Pine nut allergy is a global food safety concern, yet the epitope of the major allergen from Pinus yunnanensis Pin y 2 remains unknown. We identified linear B-cell epitopes of Pin y 2 using five bioinformatics tools, followed by indirect ELISA with rabbit anti-Pin y 2 IgG and sera from pine nut-allergic patients. Four IgE epitopes and three IgG epitopes were validated. All epitopes are surface-located and predominantly in negatively charged electrostatic regions. Alanine scanning revealed that leucine (L97, L98), glutamic acid (E419, E434, E436), and glutamine (Q442) are key residues, with their alanine substitution causing a reduction of more than 50% in IgE/IgG binding OD values. Comparative epitope mapping with other tree nut vicilin allergens showed the positional conservation but sequence divergence of the Pin y 2 epitope. These findings reveal the epitope map and epitope key residues of Pin y 2, which provides rational targets for hypoallergenic design and diagnostics.

Although pine nuts have gained increasing popularity, systematic studies of their allergens remain limited. Vicilin-like seed storage protein is an allergen in pine nuts. In this study, a 50 kDa protein from Pinus yunnanensis was purified and identified as a vicilin. Recombinant vicilin was expressed in Escherichia coli. Serological, spectroscopic, and bioinformatic methods were employed to evaluate its IgE/IgG-binding capacities, structural, and physicochemical characteristics. Results indicated that vicilin demonstrated potent IgE/IgG-binding capacities and was composed of 463 amino acids. Vicilin showed stability at 4-70 °C and pH 3-10, and no IgG cross-reactivity was observed with the tested species. P. yunnanensis vicilin was named Pin y 2 by the WHO/IUIS Allergen Nomenclature Sub-Committee. These findings provide a foundation for further investigation of vicilin and facilitate the development of specific detection and diagnostic approaches for pine nut allergy.

Fucoidan is a sulfated polysaccharide derived from brown algae (Saccharina japonica), and exhibits immunomodulatory properties. Emerging evidence suggests a strong correlation between the development of food allergy and intestinal dysfunction. The present study aimed to investigate the potential anti-food allergy activity of fucoidan and to elucidate its mechanism at the intestinal barrier function. The ovalbumin (OVA)-induced allergy mouse model was established, exhibiting increased OVA-specific IgE, histamine, Th2 inflammatory response, and intestinal damage. Oral administration of fucoidan markedly alleviated allergic symptoms by inhibiting mast cell activation and modulating intestinal immune responses. Furthermore, fucoidan significantly ameliorated intestinal immunological dysregulation, maintained barrier integrity, modulated gut microbiota composition, and enhanced short-chain fatty acid (SCFA) production. Mechanistically, the protective effects of fucoidan were closely associated with activation of the AMPK/SIRT1/FOXO1 pathway, which correlated with improved intestinal barrier function. Collectively, these results demonstrate that fucoidan may protect against food allergy by enhancing intestinal barrier function, highlighting the potential of natural biological substances in addressing food allergy.

ObjectiveTo investigate the status and challenges of allergen labeling on prepackaged snack foods in Qingdao City.MethodsTotally 1 095 samples were randomly collected across nine major snack food categories. Allergen label information was then statistically analyzed using SPSS.ResultsThe results showed an overall allergen labeling rate of 68.13% （746/1 095）， with only 23.74% （260/1 095） of products featuring preventive allergen labeling （PAL）. Notably， domestically produced foods exhibited a higher overall allergen labeling rate and a lower PAL rate than imported foods. Among the labeled products， 17.69% （132/746） included allergic foods beyond the “eight major categories”， while 14.61% （109/746） displayed allergen information in inconspicuous locations. Additionally， significant variability was observed in the presentation formats of allergen labels.ConclusionAlthough the allergen labeling rate for prepackaged snacks has improved considerably， the standardization of the allergen labeling remains inadequate， particularly for PAL， highlighting persistent regulatory shortcomings. To mitigate allergy risks and safeguard consumer health， standardizing allergen label formats， enhancing PAL-related regulations， and strengthening enforcement and oversight measures are recommended.

