Recent advances in the study of epitopes,allergens and immunologic cross-reactivity of edible mango

Mango(Mangifera indica L.)is a tropical fruit that is widely consumed as both fresh fruits and processed products around the world.The high incidence of mango allergy,on the other hand,has sparked widespread concern.Therefore,a summary and analysis of the current status and issues in mango allergen research can guide in-depth study on the mechanism of mango allergy and reveal effective desensitization methods.We described the incidence of fruit allergy,as well as the mechanism and clinical symptoms of mango allergy,in this review.We also looked into the structural properties of mango allergens,the effect of processing methods on mango allergens,prediction methods for mango allergen epitopes,and the current state of research on mango cross-reactive allergens and preventive measures.Finally,the research directions and ideas for the future are proposed and discussed.

Validation of Molecular Detection Methods for Gluten Allergens in Infant Formula

[Objectives]To verify the specificity,sensitivity,precision and negative-positive deviation of the foodproof gluten component de-tection kit for the detection of gluten allergens in milk powder matrix,and to establish a real-time fluorescent PCR legal method for the detec-tion of gluten allergens in milk powder.[Methods]The specificity,sensitivity,precision and negative-positive deviation of the detection method of foodproof gluten component detection kit(PCR-probe method)were verified by artificially adding different concentrations of wheat bran and extracting sample DNA by kit method,and applied to sample detection.[Results] The specific detection results of two kinds of milk powder with wheat bran and buckwheat added showed that the foodproof gluten component detection kit(PCR-probe method)had good speci-ficity for wheat gluten.The results of artificially added wheat bran positive samples showed that the false positive rate and false negative rate of the kit in the milk powder matrix were O,and the sensitivity and precision were high.[Conclusions]The kit is simple to operate and has high accuracy,which is suitable for the detection of gluten allergen components in milk powder.

The detection and regulation advances of food allergens

Food allergy has become an important food quality and safety issue,posing a challenge to the food industry and affecting consumer health.On the one hand,from the perspective of food processing industry,the diversity of food raw material ingredients,exogenous additives,and processing forms make the presence of allergens in modern food processing more complex.In addition,due to the lack of allergen identification,effective detection and allergenicity evaluation systems,there are serious deficiencies in the current theories and techniques for food allergen screening and detection,tracking and prediction,intervention and control;On the other hand,from the perspective of public health,meeting consumers'right to know whether there are raw materials containing food allergens in processed foods,and improving the credibility of government and people's satisfaction have become urgent matters;In addition,as people come into contact with more and more new borne novel foods,the probability of food allergy is also increasing.The food safety and health problems induced by increasingly complex,widespread and severe food allergy are difficult to avoid.In view of this,in response to the increasingly serious food allergy issues,this paper introduced the detection methods of food allergens,summarized the reduction and control techniques of food allergens,and elaborated hypoallergenic foods,which aims to provide the basis for preventing and controlling food allergy and ensuring the physical health of food allergy patients.

Allergenicity mitigation strategies of seafood allergens for hypoallergen

Introduction Seafood is a widely consumed and nutritionally rich food source,but it ranks among the top allergens,with shellfish and fish being major triggers of allergic reactions.These reactions,primarily caused by proteins such as tropomyosin(TM)in shellfish and parvalbumin(PV)in fish,can lead to life-threatening anaphylaxis in susceptible individuals.The development of hypoallergenic seafood is becoming increasingly important to provide safe alternatives for those with seafood allergies.This comment reviews recent advances in allergenicity mitigation strategies,highlighting the progress made and future potential in producing hypoallergenic seafood products.

Analysis of Allergens in 5473 Patients with Allergic Diseases in Harbin, China

Objective To analyze the allergic status to common inhalant allergens and food allergens in clinical patients in Harbin in northeastern China and provide evidence to develop the prevention strategy of allergic disease. Methods The data were collected from 5 473 patients with clinical suspected allergic diseases seeking medical care in the Second Affiliated Hospital of Harbin Medical University. Among these patients, 2 530 （46.2%） were males aged 0-86 years, the youngest was only 1 month old and 2 579 （47.1%） were young children and teenagers. The serum specific Immunoglobulin E （slgE） to 14 kinds of common allergens and serum total IgE were detected by using AllergyScreen test （Mediwiss Analytic GmbH, Moers, Germany）. Results In 5 473 subjects the positive rate of slgE was 33.1% （n=1 813）. Cow milk （6.9%） and wheat （3.1%） were the most common food allergens, followed by house dust mite mix （12.5%） and mould mix （9.4%） and the age and gender specific differences in the positive rate were significant. For the children aged 〈7 years the positive rates to cow milk, beef-mutton, and egg white/egg yolk were high, but the positive rates to house dust mite mix, ragweed estragon, and mould mix were low （P〈0.05）. For the adults the positive rates to aeroallergens were high while the rates to food allergens were low. Conclusion The results from this study showed that the food allergens in Harbin had geographic characteristics, which support the viewpoint that the environment factors play an important role in the incidence of allergic diseases. Also, the detection of slgE and total IgE are essential to identify relevant allergens for the purpose of early diagnosis, management and prevention of allergic disease.

