RESUMO
Tropomyosin (TM) is the main allergen in shrimp (Litopenaeus vannamei). In this study, the effects of allergenicity and structure of TM by glycosylation (GOS-TM), phosphate treatment (SP-TM), and glycosylation combined with phosphate treatment (GOS-SP-TM) were investigated. Compared to GOS-TM and SP-TM, the IgG/IgE binding capacity of GOS-SP-TM was significantly decreased with 63.9 ± 2.0 and 49.7 ± 2.7%, respectively. Meanwhile, the α-helix content reduced, surface hydrophobicity increased, and 10 specific amino acids (K30, K38, S39, K48, K66, K74, K128, K161, S210, and K251) were modified by glycosylation on six IgE linear epitopes of GOS-SP-TM. In the BALB/c mice allergy model, GOS-SP-TM could significantly reduce the levels of specific IgE, IgG1, and CD4+IL-4+, while the levels of IgG2a, CD4+CD25+Foxp3+, and CD4+IFN-γ+ were increased, which equilibrated Th1 and Th2 cells, thus alleviating allergic symptoms. These results indicated that glycosylation combined with phosphate treatment can provide a new insight into developing hypoallergenic shrimp food.
Assuntos
Alérgenos , Imunoglobulina E , Penaeidae , Fosfatos , Tropomiosina , Animais , Feminino , Humanos , Camundongos , Alérgenos/imunologia , Alérgenos/química , Proteínas de Artrópodes/imunologia , Proteínas de Artrópodes/química , Hipersensibilidade Alimentar/imunologia , Glicosilação , Imunoglobulina E/imunologia , Imunoglobulina G/imunologia , Imunoglobulina G/química , Camundongos Endogâmicos BALB C , Penaeidae/imunologia , Penaeidae/química , Fosfatos/química , Frutos do Mar/análise , Hipersensibilidade a Frutos do Mar/imunologia , Células Th2/imunologia , Células Th2/efeitos dos fármacos , Tropomiosina/imunologia , Tropomiosina/químicaRESUMO
Tropomyosin has been identified as the major cross-reactive shellfish allergen, but recent studies showed the presence of other clinically relevant allergens. This study aims at determining the allergic immune responses of mice sensitized with raw and boiled shrimp extracts in comparison to recombinant tropomyosin (rTM). Female Balb/c mice were intragastrically sensitized and challenged with raw, boiled shrimp or rTM. Systemic, cellular and humoral allergic responses were compared, while allergenicity of the extracts was also compared by skin prick test (SPT) and immunoblot on shrimp allergic subjects. We showed that rTM and shrimp extracts induced IgE- and Th2-mediated allergic responses in mice, distinguished by remarkable intestinal inflammation in small intestine across all regimens. Notably, boiled shrimp extract exhibited the highest sensitization rate (73.7% of mice developed positive TM-specific IgE response) when compared with raw extract (47.8%) and rTM (34.8%). Mice sensitized with boiled extract manifested the highest allergen-specific IgE and Th2 cytokine responses than the others. Immunoblot results indicated that tropomyosin remained the major allergen in extract-based sensitization and had stronger allergenicity in a heat-treated form comparing to untreated TM, which was in line with the SPT results that boiled extract induced larger wheal size in patients. Hemocyanin and glycogen phosphorylase were also identified as minor allergens associated with manifestation of shrimp allergy. This study shows that boiled extract enhanced sensitization and Th2 responses in agreement with the higher allergenicity of heat-treated TM. This study thus presents three shrimp allergy murine models suitable for mechanistic and intervention studies, and in vivo evidence implies higher effectiveness of boiled extract for the clinical diagnosis of shellfish allergy.
Assuntos
Alérgenos , Imunoglobulina E , Camundongos Endogâmicos BALB C , Hipersensibilidade a Frutos do Mar , Células Th2 , Tropomiosina , Adulto , Animais , Feminino , Humanos , Camundongos , Alérgenos/imunologia , Reações Cruzadas/imunologia , Citocinas/metabolismo , Modelos Animais de Doenças , Hipersensibilidade Alimentar/imunologia , Hipersensibilidade Alimentar/diagnóstico , Imunoglobulina E/imunologia , Imunoglobulina E/sangue , Penaeidae/imunologia , Frutos do Mar/efeitos adversos , Hipersensibilidade a Frutos do Mar/imunologia , Hipersensibilidade a Frutos do Mar/diagnóstico , Testes Cutâneos , Células Th2/imunologia , Tropomiosina/imunologiaRESUMO
Scy p 8 (triosephosphate isomerase) as a crab allergen in inducing distinct T-helper (Th) cell differentiation and a linear epitope associated with allergenicity remain elusive. In this study, mice sensitized with Scy p 8 exhibited significantly upregulated levels of IgE, IgG1, and IL-4 release, inducing a Th2 immune response. Moreover, the release of IFN-γ (Th1) and the levels of Treg cells were downregulated, while IL-17A (Th17) was upregulated, indicating that Scy p 8 disrupted the Th1/Th2 balance and Th17/Treg balance in mice. Furthermore, bioinformatics prediction and serum samples from crab-allergic patients and mice enabled the discovery of 8 linear epitopes of Scy p 8. Meanwhile, the analysis of peptide similarity and tertiary superposition revealed that 8 epitopes of Scy p 8 exhibited conservation across various species, potentially resulting in cross-reactivity. These findings possess the potential to enhance the comprehension of crab allergens, thereby establishing a foundation for investigating cross-reactivity.
