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1.
Nutrients ; 16(8)2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38674882

RESUMEN

BACKGROUND: Tropomyosins (TM) from vertebrates are generally non-allergenic, while invertebrate homologs are potent pan-allergens. This study aims to compare the risk of sensitization between chicken TM and shrimp TM through affecting the intestinal epithelial barrier integrity and type 2 mucosal immune activation. METHODS: Epithelial activation and/or barrier effects upon exposure to 2-50 µg/mL chicken TM, shrimp TM or ovalbumin (OVA) as a control allergen, were studied using Caco-2, HT-29MTX, or HT-29 intestinal epithelial cells. Monocyte-derived dendritic cells (moDC), cocultured with HT-29 cells or moDC alone, were exposed to 50 µg/mL chicken TM or shrimp TM. Primed moDC were cocultured with naïve Th cells. Intestinal barrier integrity (TEER), gene expression, cytokine secretion and immune cell phenotypes were determined in these human in vitro models. RESULTS: Shrimp TM, but not chicken TM or OVA exposure, profoundly disrupted intestinal barrier integrity and increased alarmin genes expression in Caco-2 cells. Proinflammatory cytokine secretion in HT-29 cells was only enhanced upon shrimp TM or OVA, but not chicken TM, exposure. Shrimp TM enhanced the maturation of moDC and chemokine secretion in the presence or absence of HT-29 cells, while only in the absence of epithelial cells chicken TM activated moDC. Direct exposure of moDC to shrimp TM increased IL13 and TNFα secretion by Th cells cocultured with these primed moDC, while shrimp TM exposure via HT-29 cells cocultured with moDC sequentially increased IL13 expression and IL4 secretion in Th cells. CONCLUSIONS: Shrimp TM, but not chicken TM, disrupted the epithelial barrier while triggering type 2 mucosal immune activation, both of which are key events in allergic sensitization.


Asunto(s)
Alérgenos , Pollos , Técnicas de Cocultivo , Células Dendríticas , Mucosa Intestinal , Células Th2 , Tropomiosina , Animales , Humanos , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Células Dendríticas/efectos de los fármacos , Células CACO-2 , Tropomiosina/inmunología , Alérgenos/inmunología , Mucosa Intestinal/inmunología , Mucosa Intestinal/metabolismo , Células HT29 , Células Th2/inmunología , Citocinas/metabolismo , Penaeidae/inmunología , Células Epiteliales/metabolismo , Células Epiteliales/efectos de los fármacos , Células Epiteliales/inmunología , Ovalbúmina
2.
Allergy ; 2024 Feb 29.
Artículo en Inglés | MEDLINE | ID: mdl-38425053

RESUMEN

Mass spectrometry (MS) has advanced greatly and many of its applications are ready for utilization within regulatory procedures and could significantly contribute to overcome challenges in standardization of allergen products. It seems sensible to discuss MS within the regulatory framework, before addressing technical questions. While the application to purified proteins is well established from product development to manufacturer's release analytics, its application to complex products such as allergen products is still under development. It needs to be determined where it can complement or replace established methods or where MS offers limited improvement. Despite its technical appeal and versatility, currently MS is mentioned in regulatory guidelines only as one possible measurement method. For example, no specific MS method is given in the European Pharmacopoeia. We discuss applications of MS within the EU regulatory framework. This includes their advantages and disadvantages and their positioning between research, characterization, manufacturer's release analytics and official batch testing. We discuss the qualitative detection of single and multiple allergens as proof of identity, qualitative to semi-quantitative protein profiles for batch to batch consistency testing, and quantification of allergens to state mass units of allergens. MS may also facilitate standardization of allergen products, reference products and reference standards.

