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1.
J Agric Food Chem ; 72(20): 11746-11758, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38718253

RESUMO

A novel strategy combining ferulic acid and glucose was proposed to reduce ß-lactoglobulin (BLG) allergenicity and investigate whether the reduction in allergenicity was associated with gut microbiome and serum metabolism. As a result, the multistructure of BLG changed, and the modified BLG decreased significantly the contents of IgE, IgG, IgG1, and mMCP-1 in serum, improved the diversity and structural composition of gut microbiota, and increased the content of short-chain fatty acids (SCFAs) in allergic mice. Meanwhile, allergic mice induced by BLG affected arachidonic acid, tryptophan, and other metabolic pathways in serum, the modified BLG inhibited the production of metabolites in arachidonic acid metabolism pathway and significantly increased tryptophan metabolites, and this contribution helps in reducing BLG allergenicity. Overall, reduced allergenicity of BLG after ferulic acid was combined with glucose modification by regulating gut microbiota, the metabolic pathways of arachidonic acid and tryptophan. The results may offer new thoughts alleviating the allergy risk of allergenic proteins.


Assuntos
Alérgenos , Ácidos Cumáricos , Microbioma Gastrointestinal , Glucose , Lactoglobulinas , Ácidos Cumáricos/metabolismo , Ácidos Cumáricos/química , Animais , Lactoglobulinas/imunologia , Lactoglobulinas/química , Lactoglobulinas/metabolismo , Camundongos , Humanos , Alérgenos/imunologia , Alérgenos/química , Alérgenos/metabolismo , Glucose/metabolismo , Feminino , Bactérias/imunologia , Bactérias/metabolismo , Bactérias/classificação , Bactérias/genética , Camundongos Endogâmicos BALB C , Imunoglobulina E/imunologia , Imunoglobulina E/sangue , Ácidos Graxos Voláteis/metabolismo , Bovinos , Imunoglobulina G/imunologia , Imunoglobulina G/sangue , Hipersensibilidade a Leite/imunologia
2.
Int J Biol Macromol ; 268(Pt 1): 131773, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38657930

RESUMO

The antigenicity of ß-lactoglobulin (ß-LG) can be influenced by pH values and reduced by epigallocatechin-3-gallate (EGCG). However, a detailed mechanism concerning EGCG decreasing the antigenicity of ß-LG at different pH levels lacks clarity. Here, we explore the inhibition mechanism of EGCG on the antigenicity of ß-LG at pH 6.2, 7.4 and 8.2 using enzyme-linked immunosorbent assay, multi-spectroscopy, mass spectrometry and molecular simulations. The results of Fourier transform infrared spectroscopy (FTIR) and circular dichroism (CD) elucidate that the noncovalent binding of EGCG with ß-LG induces variations in the secondary structure and conformations of ß-LG. Moreover, EGCG inhibits the antigenicity of ß-LG the most at pH 7.4 (98.30 %), followed by pH 6.2 (73.18 %) and pH 8.2 (36.24 %). The inhibitory difference is attributed to the disparity in the number of epitopes involved in the interacting regions of EGCG and ß-LG. Our findings suggest that manipulating pH conditions may enhance the effectiveness of antigenic inhibitors, with the potential for further application in the food industry.


Assuntos
Catequina , Lactoglobulinas , Lactoglobulinas/química , Lactoglobulinas/imunologia , Catequina/análogos & derivados , Catequina/química , Catequina/farmacologia , Concentração de Íons de Hidrogênio , Simulação de Dinâmica Molecular , Estrutura Secundária de Proteína , Dicroísmo Circular , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Simulação de Acoplamento Molecular , Antígenos/imunologia , Antígenos/química
3.
Food Funct ; 12(22): 11343-11350, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34668899

RESUMO

Epigallocatechin gallate (EGCG) and ß-lactoglobulin (ßLg) were conjugated by covalent bonds to form EGCG-ßLg conjugates. This conjugation causes structural and bioactivity changes in ßLg, which in turn can be used as a possible approach for desensitization to allergens. In this study, the desensitization mechanism was investigated by monitoring ßLg secondary structure and immunoglobulin E (IgE) combining capacity changes on the basis of the conjugation mechanism. Furthermore, the desensitization efficiency in vivo was evaluated through animal experiments. The results show that temperature influenced the conjugation by decreasing the binding affinities (Ka) and binding numbers (n) of EGCG. The conjugation of EGCG decreased ßLg's IgE combining capacity by decreasing the ß-sheet component and imparted antioxidant properties by the introduction of hydroxyl groups. In addition, animal experiment results indicated that ßLg induced significant changes in the levels of IgE and inflammatory cytokines, and the relative abundance of small intestinal flora, linked to the inflammatory lesions and anaphylaxis symptoms. EGCG-ßLg conjugates can suppress the allergic response, attenuating serum IgE and relieving the anaphylaxis symptoms.