The increasing incidence of fish allergy, primarily triggered by parvalbumin (PV), has become a significant public health issue. Although novel PVs are increasingly being characterized, the allergenic epitopes have not been comprehensively identified. This study aimed to explore the IgE epitopes of PV and identify critical amino acid residues, while systematically assessing their connection to the IgE-binding capacity. PV from common fish species, which remains unstudied, was first characterized using proteomic, genomic, and immunoinformatic methods. β-PV isoforms from 92 fish species were comparatively analyzed with WEBLOGO and Clustal W, followed by epitope prediction with DNAStar Protean system, BepiPred 3.0, and IEDB. Validation was subsequently conducted with indirect competitive ELISA. Critical amino acid residues of epitopes were confirmed with the substitution approach. Sixteen linear B-cell epitopes of PV were identified, and four amino acids were confirmed as the crucial residues. Furthermore, the study revealed that allergenic peptides' distribution and specific residue arrangements govern IgE-binding potency.

Spotted seabass (Lateolabrax maculatus) is the second largest maricultural fish species in China and is the main trigger of food-related allergic reactions. Nevertheless, studies on the allergens of L. maculatus are limited. This study aimed to characterize pan-allergen parvalbumin from L. maculatus. Two proteins of about 11 kDa were purified and confirmed as parvalbumins by mass spectrometry. The IgG- and IgE-binding activities were evaluated through an immunoblotting assay. The molecular characteristics of β-parvalbumin were investigated by combining proteomics, genomics, and immunoinformatics approaches. The results indicated that β-parvalbumin consists of 109 amino acids with a molecular weight of 11.5 kDa and is the major allergen displaying strong IgE-binding capacity. In silico analysis and a dot blotting assay confirmed seven linear B cell epitopes distributed mainly on α-helixes and the calcium-binding loops. In addition, the cross-reactivity among 26 commonly consumed fish species was analyzed. The in-house generated anti-L. maculatus parvalbumin polyclonal antibody recognized 100% of the 26 fish species, demonstrating cross-reactivity and better binding capacity than the anticod parvalbumin antibody. Together, this study provides an efficient protocol to characterize allergens with multiomics methods and supports parvalbumin from L. maculatus as a candidate for fish allergen determination and allergy diagnosis.

A common epitope (AGSFDHKKFFKACGLSGKST) of parvalbumin from 16 fish species was excavated using bioinformatics tools combined with the characterization of fish parvalbumin binding profile of anti-single epitope antibody in this study. A competitive enzyme-linked immunosorbent assay (ELISA) based on the common epitope was established with a limit of detection of 10.15 ng/mL and a limit of quantification of 49.29 ng/mL. The developed ELISA exhibited a narrow range (71% to 107%) of related cross-reactivity of 15 fish parvalbumin. Besides, the recovery, the coefficient of variations for the intra-assay and the inter-assay were 84.3% to 108.2%, 7.4% to 13.9% and 8.5% to 15.6%. Our findings provide a novel idea for the development of a broad detection method for fish allergens and a practical tool for the detection of parvalbumin of economic fish species in food samples.

