Shrimp Allergen Research Articles

Effects of Glycosylation Combined with Phosphate Treatment on the Allergenicity and Structure of Tropomyosin in Litopenaeus vannamei.

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.

Rapid and sensitive detection of shrimp allergens within 30 min using a new food nucleic acid release agent combined with a fast real-time PCR assay

To achieve fast on-site detection of shrimp allergens in food, this study established a new direct, fast, and real-time quantitative polymerase chain reaction (PCR) technology. The technology completed nucleic acid extraction in 4 min using a new nucleic acid releaser, and the DNA samples were detected using fast qPCR within 25 min (total detection was approximately 30 min). The results indicated that the direct fast qPCR can specifically detect shrimp, with a limit of detection of 0.0001% of shrimp in artificially simulated meat samples and a detection precision variation coefficient (CV value) was less than 5%. It successfully identified shrimp in different types of commercial food samples. As a simple, fast, and sensitive nucleic acid testing technology, it has broad application prospects for the on-site detection of shrimp allergens in food.

Variation in Shrimp Allergens: Place of Origin Effects on Food Safety Assessment.

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.

A SILAC-based accurate quantification of shrimp allergen tropomyosin in complex food matrices using UPLC-MS/MS

The carryover of trace allergens in complex food matrices poses challenges for detection techniques. Here, we demonstrate an accurate UPLC-MS/MS quantification assay for the shrimp allergen tropomyosin with a full-length isotope-labelled recombinant tropomyosin (TM-I) internal standard in complex food matrices. The TM-I, expressed based on the SILAC technique, exhibited a high isotope labelling ratio (>99%), purity, and alignment with the natural sequence. This method determined the tropomyosin ranging from 0.2 to 100 ng/mL. Mean recoveries ranged from 89 to 116%, with intra- and inter-day RSDs below 12%, for three signature peptides across three types of commercially processed food matrices. The limits of quantitation were 1 μg/g in pop food and sauce, and 10 μg/g in surimi product, respectively. This study supports the use of recombinant full-length isotope-labelled proteins rather than stable-isotope labelling peptides as internal standards to achieve more accurate quantitation of food allergens as the digestion error is corrected.

Genomics of Shrimp Allergens and Beyond.

Allergy to shellfishes, including mollusks and crustaceans, is a growing health concern worldwide. Crustacean shellfish is one of the "Big Eight" allergens designated by the U.S. Food and Drug Administration and is the major cause of food-induced anaphylaxis. Shrimp is one of the most consumed crustaceans triggering immunoglobulin E (IgE)-mediated allergic reactions. Over the past decades, the allergen repertoire of shrimp has been unveiled based on conventional immunodetection methods. With the availability of genomic data for penaeid shrimp and other technological advancements like transcriptomic approaches, new shrimp allergens have been identified and directed new insights into their expression levels, cross-reactivity, and functional impact. In this review paper, we summarize the current knowledge on shrimp allergens, as well as allergens from other crustaceans and mollusks. Specific emphasis is put on the genomic information of the shrimp allergens, their protein characteristics, and cross-reactivity among shrimp and other organisms.

The effect of papain hydrolysis on tropomyosin levels in shrimp

Shrimp allergy is a serious public health problem. Epidemiological studies indicated the main cause of food allergy is the ingestion of shrimp and crab. Consequently, reducing the risk of shrimp and crab allergy is a major research focus. Few studies have demonstrated the effect of enzyme hydrolysis on reduction of shrimp allergens in food. In this study, we used papain, a commonly used enzyme in the food industry, as an ingredient to decrease levels of allergen tropomyosin in shrimp. 0–50U of papain was used to treat the shrimp meat, and then heated to measure the levels of tropomyosin, and determined the change of the protein secondary structure. The results showed that 20U of papain decrease the tropomyosin levels up to 80 %, which was further enhanced when combined with 3 min of heating. Furthermore, the result of Fourier-transform infrared spectroscopy (FTIR) showed alteration of secondary protein structure after the processing. The processing developed in this study may be an effective method used to change the levels and structure of tropomyosin.