Assuntos
Alérgenos , Braquiúros , Epitopos , Camundongos Endogâmicos BALB C , Animais , Braquiúros/imunologia , Braquiúros/genética , Braquiúros/química , Alérgenos/imunologia , Alérgenos/química , Alérgenos/genética , Humanos , Epitopos/imunologia , Epitopos/química , Camundongos , Feminino , Hipersensibilidade a Frutos do Mar/imunologia , Imunoglobulina E/imunologia , Proteínas de Artrópodes/imunologia , Proteínas de Artrópodes/genética , Proteínas de Artrópodes/química , Imunoglobulina G/imunologia , Imunoglobulina G/sangue , Células Th2/imunologia , Reações Cruzadas , Masculino , Interleucina-4/imunologia , Interleucina-4/genética , Adulto , Células Th1/imunologia , Interferon gama/imunologia , Interferon gama/genéticaRESUMO
Crustacean shellfish are major allergens in East Asia. In the present study, a major allergic protein in crustaceans, tropomyosin, was detected accurately using multiple reaction monitoring mode-based mass spectrometry, with shared signature peptides identified through proteomic analysis. The peptides were deliberately screened through thermal stability and enzymatic digestion efficiency to improve the suitability and accuracy of the developed method. Finally, the proposed method demonstrated a linear range of 0.15 to 30 mgTM/kgfood (R2 > 0.99), with a limit of detection of 0.15 mgTM/kg food and a limit of quantification of 0.5mgTM/kgfood and successfully applied to commercially processed foods, such as potato chips, biscuits, surimi, and hot pot seasonings, which evidenced the applicability of proteomics-based methodology for food allergen analysis.
Assuntos
Alérgenos , Crustáceos , Espectrometria de Massas , Peptídeos , Proteômica , Frutos do Mar , Tropomiosina , Tropomiosina/química , Tropomiosina/imunologia , Tropomiosina/análise , Animais , Proteômica/métodos , Alérgenos/química , Alérgenos/análise , Peptídeos/química , Frutos do Mar/análise , Espectrometria de Massas/métodos , Crustáceos/química , Proteínas de Artrópodes/química , Proteínas de Artrópodes/imunologia , Hipersensibilidade a Frutos do Mar/imunologia , Hipersensibilidade Alimentar/imunologia , Alimento ProcessadoRESUMO
Due to the widespread use of shellfish ingredients in food products, accurate food labelling is urgently needed for consumers with shellfish allergies. Most crustacean allergen detection systems target the immunorecognition of the allergenic protein tropomyosin. However, this mode of detection may be affected by an origin-dependent protein composition. This study determined if the geographic location of capture, or aquaculture, influenced the allergenic protein profiles of Black Tiger Shrimp (Penaeus monodon), one of the most farmed and consumed shrimp species worldwide. Protein composition was analysed in shrimp from nine different locations in the Asia-Pacific by SDS-PAGE, immunoblotting, and mass spectrometry. Ten of the twelve known shrimp allergens were detected, but with considerable differences between locations. Sarcoplasmic calcium-binding protein, myosin light chain, and tropomyosin were the most abundant allergens in all locations. Hemocyanin-specific antibodies could identify up to six different isoforms, depending on the location of origin. Similarly, tropomyosin abundance varied by up to 13 times between locations. These findings suggest that allergen abundance may be related to shrimp origin and, thus, shrimp origin might directly impact the readout of commercial crustacean allergen detection kits, most of which target tropomyosin, and this should be considered in food safety assessments.
