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1.
J Agric Food Chem ; 72(31): 17549-17558, 2024 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-39054671

RESUMEN

ß-Lactoglobulin (ßLG) is a major allergen in bovine milk protein. This study was designed to investigate changes in ßLG structure, digestibility, and allergenicity induced by covalent binding modification with different contents of (-)-epigallocatechin 3-gallate (EGCG). The reaction of EGCG conjugation with ßLG reached saturation at a molar ratio of 1:60 ßLG:EGCG. Conjugation with EGCG altered the ßLG structure, decreased IgE-binding capacity, and increased digestibility in a dose-dependent manner. In vivo studies showed that covalent conjugation with EGCG can reduce ßLG-induced allergic symptoms with reducing levels of IgE, histamine, and mast cell protease-1 (mMCP-1) and the percentage of sensitized mast cells. Allergenicity was reduced more effectively in saturated ßLG-EGCG conjugates compared to semisaturated conjugates. Observed changes in IFN-γ, IL-4, IL-5, IL-10, and TGF-ß levels suggested that ßLG-EGCG conjugates were able to promote Th1/Th2 immune balance. These findings further our understanding of the relationship between the degree of polyphenol conjugation and the allergenicity of food allergens.


Asunto(s)
Alérgenos , Catequina , Inmunoglobulina E , Lactoglobulinas , Lactoglobulinas/química , Lactoglobulinas/inmunología , Catequina/análogos & derivados , Catequina/química , Catequina/inmunología , Animales , Alérgenos/inmunología , Alérgenos/química , Bovinos , Inmunoglobulina E/inmunología , Humanos , Ratones , Hipersensibilidad a la Leche/inmunología , Hipersensibilidad a la Leche/prevención & control , Ratones Endogámicos BALB C , Femenino , Interferón gamma/inmunología , Interferón gamma/metabolismo , Quimasas/química , Quimasas/inmunología , Quimasas/metabolismo , Células Th2/inmunología , Células Th2/efectos de los fármacos , Interleucina-5/inmunología , Interleucina-10/inmunología , Interleucina-10/metabolismo , Interleucina-4/inmunología , Interleucina-4/metabolismo , Mastocitos/inmunología , Mastocitos/efectos de los fármacos
2.
Food Chem ; 460(Pt 2): 140605, 2024 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-39068806

RESUMEN

We prepared the ß-lactoglobulin (BLG)-ferulic acid (FA)-glucose (Glu) conjugates by alkaline method and Maillard reaction to assess the allergenicity. FA and Glu can form a ternary covalent conjugate with BLG, as evidenced by the shortening of SEC retention time, upward migration of SDS-PAGE protein bands, considerable decrease in free amino and sulfhydryl content, and changes in multistructure. BLG-Glu-FA conjugates weakly bound to immunoglobulin E in allergic sera was weak, reduced interleukin 4 and tumor necrosis factor α levels in RBL-2H3 cells and histamin and interleukin 6 secretion levels in KU812 cells, and inhibited the nuclear factor-κB signaling pathway. In vivo experiments showed that the conjugates regulated T-cell homeostasis in mouse splenic and mesenteric lymphocytes and attenuated splenic and duodenal immune injury. Therefore, the conjugates of BLG with FA combined with Glu altered the epitope structure and exhibited low allergenicity.


Asunto(s)
Alérgenos , Ácidos Cumáricos , Glucosa , Lactoglobulinas , Animales , Lactoglobulinas/química , Lactoglobulinas/inmunología , Ratones , Ácidos Cumáricos/química , Humanos , Alérgenos/inmunología , Alérgenos/química , Glucosa/química , Inmunoglobulina E/inmunología , Ratones Endogámicos BALB C , Femenino , Bovinos
3.
J Agric Food Chem ; 72(27): 15198-15212, 2024 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-38941263

RESUMEN

Numerous studies have highlighted the potential of Lactic acid bacteria (LAB) fermentation of whey proteins for alleviating allergies. Nonetheless, the impact of LAB-derived metabolites on whey proteins antigenicity during fermentation remains uncertain. Our objective was to elucidate the impact of small molecular metabolites on the antigenicity of α-lactalbumin (α-LA) and ß-lactoglobulin (ß-LG). Through metabolomic analysis, we picked 13 bioactive small molecule metabolites from Lactobacillus delbrueckii subsp. bulgaricus DLPU F-36 for coincubation with α-LA and ß-LG, respectively. The outcomes revealed that valine, arginine, benzoic acid, 2-keto butyric acid, and glutaric acid significantly diminished the sensitization potential of α-LA and ß-LG, respectively. Moreover, chromatographic analyses unveiled the varying influence of small molecular metabolites on the structure of α-LA and ß-LG, respectively. Notably, molecular docking underscored that the primary active sites of α-LA and ß-LG involved in protein binding to IgE antibodies aligned with the interaction sites of small molecular metabolites. In essence, LAB-produced metabolites wield a substantial influence on the antigenic properties of whey proteins.