A study of allergen detection panel in Guangzhou, southern China based on real-world data from the past 7 years

This study aims to reduce the cost of allergen testing for Guangzhou, China by limiting the number of allergens for which patients are tested, and provide a testing panel to improve diagnostic and therapeutic efficiency. This retrospective study of real-world data from 2012 to 2019 included 39,570 patients with suspected allergies in Guangzhou, southern China. All the patients were tested for one or more of the following allergens serum specific immunoglobulin E (sIgE): Dermatophagoides pteronyssinus, Dermatophagoides farinae, cat dander, dog dander, Artemisia vulgaris, Aspergillus fumigatus, Alternaria alternata, Blattella germanica, egg whites, milk, wheat, peanuts, soybeans, Cancer pagurus, and Penaeus monodon by PhadiaCAP 1000. Totally, only the positive rates of allergens sIgE in D. farinae, D. pteronyssinus, milk, egg whites, B. germanica, C. pagurus, A. alternata, and P. monodon were > 10%, the other allergens were between 4–7%. Moreover, among the allergic diseases, dust mites exhibited the overall highest positive rate, followed by milk and B. germanica. In children, milk was the main allergen, whereas in adults, mites, cockroaches, shrimp, and crab allergens had higher positive rates. The optimal scale analysis shows that the multiple sensitization classification of patients can be divided into three categories: I D. farinae and D. pteronyssinus; II. C. pagurus, P. monodon, and B. germanica; III. Milk and egg whites. Generally, a panel including 4 allergens can detect > 90% of the potential allergy in this local population. In Guangzhou, southern China, D. farinae, milk, B. germanica, and A. alternata as a panel screening allergy for suspected allergic patients was suggested base on this study.

Research of the Protein Profile and Allergenic Properties of the Tropomyosin and Other Allergenic Components in the Composition of Water-Salt Extract of Giant Tiger Shrimp (<i>Penaeus monodon</i>)

Despite the success in identifying new crustacean allergens other than tropomyosin, many potential allergens remain unidentified. At present there are no diagnostic and treatment crustaceans allergens on the Russian market, including tropomyosin of invertebrates. The aim of the research was to explore allergenic properties of tropomyosin and other proteins in water-salt extract from tiger shrimp (Penaeus monodon). Raw and boiled meat of giant tiger shrimp was used to prepare allergenic extracts. To identify the specific activity of experimental allergens, sera from patients allergic to crustaceans with an established degree of activity (class 3) were used. The levels of specific IgE were from 3.5 to 17.5 IU/mL. ELISA was performed with the allergen samples. Polyacrylamide gel electrophoresis of raw and boiled shrimp allergen preparations was followed by Western blotting with the most allergen-specific serum. It has been shown that the extracts from raw and boiled shrimp have allergenic activity (bind IgE). The heat treatment of shrimp had no effect on allergenic activity except for one sample, where a strong reaction with the antigens was found. It is proved that the selected extraction conditions make it possible to reveal the multifractional nature of the protein profile of raw and boiled shrimp extracts. In Western blotting experiments the raw shrimp extract showed a weak reaction; tropomyosin was not detected. At the same time five protein fractions were identified in the boiled shrimp samples which reacted with IgE antibodies of a patient with crustaceans’ allergy. The data obtained will allow us expanding the knowledge about crustacean allergy and continueing our research to determine the optimal conditions for cleaning shrimp allergens.

Immunological comparison of recombinant shrimp allergen Pen m 4, produced in Pichia pastoris and Escherichia coli.

Shellfish are a leading cause of allergies worldwide, affecting about one-tenth of the general population. The sarcoplasmic calcium-binding protein, also known as allergen Pen m 4, is an important factor in shrimp allergies. Our objective was to assess the most effective techniques for producing a recombinant Pen m 4 protein as a potential tool for diagnosing shrimp allergies. In this study, for the first time, we produced a functional recombinant Pen m 4 protein in a eukaryotic system, Pichia pastoris, and analyzed it against Escherichia coli-produced equivalents in enzyme-linked immunosorbent and reverse-phase protein microarray assays. A dual tag system based on the maltose-binding protein was successfully used to increase the yield of Pen m 4 by 1.3 to 2.3-fold in both bacteria and yeast, respectively. Immunological characterization showed that N-glycosylation is neither crucial for the folding of Pen m 4 nor its recognition by specific IgE. However, the Ca2+-depletion assay indicated a dependence on calcium ion presence in blood samples. Results demonstrate how a comparative analysis can elucidate essential allergen manufacturing points. In conclusion, E. coli-produced Pen m 4 protein fused with the maltose-binding protein should be the preferred option for further studies in Penaeus monodon allergy diagnostics.