Assuntos
Alérgenos , Inocuidade dos Alimentos , Penaeidae , Tropomiosina , Animais , Alérgenos/análise , Alérgenos/imunologia , Penaeidae/imunologia , Tropomiosina/imunologia , Hipersensibilidade a Frutos do Mar/imunologia , Frutos do Mar/análise , Frutos do Mar/efeitos adversosRESUMO
In recent years there has been an increase in the prevalence of allergic reactions to contact with/or consumption of crustaceans by immune responses mediated by IgE antibodies. Arginine kinase (AK) is considered one of the main allergens present in marine invertebrates. Currently, the allergenic potential of the brown crab (Callinectes bellicosus), which is a crustacean of great economic importance, has not been studied. Therefore, the aim of this work was to identify C. bellicosus AK as an allergen and to predict IgE-binding epitopes through immunobioinformatic analysis. AK was purified by precipitation with ammonium sulfate and ion- exchange chromatography. AK allergenicity was evaluated by IgE reactivity against sera from crustacean-allergic and non-allergic patients in both native and denaturing conditions. Additionally, a homology model was built based on the deduced amino acid sequence. A single band (~40 kDa) was found in SDS-PAGE, which was identified as an AK by mass spectrometry. AK showed immunoreactivity against crab-allergenic sera in both native and denaturing conditions with 70% and 80% positive reactions, respectively. Additionally, a 1073 bp ORF was obtained which codes for a deduced sequence of 357 amino acids corresponding to AK with > 90% identity with other AKs. Structural homology model of AK showed two main domains with conserved / folding of phospho-guanidine kinases. BediPred and Discotope were used for epitope prediction analysis, which suggests eight possible linear epitopes and seven conformational epitopes, respectively; and shows to be similar to other crustaceans AKs. C. bellicosus AK was identified as an allergenic protein by IgE reactivity and immunobioinformatic analysis indicates that both linear and conformational epitopes could be located in the surface of C. bellicosus AK structure.
Assuntos
Alérgenos/imunologia , Arginina Quinase/imunologia , Proteínas de Artrópodes/imunologia , Braquiúros/imunologia , Simulação por Computador , Epitopos/imunologia , Imunoglobulina E/imunologia , Hipersensibilidade a Frutos do Mar/imunologia , Proteínas de Frutos do Mar/imunologia , Animais , Braquiúros/enzimologia , HumanosRESUMO
Sarcoplasmic-calcium-binding protein (SCP) has been investigated as a novel allergen in Crassostrea angulata. Nevertheless, knowledge of its effector-cell-based allergic relevance and epitopes is limited. In this study, the heat-resistant allergen SCP was able to induce significant upregulation of CD63 and CD203c (p < 0.05), which showed obvious allergenicity in a basophil activation test. Furthermore, immunoinformatic tools, a one-bead-one-compound peptide library, and phage display technology were combined to analyze the allergenic epitopes of SCP. Five linear epitopes named L-SCP-1 (AA22-33), L-SCP-2 (AA64-75), L-SCP-3 (AA80-90), L-SCP-4 (AA107-116), and L-SCP-5 (AA144-159) were verified using serological tests. Additionally, two conformational epitopes (C-SCP-1 and C-SCP-2) were determined, and C-SCP-1 was located at one of the calcium-binding sites (AA106-117). Moreover, SCP showed weaker typical α-helical features and higher hydrophobicity after Ca2+ depletion, which reduced its IgE-binding capacity. Overall, these epitope data could enhance our understanding of oyster allergens, which could be used to develop hypoallergenic shellfish products.