Download This Paper Open PDF in Browser Add Paper to My Library Share: Permalink Using these links will ensure access to this page indefinitely Copy URL Development of an Indirect Competitive Enzyme-Linked Immunosorbent Assay Based on the Common Epitope of Fish Parvalbumin for Fish Parvalbumin Detection 30 Pages Posted: 27 Feb 2024 See all articles by Yuhao HuangYuhao HuangOcean University of ChinaWenye ZhuOcean University of ChinaYeting WuOcean University of ChinaLirui SunQingdao UniversitySiddanakoppalu Narayana PramodDavangere UniversityHao WangOcean University of ChinaZiye ZhangOcean University of ChinaHong LiOcean University of ChinaZhenxing LiOcean University of China Abstract A common epitope (AGSFDHKKFFKACGLSGKST) of parvalbumin from 16 fish species was excavated using bioinformatics tools combined with the characterization of fish parvalbumin binding profile of anti-single epitope antibody in this study. A competitive enzyme-linked immunosorbent assay (ELISA) based on the common epitope was established with a limit of detection of 10.15 ng/mL and a limit of quantification of 49.29 ng/mL. The developed ELISA exhibited a narrow range (71% to 107%) of related cross-reactivity of 15 fish parvalbumin. Besides, the recovery, the coefficient of variations for the intra-assay and the inter-assay were 84.3% to 108.2%, 7.4% to 13.9% and 8.5% to 15.6%. Our findings provide a novel idea for the development of a broad detection method for fish allergens and a practical tool for the detection of parvalbumin of economic fish species in food samples. Keywords: Parvalbumin, Common epitope, ELISA, Related cross-reactivity Suggested Citation: Suggested Citation Huang, Yuhao and Zhu, Wenye and Wu, Yeting and Sun, Lirui and Pramod, Siddanakoppalu Narayana and Wang, Hao and Zhang, Ziye and Li, Hong and Li, Zhenxing, Development of an Indirect Competitive Enzyme-Linked Immunosorbent Assay Based on the Common Epitope of Fish Parvalbumin for Fish Parvalbumin Detection. Available at SSRN: https://ssrn.com/abstract=4733619 Yuhao Huang Ocean University of China ( email ) 5 Yushan RoadQingdao, 266003China Wenye Zhu Ocean University of China ( email ) 5 Yushan RoadQingdao, 266003China Yeting Wu Ocean University of China ( email ) 5 Yushan RoadQingdao, 266003China Lirui Sun Qingdao University ( email ) No. 308 Ning Xia RoadQingdao, 266071China Siddanakoppalu Narayana Pramod Davangere University ( email ) State Highway 76, TholahunaseDavangere, 577002India Hao Wang Ocean University of China ( email ) 5 Yushan RoadQingdao, 266003China Ziye Zhang Ocean University of China ( email ) 5 Yushan RoadQingdao, 266003China Hong Li Ocean University of China ( email ) 5 Yushan RoadQingdao, 266003China Zhenxing Li (Contact Author) Ocean University of China ( email ) Download This Paper Open PDF in Browser Do you have negative results from your research you’d like to share? Submit Negative Results Paper statistics Downloads 2 Abstract Views 12 39 References PlumX Metrics Feedback Feedback to SSRN Feedback (required) Email (required) Submit If you need immediate assistance, call 877-SSRNHelp (877 777 6435) in the United States, or +1 212 448 2500 outside of the United States, 8:30AM to 6:00PM U.S. Eastern, Monday - Friday.

Fucoidan is a native sulfated polysaccharide mainly isolated from brown seaweed, with diverse pharmacological activities, such as anti-inflammatory and antifibrosis. Hyperuricemia (HUA) is a common metabolic disease worldwide and mainly causes hyperuricemic nephropathy, including chronic kidney disease and end-stage renal fibrosis. The present study investigated the protective function of fucoidan in renal fibrosis and its pharmacological mechanism. The renal fibrotic model was established with the administration of potassium oxonate for 10 weeks. The protein levels of related factors were assessed in HUA mice by an enzyme-linked immunosorbent assay (ELISA) and western blotting. The results showed that fucoidan significantly reduced the levels of serum uric acid, blood urea nitrogen (BUN), α-smooth muscle actin (α-SMA), and collagen I, and improved kidney pathological changes. Furthermore, renal fibrosis had been remarkably elevated through the inhibition of the epithelial-to-mesenchymal transition (EMT) progression after fucoidan intervention, suppressing the Janus kinase 2 (JAK2) signal transducer and activator of transcription protein 3 (STAT3) signaling pathway activation. Together, this study provides experimental evidence that fucoidan may protect against hyperuricemia-induced renal fibrosis via downregulation of the JAK2/STAT3 signaling pathway.

The effect of linoleic acid (LA) on the IgG/IgE recognition, in vitro digestibility and immunodetection of shrimp tropomyosin (TM) was investigated. Subsequently, the simultaneous binding of LA-TM was explored using multi-spectroscopic and molecular modeling techniques. Our findings reveled that the addition of LA significantly reduced TM's IgG/IgE immunoreactivity, digestibility, and immunodetection. Further analysis using multi-spectroscopic and molecular modeling techniques indicated that while TM's secondary structure remained largely unchanged, its 3-D structure showed significant alterations such as increased particle size and hydrophobic surface area, and a higher number of buried hydrophobic residues exposed due to the binding of LA to TM. These structural changes rendered it difficult for target antibodies and digestive enzymes to interact with related epitopes and cleavage sites buried inside the molecule. The results obtained in this study provide valuable insights into the molecular mechanism of poor immunodetection caused by food matrix interference.