Reduced Allergenicity of Shrimp (Penaeus vannamei) by Altering the Protein Fold, Digestion Susceptibility, and Allergen Epitopes.

The mechanism by which thermal/pressure processing influences the allergenicity of shrimp (Penaeus vannamei) was explored by anaphylaxis in mice, the protein structure, gastrointestinal digestion, and linear epitopes. Roasting induced the unfolding of the structure, which may reduce the allergenicity, but it made more linear epitopes to be exposed, causing mice to exhibit similar systemic anaphylaxis as mice fed with the raw shrimp protein (p > 0.05). However, the roasted + reverse-pressure-sterilized shrimp can significantly reduce specific antibodies, mast cell degranulation, vascular permeability, and histopathological morphology in mice compared with the raw and roasted shrimp (p < 0.05) because reverse-pressure sterilization causes protein to aggregate, hiding the heat/digested stable epitopes of arginine kinase (Glu59-Ser63, Asn112-Lys118, Leu131-Phe136, and Ser158-Glu162) and sarcoplasmic calcium-binding protein (Asn57-Phe67, Ser159-Cys165, and Glu126-Ala130) inside a 3D structure, while gastrointestinal digestion can destroy immunodominant, minor epitopes and the epitopes exposed by roasting. Meanwhile, the low binding frequency of IgE to troponin C was also responsible for maintaining the hypoallergenicity of shrimp.

Litopenaeus vannamei fermentation using selected Lactobacillus spp. to reduce its allergenicity

ABSTRACT Shrimp is a common cause of food allergies in allergic individuals. The management of patients suffering from shrimp allergy relies on avoidance of the specific food, which compromises nutritional requirements. In this study, fermentation was performed using Lactobacillus to reduce the allergenicity of Litopenaeus vannamei. The optimal fermentation conditions using Lactobacillus helveticus TS6024 were 1% glucose, 30% minced shrimp, 2.5% inoculum level, 3% NaCl, and 60 h of incubation at 37°C, whereas those using Lactobacillus acidophilus 6005 were 2% glucose, 20% minced shrimp, 15% inoculum level, 2% NaCl, and 48 h of incubation at 42°C. Under optimal conditions, Lactobacillus helveticus TS6024 and Lactobacillus acidophilus 6005 fermentation reduced the allergenicity of shrimp by 78.97% and 70.09%, respectively. SDS-PAGE analysis showed that the band intensity of tropomyosin (36KDa) reduced evidently after the selected Lactobacillus fermentation. The hypoallergenic shrimp/shrimp products will provide optimal nutrition with reduced risk of adverse reactions in hypersensitive individuals.

Development of gastro-food allergy model in shrimp allergen extract-induced sensitized mice promotes mast cell degranulation.

Food allergies have become more common in the last decade. Shrimp is one of the most dominant food allergy triggers in Asian countries, including Indonesia. After ingesting allergens, B cells will produce allergen-specific Immunoglobin E (IgE). In the sensitization period, repeated allergen exposure promotes Mast Cell (MC) degranulation in intestinal tissue and releases several inflammatory mediators, thereby causing hypersensitivity reactions. Shrimp Allergen Extract (SAE) is an immunotherapy and diagnostic agent currently being developed in Indonesia. In this study, we investigated the effect of SAE administration on eliciting an MC immunological response. Mice were divided into a non-sensitized and sensitized group. The non-sensitized group only received 1 mg of alum (i.p), whereas the sensitized group received 1 mg of alum and 100 μg of SAE on days 0, 7, and 14. Then, both groups were challenged with 400 μg SAE (p.o) on days 21, 22, and 23 following systemic allergic symptom observation. We showed that SAE was able to increase systemic allergic symptoms significantly in the sensitized mice through repeated challenge (1.33±0.21; 1.83±0.17; and 2.00±0.00), compared to non-sensitized mice (0.17±0.17). Moreover, histopathological analysis showed that the SAE administration causes an increase of MC degranulation in the ileum tissue of the sensitized mice (44.43%±0.01), compared to non-sensitized mice (35.45%±0.01). This study found that SAE could induce allergic reactions in mice by influencing critical effector cells, MCs.