Assuntos
Alérgenos/imunologia , Proteínas de Ligação ao Cálcio/imunologia , Crassostrea/imunologia , Epitopos/imunologia , Imunoglobulina E/imunologia , Hipersensibilidade a Frutos do Mar/imunologia , Proteínas de Frutos do Mar/imunologia , Adolescente , Adulto , Animais , Basófilos/imunologia , Cálcio/metabolismo , Proteínas de Ligação ao Cálcio/química , Criança , Pré-Escolar , Feminino , Temperatura Alta , Humanos , Masculino , Pessoa de Meia-Idade , Biblioteca de Peptídeos , Conformação Proteica , Estabilidade Proteica , Alinhamento de Sequência , Adulto JovemAssuntos
Proteínas Alimentares/imunologia , Enterocolite/imunologia , Hipersensibilidade Alimentar/imunologia , Animais , Grão Comestível/imunologia , Humanos , Lactente , Leite/imunologia , Hipersensibilidade a Leite/imunologia , Hipersensibilidade a Nozes e Amendoim/imunologia , Hipersensibilidade a Frutos do Mar/imunologia , Hipersensibilidade a Trigo/imunologiaRESUMO
Tectochrysin, a flavonoid compound, can be isolated from propolis, Alpinia oxyphylla Miq, and Lychnophora markgravii. This study evaluated the efficacy of tectochrysin in the treatment of shrimp tropomyosin (ST)-induced mouse asthma. Mice were sensitized with intraperitoneal (i.p.) injection of ST together with aluminum hydroxide as an adjuvant to establish a mouse model of asthma. Mice were i.p.-treated daily with tectochrysin. IgE levels in plasma, Th2 cytokines from both bronchoalveolar lavage (BAL) fluid and splenocytes, and CD200R on basophils in peripheral blood were measured. Histological analyses of lung tissues and accumulation of leukocytes in BAL fluid were performed. Lung eosinophil peroxidase, catalase and glutathione peroxidase activities were examined. ST was found to markedly increase eosinophilic inflammation and Th2 response in mice. Tectochrysin treatment reduced the level of IgE in plasma, the percentage of eosinophils in total white blood cells in peripheral blood, the total number of cells in BAL fluid, and eosinophil peroxidase activity in lung tissues. Tectochrysin attenuated ST-induced infiltration of eosinophils and epithelial mucus secretion in lung tissues and suppressed the overproduction of Th2 cytokines (IL-4 and IL-5) in BAL fluid. Tectochrysin also attenuated Th2 cytokine (IL-4 and IL-5) production from antigen-stimulated murine splenocytes in vitro, decreased the expression of CD200R on basophils in peripheral blood of asthmatic mice and inhibited IL-4 secretion from IgE-sensitized RBL-2H3 cells. In addition, tectochrysin enhanced catalase and glutathione peroxidase activities in lung tissues. Our findings demonstrate that TEC ameliorates allergic airway inflammation by suppressing Th2 response and oxidative stress.
Assuntos
Antiasmáticos/farmacologia , Anti-Inflamatórios não Esteroides/farmacologia , Asma/tratamento farmacológico , Flavonoides/farmacologia , Hipersensibilidade/tratamento farmacológico , Estresse Oxidativo/efeitos dos fármacos , Células Th2/imunologia , Alérgenos/imunologia , Animais , Antiasmáticos/administração & dosagem , Anti-Inflamatórios não Esteroides/administração & dosagem , Asma/induzido quimicamente , Asma/imunologia , Asma/patologia , Basófilos/metabolismo , Catalase/metabolismo , Modelos Animais de Doenças , Eosinófilos/metabolismo , Feminino , Flavonoides/administração & dosagem , Glutationa Peroxidase/metabolismo , Hipersensibilidade/imunologia , Imunoglobulina E/sangue , Injeções Intraperitoneais , Camundongos Endogâmicos C57BL , Muco/efeitos dos fármacos , Hipersensibilidade a Frutos do Mar/tratamento farmacológico , Hipersensibilidade a Frutos do Mar/imunologia , Tropomiosina/imunologiaRESUMO
Shrimp is a causative food that elicits food-dependent exercise-induced anaphylaxis (FDEIA). In this study, we sought to identify IgE-binding allergens in patients with shrimp-FDEIA. Sera were obtained from eight patients with shrimp-FDEIA and two healthy control subjects. Proteins were extracted from four shrimp species by homogenization in Tris buffer. Immunoblot analysis revealed that IgE from patient sera bound strongly to a 70-kDa and a 43-kDa protein in a preparation of Tris-soluble extracts from Litopenaeus vannamei. Mass spectrometry identified the 70-kDa and 43-kDa proteins as a P75 homologue and fructose 1,6-bisphosphate aldolase (FBPA), respectively. To confirm that the putative shrimp allergens were specifically recognized by serum IgE from shrimp-FDEIA patients, the two proteins were purified by ammonium sulfate precipitation followed by reversed-phase HPLC and/or anion-exchange hydrophobic interaction chromatography and then subjected to immunoblot analysis. Purified P75 homologue and FBPA were positively bound by serum IgE from one and three, respectively, of the eight patients with shrimp-FDEIA, but not by sera from control subjects. Thus, P75 homologue and FBPA are identified as IgE-binding allergens for shrimp-FDEIA. These findings could be useful for the development of diagnostic tools and desensitization therapy for shrimp-FDEIA patients.
