibiting the Th2 cells. Compared with soy protein, enzyme-cross-linked tofu had less damage to the small intestinal tract of mice. Therefore, the above-mentioned results fully revealed that the enzyme-cross-linked tofu promoted the transformation of intestinal mucosal immune cells, shifted the Th1/Th2 balance toward Th1, and reduced its sensitization effect.
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Casein, the major allergen in cow's milk, presents a significant challenge in providing nutritional support for children with allergies. To address this issue, we investigated a composite enzyme, comprising papain and chymotrypsin, to reduce the allergenicity of casein. Enzymatic hydrolysis induced substantial structural changes in casein, diminishing its affinity for specific IgE and IgG antibodies. Additionally, in a BALB/c mouse model, casein hydrolysate alleviated allergic symptoms, evidenced by lower serum IgE and IgG levels, reduced plasma histamine, and decreased Th2 cytokine release during cell co-culture. Peptidomic analysis revealed a 52.38% and 60% reduction in peptides containing IgE epitopes in casein hydrolyzed by the composite enzyme compared to papain and chymotrypsin, respectively, along with a notable absence of previously reported T cell epitopes. These results demonstrate the potential of enzyme combinations to enhance the efficiency of epitope destruction in allergenic proteins, providing valuable insights into the development of hypoallergenic dairy products.