Stability of Major Shrimp Allergens in a Food Manufacturing Facility for Drug Delivery

Understanding the stability of the shrimp allergen tropomyosin (TM) in shrimp powder at different temperatures is necessary to develop shrimp oral immunotherapy (SOIT). We evaluated the shrimp TM stability for different storage times for utilization in a SOIT clinical trial and determined the specific IgE (sIgE) binding capacity of raw and cooked shrimp allergen extracts.

Alteration of the Transcriptome in Response to Shrimp Allergens in Shrimp Allergic Peripheral Blood Mononuclear Cells

Molecular cellular pathogenesis in shrimp allergy remains incompletely understood. In this study, we reveal the transcriptome from a single cell analysis in response to major shrimp allergen tropomyosin in total peripheral blood mononuclear cells (PBMCs) from shrimp allergic (SA) and control patients.

Alteration of Cellular and Cytokine Profiles in Response to Shrimp Allergens in Peripheral Blood Mononuclear Cells from Shrimp Allergic Patients

The cellular immune responses to shrimp allergen have not been completely characterized. We hypothesized different patterns of cytokines in responses to raw and cooked shrimp allergens would occur from total shrimp allergic (SA) patient PBMCs compared to healthy controls.

Effectiveness of Shrimp Allergenic Extract as an Immunotherapy Agent in Mice Model of Gastrointestinal Allergy

Allergen extract as allergen-specific immunotherapy (AIT) is the only causative therapy and provides protection or tolerance to an allergen in the long term. However, allergen extracts from different countries may have different effectiveness. This study aimed to evaluate the effectiveness of Indonesian shrimp allergen extract (SAE) as an immunotherapy agent with a mouse model of allergies in the gastrointestinal tract. Mice were divided into five groups consisting of the naïve group, allergic group, and the allergic group received SAE immunotherapy at high dose (100µg/week), moderate dose (50µg/week), and low dose (10µg/week). Each group received treatment in the sensitization and desensitization phases, which was then followed by an oral challenge of SAE 100µg. The effectiveness of SAE immunotherapy was assessed based on the parameters of systemic allergic symptoms, IL-10 mRNA expression in ileum tissue, and IgG2a serum concentration. We found that SAE immunotherapy decreased the systemic allergic symptoms score, regardless of dosage, and the effect persisted on the third challenge. IgG2a as a parameter of humoral immunity showed a significant increase in the high-dose immunotherapy group, and IL-10mRNA expression as a parameter of cellular immunity also showed an increase in the high-dose group. Both data showed a dose-dependent manner. It can be concluded that SAE has excellent effectiveness as an immunotherapy agent and dose-dependent characteristics.

Changing the IgE Binding Capacity of Tropomyosin in Shrimp through Structural Modification Induced by Cold Plasma and Glycation Treatment

Tropomyosin (TM) is the major allergen of shrimp (Penaeus chinensis). Previous studies showed that separate cold plasma or glycation have their drawback in reducing allergenicity of TM, including effectiveness and reliability. In the current study, a new processing combining cold plasma (CP) and glycation was proposed and its effect on changing IgE binding capacity of TM from shrimp was investigated. Obtained results showed the IgE binding capacity of TM was reduced by up to 40% after CP (dielectric barrier discharge, 60 kV, 1.0 A) combined with glycation treatment (4 h, 80 °C), compared with the less than 5% reduction after single CP or glycation treatment. Notably, in contrast to the general way of CP prompting glycation, this study devised a new mode of glycation with ribose after CP pretreatment. The structural changes of TM were explored to explain the decreased IgE binding reactivity. The results of multi-spectroscopies showed that the secondary and tertiary structures of TM were further destroyed after combined treatment, including the transformation of 50% α-helix to β-sheet and random coils, the modification and exposure of aromatic amino acids, and the increase of surface hydrophobicity. The morphology analysis using atomic force microscope revealed that the combined processing made the distribution of TM particles tend to disperse circularly, while it would aggregate after either processing treatment alone. These findings confirmed the unfolding and reaggregation of TM during combined processing treatment, which may result in the remarkable reduction of IgE binding ability. Therefore, the processing of CP pretreatment combined with glycation has the potential to reduce or even eliminate the allergenicity of seafood.