Assuntos
Alérgenos , Anafilaxia/imunologia , Penaeidae , Alimentos Marinhos/efeitos adversos , Hipersensibilidade a Frutos do Mar/imunologia , Alérgenos/química , Alérgenos/imunologia , Alérgenos/isolamento & purificação , Animais , Humanos , Penaeidae/química , Penaeidae/imunologiaRESUMO
In order to reduce the immunoreactivity of sarcoplasmic calcium-binding protein (SCP), site-directed mutations were used to replace key amino acids in the conformational epitopes and calcium-binding sites. The mutant SCPs (mSCPs) were expressed in Escherichia coli, and their immunoreactivities were analyzed using iELISA and basophil activation assays. Furthermore, the structural changes of mSCPs were determined from the circular dichroism spectra. The iELISA results showed that mSCPs could effectively inhibit the binding of wild-type SCP (wtSCP) to sensitive serum, with inhibition rates that reached 90%. Moreover, mSCPs could downregulate the expression levels of CD63 and CD203c on the basophil surface. Compared with wtSCP, the peak values were significantly changed, and the calcium binding ability was impaired, which explained the decline in immunoreactivities of the mSCPs. All of the data confirmed that this approach was effective in reducing the immunoreactivity of SCP and could be applied to other shellfish allergens.
Assuntos
Proteínas de Artrópodes/genética , Proteínas de Artrópodes/imunologia , Braquiúros/imunologia , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/imunologia , Sequência de Aminoácidos , Animais , Proteínas de Artrópodes/química , Basófilos/imunologia , Braquiúros/química , Braquiúros/genética , Proteínas de Ligação ao Cálcio/química , Dicroísmo Circular , Epitopos/química , Epitopos/genética , Epitopos/imunologia , Humanos , Imunoglobulina E/imunologia , Mutagênese Sítio-Dirigida , Alinhamento de Sequência , Hipersensibilidade a Frutos do Mar/imunologiaRESUMO
BACKGROUND: Tropomyosin (TM) is the major allergen of crustaceans. The allergenicity of TM from Macrobrachium nipponense (MnTM) and the anaphylactic reaction in the digestive tract are still unclear. The aim of this study was to evaluate the allergenicity of MnTM and the anaphylactic reaction in the digestive tract. RESULTS: Serum IgE and IgG1 binding ability in the TM group were significantly higher than those in the PBS and CT groups (P < 0.01) and CP group (P < 0.05), while serum IgG and IgG2a binding ability showed no obvious difference between the four groups (P > 0.05). The levels of cytokines IL-4, IL-5 and IL-13 in TM and CP groups were significantly higher than those in PBS and CT groups. Histamine and ß-hexosaminidase in the TM and CP groups from basophil cell models were significantly higher than those in the PBS group. The highest mRNA expression of IL-4 and IL-13 was in the jejunum from TM-sensitized mice. Histopathological analysis showed that more immune cells infiltrated into the jejunum than the duodenum and ileum from the TM-sensitized mice. CONCLUSIONS: MnTM could promote an allergic response in mice and lead to degranulation in basophil cells. The jejunum was more easily affected by MnTM than duodenum and ileum, and the jejunum may be the major site of allergic response in the digestive tract. © 2020 Society of Chemical Industry.
Assuntos
Trato Gastrointestinal/imunologia , Palaemonidae/imunologia , Hipersensibilidade a Frutos do Mar/imunologia , Tropomiosina/imunologia , Alérgenos/genética , Alérgenos/imunologia , Animais , Citocinas/genética , Citocinas/imunologia , Feminino , Histamina/imunologia , Humanos , Imunoglobulina E/sangue , Imunoglobulina E/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Palaemonidae/genética , Hipersensibilidade a Frutos do Mar/genética , Células Th2 , Tropomiosina/genéticaRESUMO
Food allergy has been rising in prevalence over the last two decades, affecting more than 10% of the world population. Current management of IgE-mediated food allergy relies on avoidance and rescue medications; research into treatments that are safer and providing guaranteed and durable curative effects is, therefore, essential. T-cell epitope-based immunotherapy holds the potential for modulating food allergic responses without IgE cross-linking. In this chapter, we describe the methods in evaluating the therapeutic capacities of immunodominant T-cell epitopes in animal models of food allergy. Moreover, we explain in detail the methods to measure the allergen-specific antibody levels, prepare single-cell suspension from spleen, and prepare small intestine for immunohistochemical analysis of eosinophils and Foxp3+ cells.