Assuntos
Catequina/análogos & derivados , Dessensibilização Imunológica , Lactoglobulinas , Alérgenos/imunologia , Animais , Catequina/química , Catequina/imunologia , Catequina/farmacologia , Feminino , Microbioma Gastrointestinal/efeitos dos fármacos , Microbioma Gastrointestinal/imunologia , Tolerância Imunológica/imunologia , Imunoglobulina E/imunologia , Lactoglobulinas/química , Lactoglobulinas/imunologia , Lactoglobulinas/farmacologia , Camundongos , Camundongos Endogâmicos BALB C
4.
Food Funct ; 12(20): 10107-10120, 2021 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-34522929

RESUMO

Currently, there is a need to explore the effects of different types of protein-anthocyanin complexations, as well as the possible changes in the nutrition and allergenicity of the formed complexes. Here, we systematically investigated the covalent and non-covalent interactions between cyanidin-3-O-glucoside (C3G) and two major milk proteins, α-casein (α-CN) and ß-lactoglobulin (ß-LG). Fluorescence quenching data showed that, under non-covalent conditions, C3G quenched the fluorescence of the two proteins via a static process, with the interaction forces being revealed; for covalent products, decreased fluorescence intensities were observed with red shifts in the λmax. Multiple spectroscopic analyses implied that C3G-addition induced protein structural unfolding through transitions between the random coil and ordered secondary components. With a two-stage simulated gastrointestinal (GI) digestion model, it was seen that covalent complexes, not their non-covalent counterparts, showed reduced protein digestibility, ascribed to structural changes resulting in the unavailability of enzyme cleaving sites. The GI digests displayed prominent 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation-scavenging abilities (3.8-11.1 mM Trolox equivalents per mL digest), in contrast to the markedly reduced 1,1-diphenyl-2-picrylhydrazyl radical-scavenging capacities. Additionally, covalent protein-C3G complexes, but not their non-covalent counterparts, showed lower IgE-binding levels in comparison to the native control. This study provides new understanding for the development of anthocyanin-milk protein systems as functional ingredients with health-beneficial properties.


Assuntos
Alérgenos/imunologia , Antocianinas/química , Caseínas/química , Lactoglobulinas/química , Animais , Antocianinas/imunologia , Antocianinas/metabolismo , Caseínas/imunologia , Caseínas/metabolismo , Digestão , Difusão Dinâmica da Luz/métodos , Humanos , Imunoglobulina E/química , Imunoglobulina E/imunologia , Lactoglobulinas/imunologia , Lactoglobulinas/metabolismo , Proteínas do Leite/química , Proteínas do Leite/imunologia , Proteínas do Leite/metabolismo , Tamanho da Partícula , Ligação Proteica , Conformação Proteica , Espectrometria de Fluorescência/métodos
5.
Nutrients ; 13(9)2021 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-34578889

RESUMO

Human clinical trials have shown that a specific partially hydrolyzed 100% whey-based infant formula (pHF-W) reduces AD risk in the first yeast of life. Meta-analyses with a specific pHF-W (pHF-W1) confirm a protective effect while other meta-analyses pooling different pHF-W show conflicting results. Here we investigated the molecular composition and functional properties of the specific pHF-W1 as well as the stability of its manufacturing process over time. This specific pHF-W1 was compared with other pHF-Ws. We used size exclusion chromatography to characterize the peptide molecular weight (MW), a rat basophil degranulation assay to assess the relative level of beta-lactoglobulin (BLG) allergenicity and a preclinical model of oral tolerance induction to test prevention of allergic sensitization. To analyze the exact peptide sequences before and after an HLA binding assay, a mass cytometry approach was used. Peptide size allergenicity and oral tolerance induction were conserved across pHF-W1 batches of production and time. The median MW of the 37 samples of pHF-W1 tested was 800 ± 400 Da. Further oral tolerance induction was observed using 10 different batches of the pHF-W1 with a mean reduction of BLG-specific IgE levels of 0.76 log (95% CI = -0.95; -0.57). When comparing pHF-W1 with three other formulas (pHF-W2 3 and 4), peptide size was not necessarily associated with allergenicity reduction in vitro nor oral tolerance induction in vivo as measured by specific IgE level (p < 0.05 for pHF-W1 and 2 and p = 0.271 and p = 0.189 for pHF-W3 and 4 respectively). Peptide composition showed a limited overlap between the formulas tested ranging from 11.7% to 24.2%. Furthermore nine regions in the BLG sequence were identified as binding HLA-DR. In conclusion, not all pHF-Ws tested have the same peptide size distribution decreased allergenicity and ability to induce oral tolerance. Specific peptides are released during the different processes used by different infant formula producers.