Fructose has been reported to acutely elevate the circulating fibroblast growth factor 21 (FGF21) levels, which ultimately causes FGF21 resistance. FGF21 resistance is suggested to result in lipid metabolism disorder. Nicotinamide riboside (NR) can alleviate lipid metabolism disorder in mice. It is unknown whether NR supplementation would alleviate lipid metabolism disorder in high-fructose exposed mice via improving FGF21 resistance. In this study, C57BL/6J mice were given 20% fructose solution for free drinking with the supplementation of NR in 400 mg kg-1 day-1. The results showed that NR supplementation decreased the serum and hepatic lipid profile levels. The increase of lipid droplets in the liver and the size of adipose cells in WAT induced by a high-fructose diet were alleviated by the addition of NR. NR supplementation increased the NAD+/NADH ratio and activated the SIRT1/NF-κB pathway. The down-regulation of NF-κB is accompanied by a decrease in inflammation, which may increase the expression of the FGF21 receptor complex, namely KLB and FGFR, then restore its downstream signaling cascade, including ERK phosphorylation and EGR1 and c-FOS expression, and ultimately improve FGF21 resistance. With the FGF21 function recovery, hepatic PGC-1α expression was up-regulated, and hepatic SREBP-1c expression was down-regulated, resulting in decreased lipogenesis. Furthermore, restoration of the FGF21 signaling pathway also led to increased expression of ATGL and HSL in WAT, which promotes lipolysis. In conclusion, we found that NR supplementation could ameliorate high-fructose-induced lipid metabolism disorder by improving FGF21 resistance in the liver and WAT, which may be related to the regulation of inflammation mediated by the SIRT1/NF-κB signaling pathway.

The gut–liver axis (GLA) plays an important role in the development of alcohol-induced liver injury. Alcohol consumption is typically associated with folic acid deficiency. However, no clear evidence has confirmed the effect of folic acid supplementation on alcohol-induced liver injury via GLA homeostasis. In this study, male C57BL/6J mice were given 56% (v/v) ethanol and 5.0 mg/kg folic acid daily by gavage for 10 weeks to investigate potential protective mechanisms of folic acid in alcohol-induced liver injury via GLA homeostasis. Histopathological and biochemical analyses showed that folic acid improved lipid deposition and inflammation in the liver caused by alcohol consumption and decreased the level of ALT, AST, TG, and LPS in serum. Folic acid inhibited the expression of the TLR4 signaling pathway and its downstream inflammatory mediators in the liver and upregulated the expression of ZO-1, claudin 1, and occludin in the intestine. But compared with the CON group, folic acid did not completely eliminate alcohol-induced intestine and liver injury. Furthermore, folic acid regulated alcohol-induced alterations in gut microbiota. In alcohol-exposed mice, the relative abundance of Bacteroidota was significantly increased, and the relative abundance of unclassified_Lachnospiraceae was significantly decreased. Folic acid supplementation significantly increased the relative abundance of Verrucomicrobia , Lachnospiraceae_NK4A136_group and Akkermansia , and decreased the relative abundance of Proteobacteria . The results of Spearman’s correlation analysis showed that serum parameters and hepatic inflammatory cytokines were significantly correlated with several bacteria, mainly including Bacteroidota , Firmicutes , and unclassified_Lachnospiraceae . In conclusion, folic acid could ameliorate alcohol-induced liver injury in mice via GLA homeostasis to some extent, providing a new idea and method for prevention of alcohol-induced liver injury.

Soybean allergens are commonly quantified using enzyme-linked immunosorbent assays (ELISAs) with anti-bodies produced by the single allergen. To enhance the specificity and avoid the false-negative results, the sandwich ELISA method was developed using a rabbit anti-bulk soybean proteins polyclonal antibody and a goat anti-bulk soybean proteins polyclonal antibody as the detection and capture antibody, respectively. The pro-posed method has been optimized and validated according to the requirements of the AOAC Allergen Com-munity. The method has a wide quantification range from 0.0625 mu g/mL to 6.0 mu g/mL and can quantify soybean residues at a low level down to 0.25 mg/kg with satisfactory accuracy (recovery range from 89.5% to 118%) and precision (RSDs < 16.67%). The new approach performs high specificity to soybean residues without obvious cross-reactivity to common allergic foods and legumes, and has been successfully applied to detect soybean proteins in commercial foods. Our data demonstrated that the established sandwich ELISA method has a higher specificity, accuracy, and robustness that could meet the quantification requirements for soybean allergens.