A Study on Pollen Allergens in China

Objective Allergic disease caused by airborne pollen is a major health problem in China. Intensive study on pollen allergens can be of great help for preventing and treating pollinosis. Four aspects of the study on pollen allergens in China including major allergic pollen in our country, analysis and purification of pollen allergen composition, recombinant pollen allergens and clinical application of pollen allergens are described in this paper.

Cross-reactivity between aeroallergens and food allergens

In patients with respiratory allergy,cross-reactivity between aeroallergens and foods may induce food allergy,symptoms ranging from oral allergy syndrome to severe anaphylaxis.Clinical entities due to Ig E sensitization to cross-reactive aeroallergen and food allergen components are described for many sources of plant origin(pollen-food syndromes and associations,such as birch-apple,cypress-peach and celery-mugwortspice syndromes,and mugwort-peach,mugwortchamomile,mugwort-mustard,ragweed-melon-banana,goosefoot-melon associations),fungal origin(Alternariaspinach syndrome),and invertebrate,mammalian or avian origin(mite-shrimp,cat-pork,and bird-egg syndromes).Clinical cases of allergic reactions to ingestion of food products containing pollen grains of specific plants,in patients with respiratory allergy to Asteraceae pollen,especially mugwort and ragweed,are also mentioned,for honey,royal jelly and bee polen dietary supplements,along with allergic reactions to foods contaminated with mites or fungi in patients with respiratory allergy to these aeroallergens.Medical history and diagnosis approach may be guided by the knowledge about the diverse cross-reacting allergens involved,and by the understanding of these clinical entities which may vary significantly or may be overlapping.The association between primary Ig E sensitization with respiratory symptoms to inhaled allergens and food allergy due to cross-reactive allergen components is important to assess in allergy practice.The use of molecular-based diagnosis improves the understanding of clinically relevant Ig E sensitization to cross-reactive allergen components from aeroallergen sources and foods.

Detection and inactivation of allergens in soybeans:A brief review of recent research advances

In the last decade,soybean allergies have been on the increases to such an extent that they have now become a public health issue thus prompting more studies and researches on the topic.The allergenicity of soybean is attributed to its protein fraction.The best way to prevent hypersensitive patients from ingesting allergenic compounds is to exclude such soybean allergens from their diet.As a result,it is essential to provide detailed and reliable knowledge of food ingredients.Therefore,precise and reliable approaches for detecting soybean allergens found in various food products must be used.The main way to reduce allergy risk is the identification of allergenic sites in food and their inactivation by various food-processing methods.It has been reported that food processing may lead to the modification of conformational structure of the protein or protein distortion that inhibit the binding of immunoglobulin E(Ig E)to epitopes on food allergens and also the mechanism of allergic reactions.Food processing technologies employed for inactivating allergenic epitopes used thermal and nonthermal techniques.Currently,several detection methods including protein-based and DNA-based approaches using analytical techniques such as enzyme-linked immunosorbent assay(ELISA),enzyme allergosorbent test(EAST),radioallergosorbent test(RAST),lateral flow immunoassay(LFIA),immunoblotting,realtime polymerase chain reaction(PCR),mass spectrometry and biosensors have been improved for identifying and quantifying these epitopes.This research focused on allergenic proteins of soybean,the most modern approaches for detecting and quantifying these allergens,and finally,the various methods used to inactivate these proteins and their effects on soy allergenicity.