3.
Pediatr Allergy Immunol ; 34 Suppl 28: e13854, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-37186333

RESUMEN

Since the discovery of immunoglobulin E (IgE) as a mediator of allergic diseases in 1967, our knowledge about the immunological mechanisms of IgE-mediated allergies has remarkably increased. In addition to understanding the immune response and clinical symptoms, allergy diagnosis and management depend strongly on the precise identification of the elicitors of the IgE-mediated allergic reaction. In the past four decades, innovations in bioscience and technology have facilitated the identification and production of well-defined, highly pure molecules for component-resolved diagnosis (CRD), allowing a personalized diagnosis and management of the allergic disease for individual patients. The first edition of the "EAACI Molecular Allergology User's Guide" (MAUG) in 2016 rapidly became a key reference for clinicians, scientists, and interested readers with a background in allergology, immunology, biology, and medicine. Nevertheless, the field of molecular allergology is moving fast, and after 6 years, a new EAACI Taskforce was established to provide an updated document. The Molecular Allergology User's Guide 2.0 summarizes state-of-the-art information on allergen molecules, their clinical relevance, and their application in diagnostic algorithms for clinical practice. It is designed for both, clinicians and scientists, guiding health care professionals through the overwhelming list of different allergen molecules available for testing. Further, it provides diagnostic algorithms on the clinical relevance of allergenic molecules and gives an overview of their biology, the basic mechanisms of test formats, and the application of tests to measure allergen exposure.


Asunto(s)
Hipersensibilidad , Humanos , Hipersensibilidad/diagnóstico , Hipersensibilidad/terapia , Alérgenos , Inmunoglobulina E
4.
Clin Rev Allergy Immunol ; 62(1): 37-63, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32876924

RESUMEN

This review searched for published evidence that could explain how different physicochemical properties impact on the allergenicity of food proteins and if their effects would follow specific patterns among distinct protein families. Owing to the amount and complexity of the collected information, this literature overview was divided in two articles, the current one dedicated to protein families of plant allergens and a second one focused on animal allergens. Our extensive analysis of the available literature revealed that physicochemical characteristics had consistent effects on protein allergenicity for allergens belonging to the same protein family. For example, protein aggregation contributes to increased allergenicity of 2S albumins, while for legumins and cereal prolamins, the same phenomenon leads to a reduction. Molecular stability, related to structural resistance to heat and proteolysis, was identified as the most common feature promoting plant protein allergenicity, although it fails to explain the potency of some unstable allergens (e.g. pollen-related food allergens). Furthermore, data on physicochemical characteristics translating into clinical effects are limited, mainly because most studies are focused on in vitro IgE binding. Clinical data assessing how these parameters affect the development and clinical manifestation of allergies is minimal, with only few reports evaluating the sensitising capacity of modified proteins (addressing different physicochemical properties) in murine allergy models. In vivo testing of modified pure proteins by SPT or DBPCFC is scarce. At this stage, a systematic approach to link the physicochemical properties with clinical plant allergenicity in real-life scenarios is still missing.


Asunto(s)
Alérgenos , Hipersensibilidad a los Alimentos , Alérgenos/química , Animales , Hipersensibilidad a los Alimentos/etiología , Humanos , Ratones , Proteínas de Plantas , Polen
5.
Allergy ; 77(2): 633-642, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34241919

RESUMEN

BACKGROUND: The aim of the BSP090 project is the establishment of European Pharmacopoeia Chemical Reference Substances (CRSs) in combination with corresponding standard ELISA methods for quantification of major allergens in allergen products. Here, we present data of a Phl p 5-specific sandwich ELISA that proved suitable for the quantification of Phl p 5, one of the major Timothy grass (Phleum pratense) pollen allergens. METHODS: A Phl p 5-specific ELISA system was assessed with respect to accuracy, precision, inter-assay (within laboratory) and inter-laboratory variations, in a ring trial including 14 laboratories in Europe and the USA. Model samples containing recombinant Phl p 5a CRS as well as native grass pollen extracts were analysed. Each participant was instructed to perform at least one preliminary assay to familiarise with the protocol, followed by three independent assays. RESULTS: The candidate standard ELISA proved suitable to quantify recombinant and native Phl p 5 with satisfactory precision (93% of results within ±30% acceptance range). Inter-assay variation (max. GCV 24%) and especially inter-laboratory variation (max. GCV 13%) showed conclusive results. When assessing accuracy by means of recovery of recombinant spikes from a grass pollen extract matrix, similarly satisfactory spike recovery results were observed for the two spikes with higher concentrations (all within ±30% acceptance range), whereas recovery of the lowest concentration spike was slightly poorer with mean results of six laboratories exceeding acceptance range. CONCLUSIONS: Based on the collaborative study results, the assessed Phl p 5-specific immunoassay is appropriate to be proposed as European Pharmacopoeia standard method.