Assuntos
Alérgenos , Fórmulas Infantis/análise , Lactoglobulinas , Hipersensibilidade a Leite , Peptídeos , Proteínas do Soro do Leite , Alérgenos/imunologia , Animais , Cromatografia , Dermatite Atópica , Indústria Alimentícia , Alimentos Formulados , Humanos , Hidrólise , Imunoglobulina E , Lactente , Lactoglobulinas/análise , Lactoglobulinas/imunologia , Hipersensibilidade a Leite/prevenção & controle , Proteínas do Leite , Peso Molecular , Peptídeos/análise , Peptídeos/imunologia , Hidrolisados de Proteína/análise , Hidrolisados de Proteína/imunologia , Ratos Sprague-Dawley , Soro do Leite , Proteínas do Soro do Leite/análise , Proteínas do Soro do Leite/imunologia
6.
Front Immunol ; 12: 611474, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33746954

RESUMO

The lipocalin beta-lactoglobulin (BLG) is a major protein compound in cow's milk, and we detected it in cattle stable dust. BLG may be a novel player in the farm protective effect against atopic sensitization and hayfever. In previous studies, we demonstrated that only the ligand-filled holo-form of BLG prevented sensitization to itself. Here, we investigated whether holo-BLG could, in an innate manner, also protect against allergic sensitization to unrelated birch pollen allergens using a murine model. BALB/c mice were nasally pretreated four times in biweekly intervals with holo-BLG containing quercetin-iron complexes as ligands, with empty apo-BLG, or were sham-treated. Subsequently, mice were intraperitoneally sensitized two times with apo-BLG or with the unrelated birch pollen allergen apo-Bet v 1, adjuvanted with aluminum hydroxide. After subsequent systemic challenge with BLG or Bet v 1, body temperature drop was monitored by anaphylaxis imaging. Specific antibodies in serum and cytokines of BLG- and Bet v 1-stimulated splenocytes were analyzed by ELISA. Additionally, human peripheral blood mononuclear cells of pollen allergic subjects were stimulated with apo- versus holo-BLG before assessment by FACS. Prophylactic treatment with the holo-BLG resulted in protection against allergic sensitization and clinical reactivity also to Bet v 1 in an unspecific manner. Pretreatment with holo-BLG resulted in significantly lower BLG-as well as Bet v 1-specific antibodies and impaired antigen-presentation with significantly lower numbers of CD11c+MHCII+ cells expressing CD86. Pretreatment with holo-BLG also reduced the release of Th2-associated cytokines from Splenocytes in BLG-sensitized mice. Similarly, in vitro stimulation of PBMCs from birch pollen allergic subjects with holo-BLG resulted in a relative decrease of CD3+CD4+ and CD4+CRTh2 cells, but not of CD4+CD25+CD127- Treg cells, compared to apo-BLG stimulation. In conclusion, prophylactic treatment with holo-BLG protected against allergy in an antigen-specific and -unspecific manner by decreasing antigen presentation, specific antibody production and abrogating a Th2-response. Holo-BLG therefore promotes immune resilience against pollen allergens in an innate manner and may thereby contribute to the farm protective effect against atopic sensitization.