Asunto(s)
Lactobacillus delbrueckii , Simulación del Acoplamiento Molecular , Proteína de Suero de Leche , Lactobacillus delbrueckii/metabolismo , Lactobacillus delbrueckii/química , Lactobacillus delbrueckii/inmunología , Proteína de Suero de Leche/química , Proteína de Suero de Leche/metabolismo , Fermentación , Lactoglobulinas/química , Lactoglobulinas/inmunología , Lactoglobulinas/metabolismo , Lactalbúmina/química , Lactalbúmina/inmunología , Lactalbúmina/metabolismo , Animales , Bovinos , Antígenos/inmunología , Antígenos/química
4.
J Agric Food Chem ; 72(20): 11746-11758, 2024 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-38718253

RESUMEN

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.


Asunto(s)
Alérgenos , Ácidos Cumáricos , Microbioma Gastrointestinal , Glucosa , Lactoglobulinas , Ácidos Cumáricos/metabolismo , Ácidos Cumáricos/química , Animales , Lactoglobulinas/inmunología , Lactoglobulinas/química , Lactoglobulinas/metabolismo , Ratones , Humanos , Alérgenos/inmunología , Alérgenos/química , Alérgenos/metabolismo , Glucosa/metabolismo , Femenino , Bacterias/inmunología , Bacterias/metabolismo , Bacterias/clasificación , Bacterias/genética , Ratones Endogámicos BALB C , Inmunoglobulina E/inmunología , Inmunoglobulina E/sangre , Ácidos Grasos Volátiles/metabolismo , Bovinos , Inmunoglobulina G/inmunología , Inmunoglobulina G/sangre , Hipersensibilidad a la Leche/inmunología
5.
J Food Sci ; 89(7): 4505-4521, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38778560

RESUMEN

Cow milk allergy is one of the common food allergies. Our previous study showed that the allergenicity of fermented milk is lower than that of unfermented skimmed milk in vitro, and the antigenicity of ß-lactoglobulin and α-lactalbumin in fermented milk was decreased by 67.54% and 80.49%, respectively. To confirm its effects in vivo, allergic BALB/C mice model was used to further study the allergenicity of fermented milk. It was found that compared with the skim milk (SM) group, the intragastrically sensitization with fermented milk had no obvious allergic symptoms and the fingers were more stable: lower levels of IgE, IgG, and IgA in serum, lower levels of plasma histamine and mast cell protein-1, and immune balance of Th1/Th2 and Treg/Th17. At the same time, intragastrically sensitization with fermented milk increased the α diversity of intestinal microbiota and changed the microbiota abundance: the relative abundance of norank-f-Muribaculaceae and Staphylococcus significantly decreased, and the abundance of Lachnospiraceae NK4A136 group, Bacteroides, and Turicibacter increased. In addition, fermented milk can also increase the level of short-chain fatty acids in the intestines of mice. It turns out that fermented milk is much less allergenicity than SM. PRACTICAL APPLICATION: Fermentation provides a theoretical foundation for reducing the allergenicity of milk and dairy products, thereby facilitating the production of low-allergenic dairy products suitable for individuals with milk allergies.


Asunto(s)
Fermentación , Microbioma Gastrointestinal , Inmunoglobulina E , Lactobacillales , Ratones Endogámicos BALB C , Hipersensibilidad a la Leche , Leche , Animales , Hipersensibilidad a la Leche/inmunología , Ratones , Inmunoglobulina E/inmunología , Inmunoglobulina E/sangre , Leche/inmunología , Femenino , Lactobacillales/inmunología , Bovinos , Productos Lácteos Cultivados/microbiología , Lactoglobulinas/inmunología , Inmunoglobulina A , Lactalbúmina/inmunología , Inmunoglobulina G/sangre , Ácidos Grasos Volátiles/metabolismo , Histamina/metabolismo
6.
Int J Biol Macromol ; 268(Pt 1): 131773, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38657930

RESUMEN

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.


Asunto(s)
Catequina , Lactoglobulinas , Lactoglobulinas/química , Lactoglobulinas/inmunología , Catequina/análogos & derivados , Catequina/química , Catequina/farmacología , Concentración de Iones de Hidrógeno , Simulación de Dinámica Molecular , Estructura Secundaria de Proteína , Dicroismo Circular , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Simulación del Acoplamiento Molecular , Antígenos/inmunología , Antígenos/química
7.
Food Funct ; 12(22): 11343-11350, 2021 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-34668899

RESUMEN

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.