Assuntos
Alérgenos/administração & dosagem , Dessensibilização Imunológica/métodos , Modelos Animais de Doenças , Hipersensibilidade a Ovo/terapia , Hipersensibilidade a Leite/terapia , Peptídeos/farmacologia , Hipersensibilidade a Frutos do Mar/terapia , Adjuvantes Imunológicos/administração & dosagem , Administração Oral , Hidróxido de Alumínio/administração & dosagem , Animais , Toxina da Cólera/administração & dosagem , Hipersensibilidade a Ovo/imunologia , Hipersensibilidade a Ovo/patologia , Ensaio de Imunoadsorção Enzimática/métodos , Eosinófilos/efeitos dos fármacos , Eosinófilos/imunologia , Epitopos de Linfócito T/química , Epitopos de Linfócito T/imunologia , Feminino , Humanos , Imunoglobulina E/genética , Imunoglobulina E/imunologia , Imuno-Histoquímica/métodos , Intestinos/efeitos dos fármacos , Intestinos/imunologia , Camundongos Endogâmicos BALB C , Hipersensibilidade a Leite/imunologia , Hipersensibilidade a Leite/patologia , Peptídeos/imunologia , Hipersensibilidade a Frutos do Mar/imunologia , Hipersensibilidade a Frutos do Mar/patologia , Baço/efeitos dos fármacos , Baço/imunologia , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologiaRESUMO
Little is known about genetic factors and mechanisms underlying shrimp allergy. Genome-wide association studies identified HLA class-II and IL13 genes as highly plausible candidates for shrimp allergy. The present study was designed to investigate potential associations of HLA-DQ rs9275596, IL13 rs20541, and IL13 rs1800925 polymorphisms with challenge-proven shrimp allergy using the data from 532 people of West Bengal, India; selected on basis of positive skin prick test, elevated specific IgE and medical history. Risk genotypes, i.e., HLA-DQ rs9275596 CC, IL13 rs20541 AA, and IL13 rs1800925 TT, were found to be significantly associated with challenge positive shrimp allergy (P = 0.04, 0.01, and 0.03, respectively). Distribution of genotypes for HLA-DQ and IL13 polymorphisms in allergic and control subjects showed significant difference between younger (20-40 years) and older (> 40 years) age group (P = 0.006). Risk genotypes significantly associated with elevated shrimp-specific IgE. IL13 TA haplotype significantly associated with shrimp allergy and elevated specific IgE (P = 0.02). Synergistic effect of IL13 TA haplotype-HLA-DQ rs9275596 CC genotype interaction significantly elevated specific IgE (P = 0.03). The present study suggests that HLA-DQ and IL13 polymorphisms pose major risk for shrimp allergic patients in West Bengal, India and thus could be helpful for early target-specific therapeutic intervention in near future.
Assuntos
Antígenos HLA-DQ/genética , Imunoglobulina E/sangue , Interleucina-13/genética , Penaeidae/imunologia , Polimorfismo de Nucleotídeo Único , Hipersensibilidade a Frutos do Mar/imunologia , Administração Oral , Adulto , Idoso , Animais , Estudos de Casos e Controles , Feminino , Seguimentos , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Genótipo , Haplótipos , Humanos , Imunoglobulina E/imunologia , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Hipersensibilidade a Frutos do Mar/epidemiologia , Hipersensibilidade a Frutos do Mar/genética , Adulto JovemRESUMO
Tropomyosin (TM) is the major shrimp allergen that could trigger anaphylactic reactions. Recently, recombinant TM (rTM) has been accepted widely in the field of allergen-specific immunotherapy, but the allergenicity of rTM has not been compared with natural TM (nTM) based on an in vitro digestion profile. In this work, IgG-/IgE binding, allergen peptides, and degranulation ability of the digested samples in simulated gastric fluid/simulated intestinal fluid/gastrointestinal models from nTM and rTM were evaluated by immunoassays, proteomics, and basophil degranulation assay. Results showed that pepsin-digested and trypsin-digested samples of rTM exhibited lower IgG-/IgE binding and degranulation than those of nTM. More peptides of the digested samples from rTM (57.8%) matched shrimp allergic epitopes than those from nTM (33.3%). However, the peptide SITDELDQTF (269-278) appeared most frequently. These findings would supply foundation data for epitope-based immunotherapy to shrimp allergic individuals.