Assuntos
Alérgenos/imunologia , Proteção Cruzada/imunologia , Lactoglobulinas/imunologia , Pólen/imunologia , Rinite Alérgica Sazonal/imunologia , Rinite Alérgica Sazonal/prevenção & controle , Administração Intranasal , Animais , Especificidade de Anticorpos , Apresentação de Antígeno/imunologia , Bovinos , Citocinas/metabolismo , Feminino , Imunização Passiva , Imunoglobulina E/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Lactoglobulinas/administração & dosagem , Camundongos , Pólen/efeitos adversos , Células Th2/imunologia , Células Th2/metabolismo
7.
Mol Nutr Food Res ; 65(8): e2000834, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33559978

RESUMO

SCOPE: ß-lactoglobulin (BLG) is a major cow milk allergen encountered by the immune system of infants fed with milk-based formulas. To determine the effect of processing on immunogenicity of BLG, this article characterized how heated and glycated BLG are recognized and internalized by APCs. Also, the effect of heat-induced structural changes as well as gastrointestinal digestion on immunogenicity of BLG is evaluated. METHODS AND RESULTS: The binding and uptake of BLG from raw cow milk and heated either alone (BLG-H) or with lactose/glucose (BLG-Lac and BLG-Glu) to the receptors present on APCs are analyzed by ELISA and cell-binding assays. Heated and glycated BLG is internalized via galectin-3 (Gal-3)and scavenger receptors (CD36 and SR-AI) while binding to the receptor for advanced glycation end products (R AGE) does not cause internalization. Receptor affinity of BLG is dependent on increased hydrophobicity, ß-sheet exposure and aggregation. Digested glycated BLG maintained binding to sRAGE and Gal-3 but not to CD36 and SR-AI, and is detected on the surface of APCs. This suggests a mechanism via which digested glycated BLG may trigger innate (via RAGE) and adaptive immunity (via Gal-3). CONCLUSIONS: This study defines structural characteristics of heated and glycated BLG determining its interaction with APCs via specific receptors thus revealing enhanced immunogenicity of glycated versus heated BLG.


Assuntos
Células Apresentadoras de Antígenos/metabolismo , Lactoglobulinas/imunologia , Lactoglobulinas/metabolismo , Animais , Antígenos de Neoplasias/metabolismo , Proteínas Sanguíneas/metabolismo , Antígenos CD36/metabolismo , Digestão , Endocitose/fisiologia , Manipulação de Alimentos , Galectinas/metabolismo , Humanos , Lactente , Lactoglobulinas/química , Lactoglobulinas/farmacocinética , Macrófagos/metabolismo , Leite/química , Hipersensibilidade a Leite/imunologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Receptores Depuradores Classe A/metabolismo
8.
Food Chem ; 350: 129139, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-33588281

RESUMO

ß-Lactoglobulin (ß-LG) is one of the major food allergens. Enzymatic hydrolysis is a promising strategy to reduce the antigenicity of ß-LG in industrial production. The relationship between the cleavage sites of ß-LG by protease and its antigenic active sites were explored in this study. Molecular docking and molecular dynamics (MD) were used to analyze the active sites and interaction force of ß-LG and IgG antibody. Whey protein was hydrolyzed by four specific enzymes and the antigenicity of the hydrolysates were determined by ELISA. The results of MD showed that the amino acid residue Gln155 (-4.48 kcal mol-1) played the most important roles in the process of binding. Hydrolysates produced by AY-10, which was the only one with specificity towards cleavage sites next to a Gln, had the lowest antigenicity at the same hydrolysis degree. Antigenicity decrease was related to the energy contribution of the cleavage site in the active sites.


Assuntos
Lactoglobulinas/imunologia , Lactoglobulinas/metabolismo , Simulação de Dinâmica Molecular , Peptídeo Hidrolases/metabolismo , Animais , Domínio Catalítico , Hidrólise , Imunoglobulina G/imunologia , Lactoglobulinas/química , Simulação de Acoplamento Molecular , Proteínas do Soro do Leite/metabolismo
9.
Food Chem ; 343: 128402, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33406572

RESUMO

A new method was investigated to decline the antigenicity of ß-Lactoglobulin (ß-LG) by site specifically conjugating ß-LG at the N-terminus with 5 kDa and 10 kDa monomethoxy polyethylene glycol propyl aldehyde (mPEG-ALD). The optimal reaction conditions were molar ratio of 1:10 (ß-LG:mPEG-ALD), reaction time for 16 h, and pH 5.0, and the content of mono-PEGylated ß-LG was 51.3%. The results showed that mono-PEGylated ß-LG with molecular mass of 23.2 kDa and 28.5 kDa. The peptide fragments of mPEG5kDa-ALD-ß-LG produced the same sequence pattern of ß-LG except for the absence of one peptides f(1-14), indicating that α-amino group at the N-terminal was selectively modified. Furthermore, the conformation of modified ß-LG underwent into slight change. The antigenicity of mPEG5kDa-ALD-ß-LG and mPEG10kDa-ALD-ß-LG decreased from 144.4 µg/mL to 66.7 and 39.0 µg/mL respectively. It was speculated that the steric hindrance effect of PEG was the main reason for the decline of antigenicity of ß-LG.