Asunto(s)
Catequina/análogos & derivados , Desensibilización Inmunológica , Lactoglobulinas , Alérgenos/inmunología , Animales , Catequina/química , Catequina/inmunología , Catequina/farmacología , Femenino , Microbioma Gastrointestinal/efectos de los fármacos , Microbioma Gastrointestinal/inmunología , Tolerancia Inmunológica/inmunología , Inmunoglobulina E/inmunología , Lactoglobulinas/química , Lactoglobulinas/inmunología , Lactoglobulinas/farmacología , Ratones , Ratones Endogámicos BALB C
8.
Nutrients ; 13(9)2021 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-34578889

RESUMEN

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.


Asunto(s)
Alérgenos , Fórmulas Infantiles/análisis , Lactoglobulinas , Hipersensibilidad a la Leche , Péptidos , Proteína de Suero de Leche , Alérgenos/inmunología , Animales , Cromatografía , Dermatitis Atópica , Industria de Alimentos , Alimentos Formulados , Humanos , Hidrólisis , Inmunoglobulina E , Lactante , Lactoglobulinas/análisis , Lactoglobulinas/inmunología , Hipersensibilidad a la Leche/prevención & control , Proteínas de la Leche , Peso Molecular , Péptidos/análisis , Péptidos/inmunología , Hidrolisados de Proteína/análisis , Hidrolisados de Proteína/inmunología , Ratas Sprague-Dawley , Suero Lácteo , Proteína de Suero de Leche/análisis , Proteína de Suero de Leche/inmunología
9.
Food Funct ; 12(20): 10107-10120, 2021 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-34522929

RESUMEN

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.


Asunto(s)
Alérgenos/inmunología , Antocianinas/química , Caseínas/química , Lactoglobulinas/química , Animales , Antocianinas/inmunología , Antocianinas/metabolismo , Caseínas/inmunología , Caseínas/metabolismo , Digestión , Dispersión Dinámica de Luz/métodos , Humanos , Inmunoglobulina E/química , Inmunoglobulina E/inmunología , Lactoglobulinas/inmunología , Lactoglobulinas/metabolismo , Proteínas de la Leche/química , Proteínas de la Leche/inmunología , Proteínas de la Leche/metabolismo , Tamaño de la Partícula , Unión Proteica , Conformación Proteica , Espectrometría de Fluorescencia/métodos
10.
Front Immunol ; 12: 611474, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33746954

RESUMEN

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.


Asunto(s)
Alérgenos/inmunología , Protección Cruzada/inmunología , Lactoglobulinas/inmunología , Polen/inmunología , Rinitis Alérgica Estacional/inmunología , Rinitis Alérgica Estacional/prevención & control , Administración Intranasal , Animales , Especificidad de Anticuerpos , Presentación de Antígeno/inmunología , Bovinos , Citocinas/metabolismo , Femenino , Inmunización Pasiva , Inmunoglobulina E/inmunología , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Lactoglobulinas/administración & dosificación , Ratones , Polen/efectos adversos , Células Th2/inmunología , Células Th2/metabolismo
11.
Food Chem ; 350: 129139, 2021 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-33588281

RESUMEN

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.


Asunto(s)
Lactoglobulinas/inmunología , Lactoglobulinas/metabolismo , Simulación de Dinámica Molecular , Péptido Hidrolasas/metabolismo , Animales , Dominio Catalítico , Hidrólisis , Inmunoglobulina G/inmunología , Lactoglobulinas/química , Simulación del Acoplamiento Molecular , Proteína de Suero de Leche/metabolismo
12.
Mol Nutr Food Res ; 65(8): e2000834, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33559978

RESUMEN

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.


Asunto(s)
Células Presentadoras de Antígenos/metabolismo , Lactoglobulinas/inmunología , Lactoglobulinas/metabolismo , Animales , Antígenos de Neoplasias/metabolismo , Proteínas Sanguíneas/metabolismo , Antígenos CD36/metabolismo , Digestión , Endocitosis/fisiología , Manipulación de Alimentos , Galectinas/metabolismo , Humanos , Lactante , Lactoglobulinas/química , Lactoglobulinas/farmacocinética , Macrófagos/metabolismo , Leche/química , Hipersensibilidad a la Leche/inmunología , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Receptores Depuradores de Clase A/metabolismo
13.
Food Chem ; 343: 128402, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-33406572

RESUMEN

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.