Asunto(s)
Alérgenos , Polen , Alérgenos/química , Ensayo de Inmunoadsorción Enzimática , Humanos , Phleum/química , Proteínas de Plantas/química , Poaceae , Estándares de Referencia
6.
Clin Rev Allergy Immunol ; 62(1): 1-36, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33411319

RESUMEN

Key determinants for the development of an allergic response to an otherwise 'harmless' food protein involve different factors like the predisposition of the individual, the timing, the dose, the route of exposure, the intrinsic properties of the allergen, the food matrix (e.g. lipids) and the allergen modification by food processing. Various physicochemical parameters can have an impact on the allergenicity of animal proteins. Following our previous review on how physicochemical parameters shape plant protein allergenicity, the same analysis was proceeded here for animal allergens. We found that each parameter can have variable effects, ranging on an axis from allergenicity enhancement to resolution, depending on its nature and the allergen. While glycosylation and phosphorylation are common, both are not universal traits of animal allergens. High molecular structures can favour allergenicity, but structural loss and uncovering hidden epitopes can also have a similar impact. We discovered that there are important knowledge gaps in regard to physicochemical parameters shaping protein allergenicity both from animal and plant origin, mainly because the comparability of the data is poor. Future biomolecular studies of exhaustive, standardised design together with strong validation part in the clinical context, together with data integration model systems will be needed to unravel causal relationships between physicochemical properties and the basis of protein allergenicity.


Asunto(s)
Alérgenos , Hipersensibilidad a los Alimentos , Alérgenos/química , Animales , Epítopos , Manipulación de Alimentos , Humanos , Proteínas
7.
Compr Rev Food Sci Food Saf ; 20(4): 3225-3266, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-34056857

RESUMEN

The last two decades saw a steady increase of high hydrostatic pressure (HHP) used for treatment of foods. Although the science of biomaterials exposed to high pressure started more than a century ago, there still seem to be a number of unanswered questions regarding safety of foods processed using HHP. This review gives an overview on historical development and fundamental aspects of HHP, as well as on potential risks associated with HHP food applications based on available literature. Beside the combination of pressure and temperature, as major factors impacting inactivation of vegetative bacterial cells, bacterial endospores, viruses, and parasites, factors, such as food matrix, water content, presence of dissolved substances, and pH value, also have significant influence on their inactivation by pressure. As a result, pressure treatment of foods should be considered for specific food groups and in accordance with their specific chemical and physical properties. The pressure necessary for inactivation of viruses is in many instances slightly lower than that for vegetative bacterial cells; however, data for food relevant human virus types are missing due to the lack of methods for determining their infectivity. Parasites can be inactivated by comparatively lower pressure than vegetative bacterial cells. The degrees to which chemical reactions progress under pressure treatments are different to those of conventional thermal processes, for example, HHP leads to lower amounts of acrylamide and furan. Additionally, the formation of new unknown or unexpected substances has not yet been observed. To date, no safety-relevant chemical changes have been described for foods treated by HHP. Based on existing sensitization to non-HHP-treated food, the allergenic potential of HHP-treated food is more likely to be equivalent to untreated food. Initial findings on changes in packaging materials under HHP have not yet been adequately supported by scientific data.


Asunto(s)
Manipulación de Alimentos , Inocuidad de los Alimentos , Bacterias , Humanos , Presión Hidrostática , Tecnología
8.
Foods ; 9(12)2020 Nov 26.
Artículo en Inglés | MEDLINE | ID: mdl-33255927