Extended IgE profile of shrimp-sensitized patients based on Multiplex Examination ALEX2 - Allergy Explorer.

The key to the correct diagnosis of shrimp allergy is a qualification to the most efficient diagnostic method and later interpretation of the result. To achieve this, it is necessary to apply a diagnostic strategy relevant to each patient's clinical situation and approach every case individually. In this study the allergen profile of shrimp-sensitized patients was analysed using ALEX2 Allergy Explorer. This study includes 50 adult patients with positive prick-by-prick tests with tiger shrimp bought from the local eco-market and an elevated concentration of IgE specific to the shrimp allergen extract (ImmunoCap). A total of 35 patients with negative skin prick tests with shrimp and not detectable sIgE shrimp in ImmunoCap were included in the control group. All patients had ALEX2 Allergy Explorer microarray test. In the shrimp-sensitized group, 22 patients were sensitized to at least one allergen component of Penaeus monodon, 20 patients were sensitized to crab, and 20 were sensitized to lobster. Only 15 (30%) patients were sensitized to the Northern prawn (Pandalus borealis) allergen extract in ALEX2 and only 12 (24%) to Shrimp mix (Litopenaeus setiferus, Farfantepenaeus aztecus, Farfantepenaeus dourarum). Sensitization to shrimp tropomyosin in the research group was present only in 34% of cases. There may be other shrimp allergen components, not available in ALEX2, which are responsible for shrimp sensitization.

Skin Prick Test Profile: A Retrospective Study

Background: A skin prick test is one method to detect allergies. Skin prick testing in dermatology can be performed on atopic dermatitis and urticaria. Skin prick test can be done easily, it’s relatively safe, fast, and can use many allergens simultaneously in one test. Purpose: To describe the characteristics of the skin prick test results at the clinic of Dermatology and Venereology, Mohammad Hoesin Palembang General Hospital, for the period 2016-2021. Methods: Descriptive retrospective study using a cross-sectional approach. Medical record data for the period January 2016-December 2021. Result: The number of patients who underwent skin prick testing during the period January 2016 to December 2021 was 116 patients, dominated by women (59.5%) and those aged 26-35 years (40.5%). The majority of diagnoses examined were atopic dermatitis (48.3%) and chronic urticaria (31.9%). The most positive results were for allergens in the form of house dust mites, shrimp, and crabs. The positive proportion of milkfish allergen was higher in women, while the positive proportion of shrimp allergen was higher in men. Chicken feather allergen showed significant differences between the diagnoses of atopic dermatitis, chronic urticaria and acute urticaria. Conclusion: House dust mites were the dominant allergen in patients with atopic dermatitis, chronic urticaria, and acute urticaria. skin prick test is recommended to be performed in the management of atopic dermatitis, chronic urticaria, and acute urticaria in order to detect the allergen because it has significant clinical relevance.

Mechanism of the reduced allergenicity of shrimp (Macrobrachium nipponense) by combined thermal/pressure processing: Insight into variations in protein structure, gastrointestinal digestion and immunodominant linear epitopes

This study aimed to explore the underlying mechanism about combined thermal/pressure processing on the allergenicity of shrimp (Macrobrachium nipponense). We analysed sensitizing and eliciting capacities, structural changes, gastrointestinal digestion, and mapped linear epitopes. Mice treated with steamed + reverse-pressure sterilized shrimp exhibited lower specific IgE and IgG1 concentrations, degranulation, vascular permeability, and allergic symptoms than those fed with raw shrimp or steamed shrimp (p < 0.05). Reduced allergenicity of shrimp using combined thermal/pressure processing was not only associated with protein unfolding and exposure of hydrophobic residues, but also related to disruption of immunodominant linear epitopes (Glu177-Ser188 in tropomyosin, Gln361-Ser366 in β-actin) due to changes in gastrointestinal digestion behavior. Moreover, heat/digested stable epitopes of arginine kinase were located inside its 3D structure, preventing binding with IgE and maintaining hypoallergenicity following combined processing. Thus, steaming and reverse-pressure sterilization might be an efficient low-allergenic food processing method for Macrobrachium nipponense.