IgE Reactivity of Potential Allergens from the Swimming Crab Portunus trituberculatus and the Research of ELISA Reagent for Detecting Crab Food Anaphylaxis

Crustacean is one of the major allergic foods.It is of great significance to identify more crab allergens and research the detection methods for crab food anaphylaxis.In this study,IgE reactivity to three recombinant proteins from Portunus trituberculatus,including tropomyosin(rPtTM),myosin light chain(rPtMLC),and pancreatic lipase(rPtPL),were detected by enzyme-linked im-munosorbent assay(ELISA).The expressions of tropomyosin(TM)in various tissues of P.trituberculatus were detected by Western blot(WB).Furthermore,microplates were coated with rPtTM and the ELISA conditions were optimized.The cut-off value was deter-mined by the receiver operating characteristic(ROC)curve.Among 51 crab-allergic sera,21(41.2%)showed positive IgE to rPtTM.Other 70 crab-allergic sera more frequently recognized rPtPL(9/70;12.9%),followed by rPtMLC(1/70;1.4%).WB results showed that TM was mainly expressed in the muscle,followed by the heart and a small amount in gills and the testis.The optimal results showed that the coating condition of rPtTM was 50 ng per well with coating for 3 h at 37℃.The optimal blocking condition was 1.2%BSA with blocking for 3 h at 37℃,and the optimal dilution of the second antibody was 1:1500.The ROC curve showed that the ELISA reagent had high sensitivity(83.52%)and specificity(98.00%)when the cut-off value was 0.45.All results indicated that tropomyosin is the major allergen of P.trituberculatus,and myosin light chain and pancreatic lipase are the potential allergens.Addi-tionally,the ELISA reagent developed with the rPtTM was feasible for laboratory detection of crab anaphylaxis.

Food Allergens and Food Safety： A Global Perspective with Respect to Codex Alimentarius

Over the last two decades, food allergens are being recognized as one of the food hazards. This serious food safety issue is being addressed in different countries not only in terms of their biological and clinical characteristics, but also in terms of various standards of allergen management in food industries. This abnormal immune response caused by food allergens affects the quality of life especially in children and influences their overall health and retards normal growth, along with they suffer from ailments like eating disorders, depression, sometimes even death which is the most adverse impact of food allergy. Every country has their own set of guidelines to deal with the food allergens especially developed countries, food allergen guidelines is not well documented in developing countries. FAO/WHO is providing assistance to developing countries in strengthening their food safety guidelines. The Codex Alimentarius was formulated by the two organizations FAO/WHO in the year 1960; it is a collection of food standards in a integrated, codified style, together with associated material such as codes of hygiene and good manufacturing practices that should be followed by industries during various production stages of a food item. In both developed and developing nations, the Food Chemical Codex or the Codex Alimentarius aims to protect public health and implement fair trade practises for the trading of food items.

Induced Immunity of Response to Some Allergens Towards Response of Other Skin Test Allergens and Its Correlation with Immediate Hypersensitivity Reactions

Allergens are innocuous environmental antigens that cause lgE mediated hypersensitivity reactions. These antigens can be divided into several groups according to their nature like plant allergens, grasses, fungal allergens, pollen grains and house dust mite. Skin response to such allergens is associated with each other either by positive relation （positive correlation） or negative （inverse） relation. No previous papers found to discuss such correlations. In order to investigate these correlations, skin prick test of standard allergens solutions was carried out in 500 patients suffering allergic reactions of the age 12-60 years of both sexes. The results showed that there is a high significance of positive and negative correlations in skin response to allergens in the same group and with allergens of different groups suggesting that there is an induction or suppression of immune response. In conclusion the similarity or dissimilarity in the primary structure of some allergens in addition to gene-environment interaction may reflect positive/negative correlations between certain allergens that can influence the related allergic reactions.

Peanut Allergens Attached with p-Aminobenzamidine Are More Resistant to Digestion than Native Allergens

Despite being known as resistant proteins, peanut allergens (Ara h 1 and Ara h 2) can be digested and cause allergic reactions. Making the allergens more resistant to digestion may aid in non-absorption and excretion of the allergens. Our objectives were to make Ara h 1 and Ara h 2 more resistant to digestion and test them in a model system using trypsin as the digestive enzyme. The resistant allergens were prepared by covalently attaching p-aminobenzamidine (pABA), a protease inhibitor, to peanut allergens in an extract or on a PVDF membrane using glutaraldehyde, and were then tested for resistance to trypsin digestion. SDS-PAGE and Western blot were performed to determine the allergenic capacity of the modified allergens. A control was prepared using glycine instead. Results showed that Ara h 2, when covalently attached with pABA, was more resistant to trypin digestion than the native allergen. Similarly, Ara h 1, prepared on a PVDF membrane and treated with pABA, displayed a resistance to trypsin digestion. Treatment of the allergens with glycine (a control) instead of pABA showed that the modified allergens were as digestible as native allergens. Blot assays showed that the pABA-treated allergens exhibited a lower allergenic capacity than native allergens. It was concluded that pABA, when attached to peanut allergen Ara h 1 or Ara h 2, inhibited digestion of the allergen by trypsin and reduced their allergenic capacity as well.