RESUMEN

Soybean (Glycine max) allergy can be life threatening. A lack of causative immunotherapy of soybean allergy makes soybean avoidance indispensable. Detection methods are essential to verify allergen labeling and unintentional allergen cross contact during food manufacture. Here, we aimed at evaluating our previously described primers for loop-mediated isothermal amplification (LAMP) of multicopy gene ORF160b, combined with a lateral flow dipstick (LFD)-like detection, for their performance of soybean detection in complex food matrices. The results were compared with those obtained using quantitative real-time Polymerase Chain Reaction (qPCR) as the current standard of DNA-based allergen detection, and antibody-based commercial lateral flow device (LFD) as the current reference of protein-based rapid allergen detection. LAMP-LFD allowed unequivocal and reproducible detection of 10 mg/kg soybean incurred in three representative matrices (boiled sausage, chocolate, instant tomato soup), while clear visibility of positive test lines of two commercial LFD tests was between 10 and 102 mg/kg and depending on the matrix. Sensitivity of soybean detection in incurred food matrices, commercial retail samples, as well as various processed soybean products was comparable between LAMP-LFD and qPCR. The DNA-based LAMP-LFD proved to be a simple and low-technology soybean detection tool, showing sensitivity and specificity that is comparable or superior to the investigated commercial protein-based LFD.

9.
Artículo en Alemán | MEDLINE | ID: mdl-33095280

RESUMEN

Currently, extract-based therapeutic allergens from natural allergen sources (e.g., house dust mites, tree and grass pollen) are used for allergen-specific immunotherapy (AIT), the only causative therapy that can exhibit positive disease-modifying effects by tolerance induction and prevention of disease progression. Due to variations in the natural composition of the starting materials and different manufacturing processes, there are variations in protein content, allergen composition, and allergenic activity of similar products, which poses specific challenges for their standardization. The identification of the nucleotide sequences of allergenic proteins led to the development of molecular AIT approaches. This allows for the application of exclusively relevant structures as chemically synthesized peptides, recombinant single allergens, or molecules with hypoallergenic properties that potentially allow for an up-dosing with higher allergen-doses without allergic side effects leading more quickly to effective cumulative doses. Further modifications of AIT preparations to improve allergenic and immunogenic properties may be achieved, e.g., by including the use of virus-like particles (VLPs). To date, the herein described therapeutic approaches have been tested in clinical trials only. This article provides an overview of published molecular approaches for allergy treatment used in clinical AIT studies. Their added value and challenges compared to established therapeutic allergens are discussed. The aim of these approaches is to develop highly effective and well-tolerated AIT preparations with improved patient acceptance and adherence.


Asunto(s)
Alérgenos , Hipersensibilidad , Desensibilización Inmunológica , Alemania , Humanos , Hipersensibilidad/terapia , Inmunoterapia , Péptidos
10.
Food Chem Toxicol ; 145: 111709, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32866515

RESUMEN

Food allergy affects up to 6% of Europeans. Allergen identification is important for the risk assessment and management of the inadvertent presence of allergens in foods. The VITAL® initiative for voluntary incidental trace allergen labeling suggests protein reference doses, based on clinical reactivity in food challenge studies, at or below which voluntary labelling is unnecessary. Here, we investigated if current analytical methodology could verify the published VITAL® 2.0 doses, that were available during this analysis, in serving sizes between 5 and 500 g. Available data on published and commercial ELISA, PCR and mass spectrometry methods, especially for the detection of peanuts, soy, hazelnut, wheat, cow's milk and hen's egg were reviewed in detail. Limit of detection, quantitative capability, matrix compatibility, and specificity were assessed. Implications by the recently published VITAL® 3.0 doses were also considered. We conclude that available analytical methods are capable of reasonably robust detection of peanut, soy, hazelnut and wheat allergens for levels at or below the VITAL® 2.0 and also 3.0 doses, with some methods even capable of achieving this in a large 500 g serving size. Cow's milk and hen's egg are more problematic, largely due to matrix/processing incompatibility. An unmet need remains for harmonized reporting units, available reference materials, and method ring-trials to enable validation and the provision of comparable measurement results.


Asunto(s)
Alérgenos/análisis , Análisis de los Alimentos/normas , Hipersensibilidad a los Alimentos/inmunología , Alimentos/efectos adversos , Animales , Ensayo de Inmunoadsorción Enzimática , Europa (Continente) , Análisis de los Alimentos/métodos , Humanos , Espectrometría de Masas
11.
Clin Transl Allergy ; 10: 13, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32477491