Asunto(s)
Lactoglobulinas/química , Polietilenglicoles/química , Animales , Antígenos/química , Antígenos/inmunología , Bovinos , Ensayo de Inmunoadsorción Enzimática , Lactoglobulinas/inmunología , Peso Molecular , Estructura Cuaternaria de Proteína , Estructura Secundaria de Proteína , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción
14.
Nutrients ; 13(2)2021 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-33503831

RESUMEN

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.


Asunto(s)
Caseínas/inmunología , Lactoglobulinas/inmunología , Hipersensibilidad a la Leche/inmunología , Linfocitos T/inmunología , Animales , Modelos Animales de Enfermedad , Femenino , Ratones , Ratones Endogámicos BALB C
15.
Int Immunol ; 33(3): 183-189, 2021 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-33027513

RESUMEN

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.


Asunto(s)
Anafilaxia/inmunología , Factor Estimulante de Colonias de Granulocitos y Macrófagos/genética , Inmunoglobulina E/inmunología , Lactoglobulinas/inmunología , Hipersensibilidad a la Leche/inmunología , Anafilaxia/mortalidad , Animales , Basófilos/inmunología , Bovinos , Modelos Animales de Enfermedad , Epinefrina/uso terapéutico , Factor Estimulante de Colonias de Granulocitos y Macrófagos/metabolismo , Trasplante de Células Madre Hematopoyéticas , Células Madre Hematopoyéticas , Histamina/sangre , Humanos , Interleucina-3/genética , Interleucina-3/metabolismo , Mastocitos/inmunología , Ratones , Ratones Endogámicos NOD , Ratones Transgénicos
16.
Methods Mol Biol ; 2223: 67-78, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33226587

RESUMEN

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.


Asunto(s)
Anafilaxia/inmunología , Modelos Animales de Enfermedad , Lactoglobulinas/inmunología , Hipersensibilidad a la Leche/inmunología , Leche/inmunología , Adyuvantes Inmunológicos/administración & dosificación , Administración Oral , Alérgenos/administración & dosificación , Alérgenos/inmunología , Anafilaxia/sangre , Anafilaxia/patología , Animales , Bovinos , Toxina del Cólera/administración & dosificación , Femenino , Humanos , Inmunoglobulina E/sangre , Inmunoglobulina E/inmunología , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Lactoglobulinas/administración & dosificación , Masculino , Ratones , Ratones Endogámicos C57BL , Leche/efectos adversos , Hipersensibilidad a la Leche/sangre , Hipersensibilidad a la Leche/patología
17.
Methods Mol Biol ; 2223: 159-167, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33226594

RESUMEN

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.


Asunto(s)
Proteínas Bacterianas/metabolismo , Ensayo de Inmunoadsorción Enzimática/métodos , Inmunoglobulina E/sangre , Inmunoglobulina G/aislamiento & purificación , Separación Inmunomagnética , Hipersensibilidad a la Leche/sangre , Animales , Biotina/química , Peroxidasa de Rábano Silvestre/química , Inmunoglobulina G/sangre , Lactoglobulinas/administración & dosificación , Lactoglobulinas/inmunología , Masculino , Ratones , Ratones Endogámicos C57BL , Hipersensibilidad a la Leche/etiología , Hipersensibilidad a la Leche/inmunología , Unión Proteica , Estreptavidina/química
18.
Food Chem ; 339: 128106, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33152886

RESUMEN

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.


Asunto(s)
Flavonoides/farmacología , Lactoglobulinas/química , Lactoglobulinas/inmunología , Alérgenos/química , Alérgenos/inmunología , Alérgenos/metabolismo , Dicroismo Circular , Epítopos/metabolismo , Flavonoides/química , Flavonoides/metabolismo , Lactoglobulinas/metabolismo , Simulación del Acoplamiento Molecular , Conformación Proteica , Espectrometría de Fluorescencia , Espectroscopía Infrarroja por Transformada de Fourier , Análisis Espectral
20.
Allergol Immunopathol (Madr) ; 48(6): 666-674, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33131977

RESUMEN

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.


Asunto(s)
Colon/patología , Redes Reguladoras de Genes/inmunología , Lactoglobulinas/efectos adversos , MicroARNs/metabolismo , Hipersensibilidad a la Leche/genética , Animales , Colon/inmunología , Citocinas/genética , Modelos Animales de Enfermedad , Femenino , Perfilación de la Expresión Génica , Humanos , Mucosa Intestinal/inmunología , Mucosa Intestinal/patología , Lactoglobulinas/inmunología , Ratones , Hipersensibilidad a la Leche/inmunología
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