Assuntos
Lactoglobulinas/química , Polietilenoglicóis/química , Animais , Antígenos/química , Antígenos/imunologia , Bovinos , Ensaio de Imunoadsorção Enzimática , Lactoglobulinas/imunologia , Peso Molecular , Estrutura Quaternária de Proteína , Estrutura Secundária de Proteína , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
10.
Nutrients ; 13(2)2021 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-33503831

RESUMO

The presence of various proteins, including modified ones, in food which exhibit diverse immunogenic and sensitizing properties increases the difficulty of predicting host immune responses. Still, there is a lack of sufficiently reliable and comparable data and research models describing allergens in dietary matrices. The aim of the study was to estimate the immunomodulatory effects of ß-lactoglobulin (ß-lg) in comparison to those elicited by κ-casein (κ-CN), in vivo and ex vivo, using naïve splenocytes and a mouse sensitization model. Our results revealed that the humoral and cellular responses triggered by ß-lg and κ-CN were of diverse magnitudes and showed different dynamics in the induction of control mechanisms. ß-Lg turned out to be more immunogenic and induced a more dominant Th1 response than κ-CN, which triggered a significantly higher IgE response. For both proteins, CD4+ lymphocyte profiles correlated with CD4+CD25+ and CD4+CD25+Foxp3+ T cells induction and interleukin 10 secretion, but ß-lg induced more CD4+CD25+Foxp3- Tregs. Moreover, ex vivo studies showed the risk of interaction of immune responses to different milk proteins, which may exacerbate allergy, especially the one caused by ß-lg. In conclusion, the applied model of in vivo and ex vivo exposure to ß-lg and κ-CN showed significant differences in immunoreactivity of the tested proteins (κ-CN demonstrated stronger allergenic potential than ß-lg), and may be useful for the estimation of allergenic potential of various food proteins, including those modified in technological processes.


Assuntos
Caseínas/imunologia , Lactoglobulinas/imunologia , Hipersensibilidade a Leite/imunologia , Linfócitos T/imunologia , Animais , Modelos Animais de Doenças , Feminino , Camundongos , Camundongos Endogâmicos BALB C
11.
Int Immunol ; 33(3): 183-189, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33027513

RESUMO

Food allergy is a common disease caused by intake of allergen-containing foods, such as milk, eggs, peanuts and wheat. Systemic anaphylaxis is a severe hypersensitive allergic reaction resulting from degranulation of mast cells or basophils after cross-linking of surface high-affinity IgE receptors (Fcε-RI) with allergen-specific IgE and allergens. In this study, we developed a novel human mast cell/basophil-engrafted mouse model that recapitulates systemic anaphylaxis triggered by ß-lactoglobulin (BLG), a major allergen found in cow's milk. Human CD34+ hematopoietic stem cells were transferred into NOG (non-Tg) or NOG hIL-3/hGM-CSF transgenic (Tg) mice. After 14-16 weeks, bovine BLG-specific human IgE was intravenously injected into humanized mice, followed by intravenous or oral bovine BLG exposure 1 day later. Body temperature in Tg, but not in non-Tg, mice gradually decreased within 10 min, and 80% of Tg mice died within 1 h by intravenous BLG exposure. Serum histamine levels and anaphylaxis scores in Tg mice were markedly increased compared to non-Tg mice. Furthermore, these allergic symptoms were significantly inhibited by epinephrine treatment of the Tg mice. Therefore, the current NOG hIL-3/hGM-CSF Tg mouse model may be useful for development of novel anaphylaxis drugs for treatment of food allergies and for safety assessment of low-allergenicity extensively hydrolyzed cow's milk whey protein-based infant formulas.