RESUMEN

The growing world population and increased pressure on agricultural resources are driving a shortage of dietary protein sources. As a result, industry is developing more sustainable novel food protein sources such as insects, algae and duckweed and using new processing techniques. Consumer exposure to these novel or processed proteins, could cause new food allergies, exacerbating a public health issue which is already directly affecting an estimated 20 million Europeans. Introduction of novel foods should not add to the burden of food allergy and this calls for a reliable, harmonised, evidence-based and validated allergenicity risk assessment strategy. The COST (Cooperation in Science and Technology) Action ImpARAS (Improved Allergenicity Risk Assessment Strategy), a four-year networking project, identified gaps in current allergy risk assessment, and proposed new ideas and plans for improving it. Here, we report on the lessons learned from the ImpARAS network and suggestions for future research. The safe introduction of novel and more sustainable food protein sources, while protecting humans from food allergy, calls for a multidisciplinary approach based on an improved understanding of what determines the relative allergenic potency of proteins, novel testing and assessment methodologies, harmonized decision-making criteria, and a clear ranking approach to express the allergenicity of novel product relative to that of existing known allergenic proteins: (from 'non'/to weakly and to strongly allergenic proteins).

13.
Foods ; 9(4)2020 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-32260089

RESUMEN

The soybean (Glycine max) has been recognized as a frequent elicitor of food allergy worldwide. A lack of causative immunotherapy of soybean allergy makes soybean avoidance essential. Therefore, sensitive and specific methods for soybean detection are needed to allow for soybean verification in foods. Loop-mediated isothermal amplification (LAMP) represents a rapid and simple DNA-based detection method principally suitable for field-like applications or on-site analytical screening for allergens during the manufacturing of foods. This work describes the systematic development and selection of suitable LAMP primers based on soybean multicopy genes. The chemistry applied allows for a versatile detection of amplified DNA, using either gel electrophoresis, fluorescence recording, or a simple Lateral Flow Dipstick (LFD). LAMP based on the ORF160b gene was highly specific for the soybean and may allow for a detection level equivalent to approximately 10 mg soy per kg food. Various soybean cultivars were detectable at a comparable level of sensitivity. LAMP combined with LFD-like detection facilitates a simple, highly specific and sensitive detection of the soybean without the need for expensive analytical equipment. In contrast to the majority of antibody-based methods for soybean detection, all identified primer sequences and optimized protocols are disclosed and broadly available to the community.

14.
Vaccine ; 38(15): 3105-3120, 2020 03 30.
Artículo en Inglés | MEDLINE | ID: mdl-32113806

RESUMEN

There are currently about 257 million people suffering from chronic HBV infection worldwide. In many cases, an insufficient Tcell response is causative for establishment of a chronic infection. To ensure a robust cellular immune response and induction of neutralizing antibodies a novel vaccine platform based on modified cell-permeable HBV capsids was utilized. Cell permeability was achieved by fusion of the membrane-permeable TLM-peptide to HBV core monomers, assembling the capsids. Insertion of a Strep-tagIII into the spike tip domain that protrudes from the capsid surface enables flexible loading with antigens that are fused to streptavidin. In this study, HBV surface antigen-derived PreS1PreS2 domain, fused to monomeric streptavidin, served as cargo antigen. Binding between antigen and capsids was characterized by surface plasmon resonance spectroscopy, electron microscopy and density gradient centrifugation. Confocal immunofluorescence microscopy and in vivo imaging of immunized mice demonstrated membrane permeability of cargo-loaded carriers and spread of antigen over the whole organism. Immunization experiments of mice revealed a robust induction of a specific cellular immune response, leading to destruction of HBV-positive cells and induction of HBV-specific neutralizing antibodies. Membrane permeability of these carriers allows needle-free application of antigen-loaded capsids as evidenced by induction of an HBV-specific CTL response and HBV-specific B cell response after oral or transdermal vaccination. These data indicate that cell-permeable antigen carriers, based on HBV capsids and loaded with HBV antigen, have the capacity to induce a cellular and a neutralizing humoral immune response. In addition, cell permeability of the vaccine platform enables antigen transfer across several cell layers, that could allow oral or transdermal immunization.