In Silico Analysis of the Cross-Reactivity of Pacific White Shrimp (Litopenaeus vannamei) Allergens with Other Arthropod Species

This study provided new data in the area of cross-reactivity for Pacific white shrimp (Litopenaeus vannamei). Although the cross-reactivity between the most prominent allergenic proteins of shrimp and other crustaceans has been extensively studied, few data are showing the frequency of arthropod-shrimp Litopenaeus vannamei cosensitization in an in silico analysis. A comparative analysis of “typical and non-typical” shrimp L. vannamei allergens with other species was achieved, revealing new allergens and previously characterized shrimp allergens, which validated the comprehensive identification approach used in this study. Importantly, up to 192, amino acid sequences were identified that had matches to shrimp L. vannamei allergens that matched allergenic proteins in mites, insects, fish, bacteria, mammals, birds, and plants.

Determination of 24 Allergens in Perfume with High Performance Liquid Chromatography Tandem Mass Spectrometry

A method of 24 allergens determination in cosmetics were established with high performance liquid chromatography tandem mass spectrometry. The targeted compounds were extracted with acetonitrile and determined with LC-MS/MS (MRM mode) with external method. The linearity between concentrations and peak area ratio was obtained from 1.0~5.0 mg/L. The limits of detection were 1.0 mg/L for the instrument and 5.0 mg/kg for the method respectively. The LOQ was 15.0 mg/L. The average recoveries of 24 allergens were between 85.9% and 110.0% at spiked levels of 5, 10 and 20 mg/kg with relative standard derivation (RSDs) of 5.5%~12.0%(n=10). The method could be used as a reliable means for simultaneous quantitative determination of allergens in cosmetics.

Major allergens in 8 types of allergenic foods and allergen detection techniques

In recent years,the prevalence of allergens in food warning notices,both domestically and internationally,has become the second leading concern after microbial contamination.Among the various factors that threaten human health reported by the World Health Organization,food allergy ranks fourth,and food allergy has become a global security problem.As of now,no definitive treatment for food allergies exists,making the avoidance of allergen-containing foods the most effective prevention method.Consequently,labeling foods with allergen information serves as a crucial warning for allergic populations.Moreover,to enhance comprehension of food allergies,this article provides a brief overview of their definition and sensitization mechanisms.The main focus lies in highlighting the structure of primary allergens found in eight commonly allergenic foods and the resulting clinical symptoms they cause.Additionally,a summary of commonly employed allergen detection techniques is presented,with an analysis of their principles,advantages,and limitations.Looking ahead,the integration of diverse technological approaches to establish an efficient,accurate,and affordable allergen detection method remains a significant trend.This article has certain reference value for understanding the direction of food allergies.

Comprehensive characterization and detection of nut allergens in bakery foods using Q-TOF mass spectrometry and bioinformatics

Food allergy is a growing health issue worldwide and the demand for sensitive,robust and high-throughput analytical methods is rising.In recent years,mass spectrometry-based methods have been established for multiple food allergen detection.In the present study,a novel method was developed for the simultaneous detection of almond,cashew,peanut,and walnut allergens in bakery foods using liquid chromatography–mass spectrometry.Proteins unique to these four ingredients were extracted,followed by trypsin digestion,quadrupole time-of-flight(Q-TOF)mass spectrometry and bioinformatics analysis.The raw data were processed by de-novo sequencing module plus PEAKS DB(database search)module of the PEAKS software to screen peptides specific to each nut species.The thermal stability and uniqueness of these candidate peptides were further verified using triple quadrupole mass spectrometry(QQQ-MS)in multiple reaction monitoring(MRM)mode.Each nut species was represented by four peptides,all of which were validated for label-free quantification(LFQ).Calibration curves were constructed with good linearity and correlation coefficient(r 2)greater than 0.99.The limits of detection(LODs)were determined to range from 0.11 to 0.31 mg/kg,and were compared with the reference doses proposed by Voluntary Incidental Trace Allergen Labelling(VITAL).The recoveries of the developed method in incurred bakery food matrices ranged from 72.5%to 92.1%with relative standard deviations(RSD)of<5.2%.The detection of undeclared allergens in commercial bakery food samples confirmed the presence of these allergens.In conclusion,this method provides insight into the qualitative and quantitative detection of trace levels of nut allergens in bakery foods.