Assuntos
Anafilaxia/imunologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/genética , Imunoglobulina E/imunologia , Lactoglobulinas/imunologia , Hipersensibilidade a Leite/imunologia , Anafilaxia/mortalidade , Animais , Basófilos/imunologia , Bovinos , Modelos Animais de Doenças , Epinefrina/uso terapêutico , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Transplante de Células-Tronco Hematopoéticas , Células-Tronco Hematopoéticas , Histamina/sangue , Humanos , Interleucina-3/genética , Interleucina-3/metabolismo , Mastócitos/imunologia , Camundongos , Camundongos Endogâmicos NOD , Camundongos Transgênicos
12.
Food Chem ; 339: 128106, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33152886

RESUMO

It is practical to inhibit the allergenicity of ß-lactoglobulin (ß-LG) using natural products acting via noncovalent interactions; however, the mechanism of the effect has not been investigated in detail. Herein, the comprehensive noncovalent mechanism of inhibition of the antigenicity of ß-LG by six flavonoids (kaempferol, myricetin, phloretin, epigallocatechin-3-gallate (EGCG), naringenin, and quercetin) was investigated by spectroscopic and molecular docking methods. Our results indicate that six flavonoids reduced the antigenicity of ß-LG in the following order: EGCG > phloretin > naringenin > myricetin > kaempferol > quercetin, with antigenic inhibition rates of 72.6%, 68.4%, 59.7%, 52.3%, 51.4% and 40.8%, respectively. Six flavonoids induced distinct conformational changes in ß-LG, which were closely associated with a decline in antigenicity of ß-LG. The flavonoids bound to specific antigen epitopes in the ß-sheet and ß-turn of ß-LG to induce a decrease in the antigenicity of the protein.


Assuntos
Flavonoides/farmacologia , Lactoglobulinas/química , Lactoglobulinas/imunologia , Alérgenos/química , Alérgenos/imunologia , Alérgenos/metabolismo , Dicroísmo Circular , Epitopos/metabolismo , Flavonoides/química , Flavonoides/metabolismo , Lactoglobulinas/metabolismo , Simulação de Acoplamento Molecular , Conformação Proteica , Espectrometria de Fluorescência , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral
13.
Methods Mol Biol ; 2223: 67-78, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33226587

RESUMO

Cow's milk allergy is one of the most prevalent food allergies in both children and adults. As dairy products are common dietary ingredients and the prevalence of chronic conditions is on the rise, milk allergy is a growing public health concern. To elucidate underlying mechanisms and develop therapeutic strategies, reliable animal models are essential research tools. Sensitization to a milk protein is the principal procedure for establishing animal models of cow's milk allergy. However, the methods of sensitization vary from laboratory to laboratory, using different milk proteins with different amounts, routes, and durations of allergen exposure during sensitization of varying sex and strains of mice, likely resulting in diverse immunological and physical responses. Furthermore, the sources and potential impurities of milk protein may also produce variable responses. Thus, standardization of sensitization protocol is important, particularly when results are compared across studies. Here, we describe a method to generate a mouse model of cow's milk allergy using purified ß-lactoglobulin as the milk allergen with cholera toxin as an adjuvant in a 5-week oral sensitization protocol.


Assuntos
Anafilaxia/imunologia , Modelos Animais de Doenças , Lactoglobulinas/imunologia , Hipersensibilidade a Leite/imunologia , Leite/imunologia , Adjuvantes Imunológicos/administração & dosagem , Administração Oral , Alérgenos/administração & dosagem , Alérgenos/imunologia , Anafilaxia/sangue , Anafilaxia/patologia , Animais , Bovinos , Toxina da Cólera/administração & dosagem , Feminino , Humanos , Imunoglobulina E/sangue , Imunoglobulina E/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Lactoglobulinas/administração & dosagem , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Leite/efeitos adversos , Hipersensibilidade a Leite/sangue , Hipersensibilidade a Leite/patologia
14.
Methods Mol Biol ; 2223: 159-167, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33226594

RESUMO

Type-I hypersensitivity is commonly characterized by increased levels of antigen-specific immunoglobulin (Ig) E. Therefore, it is important for clinical and research investigators to reliably measure serum levels of IgE in allergic patients and animal models. While current ELISA-based methods are simple and commonly performed for the detection of allergen-specific IgE using serum or plasma, they may produce misleading results. This is in part due to decreased sensitivity for IgE in the presence of other Ig isotypes in the same sample, such as IgG, that are typically more abundant than IgE. When assessment of multiple Ig isotypes is necessary, performing optimized assays for individual isotypes requires high sample volumes. Here, we describe an approach to increase the sensitivity for IgE detection while conserving the sample volume needed. This method not only improves the accuracy of serum IgE measurements but also allows simultaneous analysis of other allergen-specific immunoglobulins.