Asunto(s)
Antígenos del Núcleo de la Hepatitis B/inmunología , Antígenos de Superficie de la Hepatitis B/inmunología , Vacunas contra Hepatitis B/administración & dosificación , Hepatitis B Crónica , Inmunidad Celular , Animales , Antígenos del Núcleo de la Hepatitis B/administración & dosificación , Antígenos de Superficie de la Hepatitis B/administración & dosificación , Vacunas contra Hepatitis B/inmunología , Hepatitis B Crónica/prevención & control , Ratones , Vacunación
15.
Clin Exp Allergy ; 50(5): 625-635, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32078204

RESUMEN

BACKGROUND: Food allergy to pea (Pisum sativum) has been rarely studied in children at the clinical and molecular levels. OBJECTIVE: To elucidate the allergenic relevance and diagnostic value of pea 7S globulin Pis s 1, nsLTP, and 2S albumins PA1 and PA2 in children. METHODS: Children with pea-specific IgE ≥ 0.35 kUA /L and clinical evidence of pea allergy or tolerance were included in the study. IgE binding against pea total protein extract, recombinant (r) rPis s 1, rPA1, rPA2, and natural nsLTP was analysed using IgE immunoblot/inhibition. Mediator release potency was investigated in passively sensitized rat basophil leukaemia (RBL) 2H3-cells. IgE binding to synthetic overlapping peptides of Pis s 1 was detected on multipeptide microarrays. RESULTS: 19 pea-sensitized children were included, 14 with doctors' diagnosed allergy and 5 with tolerance to pea (median age 3.5 and 4.5 years, respectively). 11/14 (78%) pea-allergic and 1/5 (20%) tolerant children were sensitized to Pis s 1. Under the reducing conditions of immunoblot analysis, IgE binding to rPA1 was negligible, sensitization to rPA2 and nsLTP undetectable. Compared to pea total protein extract, rPis s 1 displayed on average 58% IgE binding capacity and a 20-fold higher mediator release potency. Selected Pis s 1-related peptides displayed IgE binding in pea-allergic but not in pea-tolerant children. CONCLUSIONS AND CLINICAL RELEVANCE: In this study group, Pis s 1 is a major immunodominant allergen in pea-allergic children. Evidence for sensitization to nsLTP and 2S albumins was low but requires further verification with regard to conformational epitopes. Recombinant Pis s 1 and related peptides which were exclusively recognized by pea-allergic children may improve in vitro diagnosis of pea allergy once verified in prospective studies with larger study groups.


Asunto(s)
Alérgenos , Hipersensibilidad a los Alimentos , Inmunoglobulina E/inmunología , Pisum sativum , Adolescente , Alérgenos/química , Alérgenos/genética , Alérgenos/inmunología , Animales , Sitios de Unión , Niño , Preescolar , Femenino , Hipersensibilidad a los Alimentos/diagnóstico , Hipersensibilidad a los Alimentos/inmunología , Humanos , Lactante , Masculino , Pisum sativum/genética , Pisum sativum/inmunología , Proteínas de Plantas/química , Proteínas de Plantas/genética , Proteínas de Plantas/inmunología , Ratas
16.
Clin Exp Allergy ; 50(1): 105-116, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31541579

RESUMEN

BACKGROUND: Novel foods may provide new protein sources for a growing world population but entail risks of unexpected food-allergic reactions. No guidance on allergenicity assessment of novel foods exists, while for genetically modified (GM) crops it includes comparison of sequence identity with known allergens, digestibility tests and IgE serum screening. OBJECTIVE: As a proof of concept, to evaluate non-/allergenic tropomyosins (TMs) regarding their potential as new calibrator proteins in functional biological in vitro assays for the semi-quantitative allergy risk assessment of novel TM-containing animal foods with mealworm TM as an example. METHODS: Purified TMs (shrimp, Penaeus monodon; chicken Gallus gallus; E coli overexpression) were compared by protein sequencing, circular dichroism analysis and in vitro digestion. IgE binding was quantified using shrimp-allergic patients' sera (ELISA). Biological activities were investigated (skin testing; titrated basophil activation tests, BAT), compared to titrated biological mediator release using humanized rat basophil leukaemia (RBL) cells. RESULTS: Shrimp and chicken TMs showed high sequence homology, both alpha-helical structures and thermal stability. Shrimp TM was stable during in vitro gastric digestion, chicken TM degraded quickly. Both TMs bound specific IgE from shrimp-allergic patients (significantly higher for shrimp TM), whereas skin reactivity was mostly positive with only shrimp TM. BAT and RBL cell assays were positive with shrimp and chicken TM, although at up to 100- to 1000-times lower allergen concentrations for shrimp than chicken TM. In RBL cell assays using both TM as calibrators, an activation of effector cells by mealworm TM similar to that by shrimp TM confirmed the already reported high allergenic potency of mealworm TM as a novel protein source. CONCLUSIONS & CLINICAL RELEVANCE: According to current GM crops' allergenicity assessment, non-allergenic chicken TM could falsely be considered an allergen on a weight-of-evidence approach. However, calibrating allergenic potency in functional BAT and RBL cell assays with clinically validated TMs allowed for semi-quantitative discrimination of novel food protein's allergenicity. With TM calibration as a proof of concept, similar systems of homologous protein might be developed to scale on an axis of allergenicity.