Synthesis and Degradation of the Major Allergens in Developing and Germinating Soybean Seed

Gly m Bd 28K, Gly m Bd 30K and Gly m Bd 60K are the major soybean （Glycine max （L.） Merr.） allergens limiting the consumption of a good protein source for sensitive individuals. However, little is known about their temporal-spatial expression during seed development and upon germination. The present data shows that soy allergens accumulated in both the embryonic axes and cotyledon, but expression patterns differed depending on the specific allergen. Allergens accumulated sooner and to a greater level in cotyledons than in embryonic axes. Gly m Bd 28 began at 14 d after flowering, 7 to 14 d earlier than Gly m Bd 30K and Gly m Bd 60K. Comparatively, their degradation was faster and more profound in embryonic axes than in cotyledons. Gly m Bd 60K began to decline at 36 h after imbibition and remained detectable up to 108 h in cotyledons. In contrast, the Glym Bd 60K protein was reduced at 24 h, and eventually disappeared at 96 h. In cotyledons Gly m Bd 28K first declined at 24 h, then increased from 36 h to 48 h, followed by its large reduction at 72 h after seed germination. These findings provide useful information on soy allergen biosynthesis and will help move forward towards developing a hypoallergenic soybean for safer food.

Molecular Characteristics of Cockroach Allergens

Cockroaches, commonly found in urban dwellings worldwide, have long been considered vectors of various infectious diseases and cockroach allergens are one of the major etiologic risk factors for IgE-mediated allergic respiratory illness throughout the world. A high prevalence of cockroach hypersensitivity in atopic （20-55 %） and asthmatic （49-60 %） populations has been documented. Cockroach allergens with molecular weights ranging from 6 to 120 kD have been identified by various standard immunochemical techniques. This article covers the characteristics of major cockroach allergens that have been purified, sequenced, cloned, and produced as recombinant proteins. Cellular ＆ Molecular Immunology. 2005;2（3）： 177-180.

Studies on the Specific Degranulation of Mast Cell Sensitized by Several Allergens in vitro

Food allergy is a major health issue worldwide. Mast cells play a very important role in the immediate hypersensitivity for which mast cell degranulation needs to be studied extensively. In this study, an approach was taken to study the characteristics of sensitized mast cell degranulation in vitro, which associated with the study of mast cells and animal models. BALB/c mice were immunized respectively by several food allergens, then blood and peritoneal mast cells were collected at different time points. A dynamic determination was carried out between mast cells and serumal IgE. Comparative analysis on sequential time points showed that there was a close coincidence between mast cell degranulation and IgE antibody titers in sensitized BALB/c mice. Furthermore, it is interesting that sensitized mast cells could implement specific degranulation against the challenges in vitro, but the closely tropomyosins induced mast cell degranulation displayed cross reactions. This is very similar to IgE resisting the allergens in vivo. The study disclosed some characteristics on mast cells, coming from sensitized BALB/c mice, degranulation in vitro.

Prevalence of sensitivity to cockroach allergens and IgE crossreactivity between cockroach and house dust mite allergens in Chinese patients with allergic rhinitis and asthma

Background Cockroaches are an important indoor allergen source causing allergic rhinitis and asthma. The aim of this study was to investigate the cockroach prevalence in mainland of China and the cross-reactivity of IgE between cockroach and house dust mite allergen in Chinese patients.Methods The cockroach sensitization pattern was based on a skin prick test （SPT） obtained from a national multicenter prevalence study, in which 6304 patients from 25 allergy centers across China participated. Factors, including different regions of China, age, gender and the correlations between the American and German cockroaches and house dust mite Der p were investigated. Eighteen out of 1236 clinical sera from south China were selected to perform the cross-inhibition assay between house dust mites and cockroaches.Results Totally 25.7% of patients were SPT positive to the American cockroach （Periplaneta Americana, Per a） and 18.7% SPT positive to the German cockroach （Blattella germanica, Bla g）. The prevalence of positive cockroach SPT was higher in southern than in northern China, higher in adults than in children, and higher in males than in females.Patients had relatively low levels of cockroach SPT reactions, mainly class 1 or 2. Of the SPT positive cockroach patients,88% were also SPT positive to house dust mite （Dermatophagoides pteronyssinus, Der p）. An IgE cross-inhibition study confirmed that Der P sensitization could cause false positive SPT reactions against cockroach.Conclusions A relatively high prevalence of cockroach sensitivity was found in mainland of China. However, a cross-inhibition study showed that only a small number of patients appear to have Bla g and/or Per a as primary sensitizing source. The importance of cockroaches as a risk factor for sensitization and triggers of allergic symptoms in mainland of China needs to be further investigated.