Assuntos
Proteínas de Bactérias/metabolismo , Ensaio de Imunoadsorção Enzimática/métodos , Imunoglobulina E/sangue , Imunoglobulina G/isolamento & purificação , Separação Imunomagnética , Hipersensibilidade a Leite/sangue , Animais , Biotina/química , Peroxidase do Rábano Silvestre/química , Imunoglobulina G/sangue , Lactoglobulinas/administração & dosagem , Lactoglobulinas/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Hipersensibilidade a Leite/etiologia , Hipersensibilidade a Leite/imunologia , Ligação Proteica , Estreptavidina/química
17.
Allergol Immunopathol (Madr) ; 48(6): 666-674, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33131977

RESUMO

OBJECTIVES: The differences in the expression profiles of colonic miRNAs between ß-lactoglobulin (ß-Lg) allergic mice and normal mice were analyzed to investigate the important role of the miRNA regulation mechanism in the pathogenesis of cow's milk allergy. METHODS: The present study performed Illumina sequencing to characterize the miRNA profile changes in mouse colon responding to ß-Lg challenge. Target genes were predicted by TargetScan 50 and miRanda 3.3a algorithms and assessed by GO and KEGG analysis. The expression levels of selected miRNAs and cytokine production were verified by cell transfection and quantitative RT-PCR. RESULTS: A total of 15 miRNAs were diversely expressed between the colon of the normal and ß-Lg-sensitized mice (P < 0.05, fold change of >1.50 or <0.67), including six up-regulated miRNAs and nine down-regulated miRNAs, among which seven miRNAs were validated using qRT-PCR. GO enrichment and KEGG pathway analyses further revealed that biological process, protein binding, cytoplasm and the pathways of cancer were significantly enriched, which were closely connected to the allergic inflammation development. Additionally, six key functional interaction pairs in ß-Lg allergy were identified in miRNA prediction algorithms and verified using qRT-PCR. CONCLUSIONS: We can conclude that our results suggested that the miRNAs regulation network participated in the pathogenesis of cow's milk allergy.


Assuntos
Colo/patologia , Redes Reguladoras de Genes/imunologia , Lactoglobulinas/efeitos adversos , MicroRNAs/metabolismo , Hipersensibilidade a Leite/genética , Animais , Colo/imunologia , Citocinas/genética , Modelos Animais de Doenças , Feminino , Perfilação da Expressão Gênica , Humanos , Mucosa Intestinal/imunologia , Mucosa Intestinal/patologia , Lactoglobulinas/imunologia , Camundongos , Hipersensibilidade a Leite/imunologia
18.
Food Funct ; 11(10): 9240-9251, 2020 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-33034612

RESUMO

Bovine α-lactalbumin (BLA) and ß-lactoglobulin (BLG) are the most common and severe food allergens in milk and they can bind C18 unsaturated fatty acids (UFAs) and their bioactivities were changed. This study aims to determine the effects of C18 UFAs on the structures of BLA and BLG and their allergic properties, such as antigenicity and allergenicity. We reveal that C18 UFAs can efficiently promote the gradual unfolding of the structures of BLA and BLG and increase their hydrophobicity. Moreover, the IgG binding ability and the expression of IgG-dependent activation marker CD200R3 on basophils were remarkably promoted after C18 UFA treatment. Finally, we also observed that C18 UFAs can enhance the IgE binding ability and the degranulation capacity of human basophil KU812 cells (intracellular Ca2+, histamine, ß-Hex, and IL-6). Collectively, these results suggested that C18 UFAs changed the structures of BLA and BLG, which contributed to their increased allergic potential.


Assuntos
Ácidos Graxos Insaturados/química , Lactalbumina/química , Lactalbumina/imunologia , Lactoglobulinas/química , Lactoglobulinas/imunologia , Animais , Basófilos/imunologia , Bovinos , Humanos , Interações Hidrofóbicas e Hidrofílicas , Imunoglobulina E/imunologia , Imunoglobulina G/imunologia , Leite/química , Leite/imunologia , Hipersensibilidade a Leite/imunologia , Ligação Proteica , Conformação Proteica , Desdobramento de Proteína
19.
Int J Biol Macromol ; 164: 1527-1535, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32738325