Asunto(s)
Alérgenos/inmunología , Proteínas Dietéticas Animales/inmunología , Pollos/inmunología , Penaeidae/inmunología , Hipersensibilidad a los Mariscos/inmunología , Tropomiosina/inmunología , Adolescente , Adulto , Animales , Niño , Insectos Comestibles , Escherichia coli , Femenino , Hipersensibilidad a los Alimentos , Abastecimiento de Alimentos , Alimentos Modificados Genéticamente , Humanos , Técnicas In Vitro , Masculino , Plantas Modificadas Genéticamente , Prueba de Estudio Conceptual , Homología Estructural de Proteína , Tenebrio/inmunología , Adulto Joven
17.
Viruses ; 11(8)2019 08 13.
Artículo en Inglés | MEDLINE | ID: mdl-31412626

RESUMEN

Infection with Zika virus (ZIKV) came first to public attention after it was found to be associated with congenital microcephaly during the outbreak in Brazil (2015-2016). Diagnosis of ZIKV suffers from extensive cross-reactivity with other Flaviviruses, which are circulating in many ZIKV epidemic areas. Due to the fatal outcome of ZIKV infection during pregnancy, detailed knowledge about neutralizing and non-neutralizing epitopes is crucial for the development of robust detection systems of protective antibodies. Therefore, additional information about ZIKV immunogenicity and antibody response is required. In this project, we report the production, purification and characterization of six different polyclonal antibodies against ZIKV envelope (E) protein. The produced antibodies bind to isolated ZIKV E protein as well as to the surface of ZIKV particles, interestingly without being potently neutralizing. Surface plasmon resonance measurement showed that these antibodies bind with high affinity to ZIKV E protein. Epitope mapping revealed that the epitopes are distributed among the three ZIKV E domains with seven binding sites. These identified binding sites overlap only partially with the previously described epitopes recognized by neutralizing antibodies, which is in accordance with their lack of potent neutralizing activity. Additionally, these antibodies showed neither cross-reactivity nor potent neutralizing activity against West Nile virus, a related flavivirus. The gained set of data helps to extend our understanding about the distribution of neutralizing and non-/weak-neutralizing epitopes in ZIKV E protein, and provides a rationale for ZIKV vaccine design and development of robust detection assays for neutralizing antibodies.


Asunto(s)
Anticuerpos Antivirales/inmunología , Anticuerpos Antivirales/aislamiento & purificación , Proteínas del Envoltorio Viral/inmunología , Infección por el Virus Zika/virología , Virus Zika/inmunología , Animales , Reacciones Cruzadas , Epítopos/genética , Epítopos/inmunología , Humanos , Inmunización , Pruebas de Neutralización , Conejos , Proteínas del Envoltorio Viral/genética , Virus Zika/genética , Infección por el Virus Zika/inmunología
18.
J Allergy Clin Immunol Pract ; 7(2): 479-491.e10, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30423449