Assuntos
Penaeidae/imunologia , Proteínas Recombinantes/imunologia , Hipersensibilidade a Frutos do Mar/imunologia , Tropomiosina/química , Tropomiosina/imunologia , Adolescente , Adulto , Alérgenos/química , Alérgenos/genética , Alérgenos/imunologia , Animais , Teste de Degranulação de Basófilos , Criança , Pré-Escolar , Feminino , Humanos , Imunoglobulina E/imunologia , Masculino , Espectrometria de Massas , Penaeidae/química , Penaeidae/genética , Proteômica , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Hipersensibilidade a Frutos do Mar/genética , Tropomiosina/genética , Adulto JovemRESUMO
Shrimps cause a significant part of crustacea-related allergies. It is used in processed foods, including fermented Korean foods, such as kimchi. Even low amounts of shrimp allergens can provoke reactions in consumers allergic to shrimp. Accurate food labeling is the most effective means of preventing the consumption of allergenic ingredients. To validate labeling compliance and minimize the risk of cross-contaminations, the effectiveness of methodologies used for the detection of allergens in foods should be compared. Here, seven commercial kits, based on quantitative real-time polymerase chain reaction (PCR) or enzyme-linked immunosorbent assay (ELISA), were assessed for their ability to detect the presence of shrimp allergens in food. Our results showed that SureFood real-time PCR kit and Ridascreen ELISA kit had the highest recovery, whereas five other kits underperformed in the determination of allergen content of kimchi and its ingredients. The variation in recovery among the kits depended on the limit of detection and reactivity to the shrimp allergens, tropomyosin, and sarcoplasmic calcium-binding protein. PRACTICAL APPLICATION: This research confirms the performance of commercial kits to detect the presence of shrimp allergens in kimchi, and demonstrates that the sensitivity of these kits depends on reactivity to the specific shrimp allergenic proteins. These results can be used to food allergy labeling and can be applied by the food industry to develop allergen test kits for fermented foods with improved performance.
Assuntos
Alérgenos/análise , Crustáceos/genética , DNA/genética , Ensaio de Imunoadsorção Enzimática/métodos , Alimentos Fermentados/análise , Reação em Cadeia da Polimerase/métodos , Hipersensibilidade a Frutos do Mar/prevenção & controle , Verduras/química , Alérgenos/genética , Alérgenos/imunologia , Animais , Crustáceos/química , Crustáceos/imunologia , Ensaio de Imunoadsorção Enzimática/economia , Rotulagem de Alimentos , Reação em Cadeia da Polimerase/economia , Hipersensibilidade a Frutos do Mar/imunologia , Verduras/imunologiaRESUMO
This work aimed to investigate the effect of enzymatic cross-linking on the allergenic potential of shrimp tropomyosin (TM), Met e 1. The cross-linked TM with laccase (CL), laccase/caffeic acid (CLC and CLC+), and transglutaminase (CTG and CTG+) formed macromolecules and altered the allergen conformation. The IgG/IgE-binding potentials of the cross-linked TM were reduced as confirmed by Western blotting and ELISA. Enzymatic cross-linking improved the gastrointestinal digestibility and induced a lower level of degranulation in RBL-2H3 and KU812 cells. Moreover, cross-linked TM decreased anaphylactic symptoms, as well as reduced the serum levels of IgG1, IgE, histamine, tryptase, and mMCP-1. In spleen cells, CLC+ and CTG+ downregulated the Th2-related cytokines and upregulated IFN-γ and IL-10. These findings revealed that CTG+ has shown more potential than CLC+ in mitigating the allergenicity of TM by influencing the conformational structure, enhancing the digestibility, decreasing the cellular degranulation process, and positively modulating the Th1/Th2 immunobalance.
Assuntos
Ácidos Cafeicos/química , Lacase/química , Penaeidae/imunologia , Transglutaminases/química , Tropomiosina/química , Tropomiosina/imunologia , Adulto , Alérgenos/química , Alérgenos/imunologia , Animais , Criança , Pré-Escolar , Feminino , Humanos , Imunoglobulina E/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Penaeidae/química , Hipersensibilidade a Frutos do Mar/imunologia , Hipersensibilidade a Frutos do Mar/prevenção & controle , Células Th1/imunologia , Células Th2/imunologiaRESUMO
Background: Moth is a common allergen in southern China. Shrimp sensitization might be related to the moth allergen. Objective: This study investigated sensitization to moth allergen in patients in southern China sensitized to shrimp and explored the effect of moth sensitization on different allergic diseases. Methods: Serum samples from 212 patients sensitized to shrimp were tested for specific immunoglobulin E (sIgE) to Dermatophagoides pteronyssinus, crab, cockroach, and moth. Results: The patients sensitized to shrimp were co-sensitized to D. pteronyssinus (88.7%), crab (85.4%), cockroach (89.2%), and moth (92.0%). Overall, 75% of the patients sensitized to shrimp tested positive to the above allergens; only four patients were sensitized to shrimp alone. The median (interquartile range [IQR]) concentrations of sIgE to shrimp (2.66 kU/L [1.02-6.11 kU/L] versus 1.61 kU/L [0.70-3.67 kU/L]), crab (2.35 kU/L [0.83-4.18 kU/L] versus 1.30 kU/L [0.59-3.14 kU/L]), cockroach (3.78 kU/L [0.98-6.91 kU/L] versus 1.56 kU/L [0.85-3.17 kU/L]), and moth (4.70 kU/L [2.98-9.62 kU/L] versus 2.85 kU/L [1.16-7.01 kU/L]) in patients with skin allergic diseases was significantly higher than in patients with respiratory allergic diseases (all p < 0.05). The median (IQR) concentration of sIgE to cockroach in the young adults (2.33 kU/L [0.86-5.56 kU/L]) was the highest among all age groups as well as to moth (young adults: 4.14 kU/L [1.93-8.24 kU/L]). With the increasing positive class of shrimp allergen, the sIgE concentration of moth, cockroach, and crab also increased, and the optimal scaling analysis showed that the sIgE of crab, cockroach, and moth had a strong correlation with sIgE to shrimp (Cronbach α = 93.8%). Conclusion: This study found a high rate of co-sensitization between moth, D. pteronyssinus, cockroach, and crab among patients sensitized to shrimp and a strong correlation between shrimp, moth, and cockroach. Shrimp and cockroach co-sensitization might be related to moth allergens.