RESUMO

ß-lactoglobulin (ß-Lg) was treated through different ultrasonic power and subsequently glycated with galactose to investigate its structural changes and immunological properties, and then evaluated by high-resolution mass spectrometry, enzyme-linked immunosorbent assay and basophil histamine release test. Ultrasonication combined with glycation (UCG) modification significantly reduced the IgE/IgG-binding capacity, and the release of ß-hexosaminidase, histamine and interleukin-6, accompanied with changes in the secondary and tertiary structures. The decrease in the allergenicity of ß-Lg depended not only on the glycation of K47, 60, 83, 91 and 135 within the linear epitopes, but also on the denaturation of conformational epitopes, which was supported by the glycation-induced alterations of the secondary and tertiary structures. This study confirmed that UCG modification is a promising method for decreasing the allergenic potential of allergic proteins, which is likely to develop a practical technology to produce hypo-allergenic milk.


Assuntos
Alérgenos/imunologia , Lactoglobulinas/imunologia , Animais , Linhagem Celular , Ensaio de Imunoadsorção Enzimática/métodos , Epitopos/imunologia , Glicosilação , Histamina/imunologia , Imunoglobulina E/imunologia , Imunoglobulina G/imunologia , Interleucina-6/imunologia , Espectrometria de Massas/métodos , Leite/imunologia , Ratos , Sonicação/métodos , Ultrassom/métodos , beta-N-Acetil-Hexosaminidases/imunologia
20.
Front Immunol ; 11: 1545, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32849523

RESUMO

Background: The high incidence of food allergy in childhood points to the need of elucidating early life factors dictating allergy susceptibility. Here, we aim to address in a mouse model how the exposure to a major cow's milk allergen through breastmilk of mothers with different immune status influences food allergy outcome in offspring. Methods: BALB/cJ future dams were either kept naïve, or sensitized through the oral route using cholera toxin ("orally sensitized") or through the i.p. route using alum ("i.p. sensitized"), or rendered fully tolerant (oral gavage without any adjuvant) to bovine ß-lactoglobulin (BLG). After mating with naïve males and delivery, mothers were orally exposed or not to BLG during the whole lactation. Then, eight groups of lactating mothers were considered: naïve, i.p. sensitized, orally sensitized, or tolerant, each exposed or not during lactation. In order to specifically address breastmilk effects on their allergy susceptibility, pups from naïve-synchronized mothers were cross-fostered by the different groups of treated dams and lactating mothers at delivery. In some experiments, mothers kept their own pups to address a possible in utero effect. BLG antigen, BLG-specific antibodies, and BLG-immune complexes were measured in breastmilk from the different lactating mother groups. Allergic sensitization was monitored in 5-weeks old female offspring (n = 7-8/group of lactating mothers) by determining BLG-specific antibodies in plasma and splenocytes cytokine secretion after i.p. injections of BLG/alum. Allergic reaction to oral BLG challenge was evaluated by measuring mMCP1 in plasma. Results: Offspring was protected from one allergic i.p. sensitization when nursed by i.p. sensitized mothers, independently of BLG exposure during lactation. Orally sensitized dams conferred protection in offspring solely when exposed to BLG during lactation, while naïve mothers did not provide any protection upon BLG exposure. The levels of protection correlated with the levels of BLG-specific antibodies and BLG-immune complex in breastmilk. There was a trend for decreased sensitization in offspring breastfed by tolerant and exposed mothers, which was not associated with transfer of specific antibodies through breastmilk. Protection provided by nursing by treated/exposed mothers was not persistent after a boost i.p. injection of the progeny and then did not protect them from an allergic reaction induced at this time point. No additional in utero effects were evidenced. Conclusion: Our study demonstrates the strong potential of breastmilk to modulate immune response to a major cow's milk allergen in the progeny. It highlights the importance of maternal immune status and of her consumption of the allergen during lactation in dictating the outcomes in offspring. This opens perspectives where modulating maternal immune status might increase the chance of cow's milk allergy prevention in breastfed children.


Assuntos
Alérgenos/imunologia , Aleitamento Materno , Imunidade Materno-Adquirida , Hipersensibilidade a Leite/imunologia , Hipersensibilidade a Leite/prevenção & controle , Animais , Anticorpos/imunologia , Bovinos , Citocinas/metabolismo , Feminino , Humanos , Imunoglobulina E/imunologia , Imunoglobulina G/imunologia , Lactação , Lactoglobulinas/imunologia , Masculino , Camundongos , Gravidez
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