RESUMEN

BACKGROUND: Only 2 small placebo-controlled trials on peanut oral immunotherapy (OIT) have been published. OBJECTIVE: We examined the efficacy, safety, immunologic parameters, quality of life (QOL), and burden of treatment (BOT) of low-dose peanut OIT in a multicenter, double-blind, randomized placebo-controlled trial. METHODS: A total of 62 children aged 3 to 17 years with IgE-mediated, challenge-proven peanut allergy were randomized (1:1) to receive peanut OIT with a maintenance dose of 125 to 250 mg peanut protein or placebo. The primary outcome was the proportion of children tolerating 300 mg or more peanut protein at oral food challenge (OFC) after 16 months of OIT. We measured the occurrence of adverse events (AEs), immunologic changes, and QOL before and after OIT and BOT during OIT. RESULTS: Twenty-three of 31 (74.2%) children of the active group tolerated at least 300 mg peanut protein at final OFC compared with 5 of 31 (16.1%) in the placebo group (P < .001). Thirteen of 31 (41.9%) children of the active versus 1 of 31 (3.2%) of the placebo group tolerated the highest dose of 4.5 g peanut protein at final OFC (P < .001). There was no significant difference between the groups in the occurrence of AE-related dropouts or in the number, severity, and treatment of objective AEs. In the peanut-OIT group, we noted a significant reduction in peanut-specific IL-4, IL-5, IL-10, and IL-2 production by PBMCs compared with the placebo group, as well as a significant increase in peanut-specific IgG4 levels and a significant improvement in QOL; 86% of children evaluated the BOT positively. DISCUSSION: Low-dose OIT is a promising, effective, and safe treatment option for peanut-allergic children, leading to improvement in QOL, a low BOT, and immunologic changes showing tolerance development.


Asunto(s)
Alérgenos/administración & dosificación , Desensibilización Inmunológica/métodos , Hipersensibilidad al Cacahuete/terapia , Calidad de Vida , Administración Oral , Adolescente , Niño , Preescolar , Desensibilización Inmunológica/efectos adversos , Método Doble Ciego , Femenino , Humanos , Masculino , Resultado del Tratamiento
19.
J Agric Food Chem ; 66(38): 9889-9894, 2018 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-30180550

RESUMEN

In food allergy, a common immunological disease with a potentially severe outcome, a causative cure is not available. Correct ingredient labeling and risk assessment of unlabeled allergen cross-contact is a prerequisite for effective allergen avoidance. Specific and sensitive analytical methods, which allow for unequivocal identification and accurate quantification of allergenic components, are important tools in allergen risk management. Both protein- and DNA-based methods are in place and reveal pros and cons depending upon the application and individual analytical question. This perspective highlights relevant molecular aspects and discusses, especially, opportunities for the application of DNA-based methods for the detection of allergenic foods.


Asunto(s)
Alérgenos/análisis , ADN/análisis , Proteínas/análisis , Alérgenos/genética , Animales , ADN/genética , Análisis de los Alimentos , Hipersensibilidad a los Alimentos/diagnóstico , Hipersensibilidad a los Alimentos/inmunología , Humanos , Proteínas/genética
20.
Mol Immunol ; 100: 3-13, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-29625844

RESUMEN

A systematic nomenclature for allergens originated in the early 1980s, when few protein allergens had been described. A group of scientists led by Dr. David G. Marsh developed a nomenclature based on the Linnaean taxonomy, and further established the World Health Organization/International Union of Immunological Societies (WHO/IUIS) Allergen Nomenclature Sub-Committee in 1986. Its stated aim was to standardize the names given to the antigens (allergens) that caused IgE-mediated allergies in humans. The Sub-Committee first published a revised list of allergen names in 1986, which continued to grow with rare publications until 1994. Between 1994 and 2007 the database was a text table online, then converted to a more readily updated website. The allergen list became the Allergen Nomenclature database (www.allergen.org), which currently includes approximately 880 proteins from a wide variety of sources. The Sub-Committee includes experts on clinical and molecular allergology. They review submissions of allergen candidates, using evidence-based criteria developed by the Sub-Committee. The review process assesses the biochemical analysis and the proof of allergenicity submitted, and aims to assign allergen names prior to publication. The Sub-Committee maintains and revises the database, and addresses continuous challenges as new "omics" technologies provide increasing data about potential new allergens. Most journals publishing information on new allergens require an official allergen name, which involves submission of confidential data to the WHO/IUIS Allergen Nomenclature Sub-Committee, sufficient to demonstrate binding of IgE from allergic subjects to the purified protein.


Asunto(s)
Alérgenos/inmunología , Animales , Bases de Datos Factuales , Humanos , Inmunoglobulina E/inmunología , Organización Mundial de la Salud
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