Assuntos
Alérgenos/imunologia , Baratas/imunologia , Reações Cruzadas/imunologia , Imunoglobulina E/imunologia , Mariposas/imunologia , Penaeidae/imunologia , Hipersensibilidade Respiratória/imunologia , Hipersensibilidade a Frutos do Mar/imunologia , Dermatopatias/imunologia , Adolescente , Adulto , Idoso , Animais , Antígenos de Dermatophagoides/imunologia , Braquiúros/imunologia , Criança , Pré-Escolar , China , Dermatophagoides pteronyssinus/imunologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
Sensitization to allergens and their peptides varies among patients due to geographical or ethnic differences. The present study aimed to investigate immunoglobulin (Ig)E and IgG4 responses to tropomyosin and its peptides in shrimp allergic patients from northern China. A total of 92 subjects were studied, including 35 shrimp allergic patients, 29 patients with house dust mite (HDM) and/or cockroach allergic patients and 28 healthy volunteers. Serum IgE and IgG4 antibodies to recombinant shrimp tropomyosin (rPen a 1) and its peptides were measured by means of a lightinitiated chemiluminescent assay. A total of 9 major sequential epitopes of Pen a 1 reported in the literature were synthesized. Of 35 shrimp allergic patients, 25 (71.4%) had positive Pen 1specific IgE (sIgE) antibodies and 22 (62.9%) contained measurable rPen a 1specific IgG4 (sIgG4) antibodies. A strong IgG4 response accompanied the presence of IgE to Pen a 1. None of the patients with HDM and/or cockroach allergy demonstrated IgE reactivity to rPen a 1. The reaction frequency of IgE binding epitope was 2048%, while that of IgG4 binding epitope was 63.690.9%. The IgE and IgG4 recognition patterns of the tropomyosin peptides demonstrated high interpatient heterogeneity. Diversity of IgE binding epitopes was positively correlated with Pen a 1 sIgE levels. In the study population, tropomyosin was a major allergen recognized by the majority of shrimp allergic patients, which is consistent with previous reports. However, none of the 9 epitopes are major (reaction frequency >50%) IgEbinding regions, indicating the epitopes profile may be different in other regions.
Assuntos
Alérgenos/imunologia , Imunoglobulina E/imunologia , Imunoglobulina G/imunologia , Penaeidae/imunologia , Hipersensibilidade a Frutos do Mar/imunologia , Tropomiosina/imunologia , Adolescente , Adulto , Idoso , Animais , Criança , Pré-Escolar , China/epidemiologia , Epitopos/imunologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Hipersensibilidade a Frutos do Mar/epidemiologia , Adulto JovemRESUMO
Oysters are an important shellfish group known to cause food allergy; however, knowledge of their sensitization components and cross-reactivity is limited. This study aimed to identify a novel allergen in Crassostrea angulata and investigate its cross-reactivity. To this end, a 20 kDa protein was purified from oyster and confirmed to be a sarcoplasmic-calcium-binding protein (SCP) by LC-MS/MS. A 537 bp open reading frame was obtained from oyster SCP total RNA, which encoded 179 amino acids, and was expressed in Escherichia coli. According to the circular dichroism results, digestion assay, and inhibition ELISA, the recombinant SCP (rSCP) exhibited similar physicochemical properties and IgG-binding activity to native SCP. rSCP displayed stronger IgE-binding activity by immunological method. Moreover, a different intensity of cross-reactivity and sequence homology were demonstrated between shellfish species. Collectively, these findings provide novel insight into shellfish allergens, which can be used to aid in the in vitro diagnosis of oyster-sensitized patients.