Accumulating evidence points to a critical role of the brain gut axis as an important paradigm for many central nervous system diseases. Recent studies suggest that propolis has obvious neuroprotective properties and functionality in regulating intestinal bacteria flora, hinting at a potential key effect at both terminals of this axis regulation. However, currently no clear evidence confirms the effects of propolis on alcohol-induced depression. Here, we establish an alcoholic depression model with C57BL/6J mice and demonstrate that treatment with propolis protects against alcohol-induced depressive symptoms by behavioral tests. In addition, propolis attenuates the injury of nerve cells in the hippocampal region and restores the serum levels of brain-derived neurotrophic factor (BDNF) and dopamine (DA) in mice with alcohol-induced depression. Pathology and biotin tracer assays show that propolis repairs the intestinal leakage caused by alcohol. Additionally, propolis treatment increases the expression levels of intestinal intercellular tight junctions' (TJs') structural proteins Claudin-1, Occludin and zona occludens-1 (ZO-1), as well as the activation state of the liver kinase B1/AMP-activated protein kinase (LKB1/AMPK) signaling pathway, which is closely related to the intestinal permeability. Furthermore, propolis can reduce the levels of pro-inflammatory, lipopolysaccharide (LPS) and fatty-acid-binding protein 2 (FABP2), suggesting the significance of the inflammatory response in alcoholic depression. Collectively, our findings indicate that propolis exerted an improving effect on alcohol-induced depressive symptoms by ameliorating brain gut dysfunction.

BACKGROUND: Allergic reactions to crustacean products have been increasing owing to the rising consumption. Tropomyosin (TM) is the main crustacean allergen; it has a coiled-coil structure, which shows stability to various food processing methods. Crustacean processed products have been used in several food products, thereby causing greater difficulties in detecting TM in these products. We aimed to develop an assay based on high-performance liquid chromatography-tandem mass spectrometry for the accurate and reproducible quantification of crustacean TM in foods. RESULTS: The three peptides IQLLEEDLER, LAEASQAADESER, and IVELEEELR were selected as peptide markers, and the peptide IVELEEELR was selected as the quantitative marker. Extraction conditions and enzymatic digestion conditions were completely optimized. The extraction solution of Tris-hydrochloric acid buffer (50 mmol L-1, pH 7.4) containing 1 mol L-1 potassium chloride and the enzymatic treatment at 1:15 ratio (enzyme/protein, m/m) for 13 h showed excellent efficiency. The method exhibited a good linear relationship, with the qualified coefficient of determination (R-2 = 0.9994) in the wide range of 1 to 1000 mu g L-1. The accuracy was validated based on spiked recovery at three spiking levels (12.5, 25.0, and 50.0 mu g kg(-1), TM/matrix) in blank matrices that included chicken sausages, beef balls, and egg-milk biscuits. The recoveries ranged from 91% to 109% with qualified relative standard deviations <15% with the limit of quantification (of 1.6 mg kg(-1), TM/matrix). CONCLUSION: This new approach can be used for the qualitative and quantitative detection of crustacean TM in various food matrices. (C) 2021 Society of Chemical Industry.

In this study, the effect of enzymatic cross-linking of shrimp tropomyosin (TM) with tyrosinase and caffeic acid (TM-Tyr/CA) on the allergic response were assessed using in vitro and in vivo models. The RBL-2H3 and KU812 cell lines were employed to evaluate the changes in the stimulation abilities of TM-Tyr/CA that showed significant inhibition of mediators and cytokines. The digestibility of cross-linked TM was improved and the recognitions of IgG/IgE were markedly reduced, as revealed by western blotting. TM-Tyr/CA decreased anaphylactic symptoms, and hindered the levels of IgG1, IgE, histamine, tryptase and mouse mast-cell protease-1 (mMCP-1) in mice sera. Cross-linked TM downregulated the production of interleukin (IL)-4, IL-5, and IL-13 by 51.36, 12.24 and 20.55%, respectively, whereas, IL-10 and IFN-γ were upregulated by 20.71 and 19.0%. TM-Tyr/CA showed reduced allergenicity and may have preventive effect in relieving TM induced allergic response via immunosuppression and positive modulation of T-helper (Th)1/Th2 immunobalance.

BACKGROUND Allergic reactions to crustacean products have been increased owing to the rising consumption. Tropomyosin (TM) is the main crustacean allergen with a coiled-coil structure, which showed stability to various food processing methods. Crustacean processed products have been used in several food products, thereby causing greater difficulties in detecting TM in these products. We aimed to develop an assay based on High-Performance Liquid Chromatography-Tandem Mass Spectrometry (HPLC-MS/MS) for the accurate and reproducible quantification of crustacean TM in foods. RESULTS Three peptides of IQLLEEDLER, LAEASQAADESER, and IVELEEELR were selected as peptide markers, and the peptide of IVELEEELR was selected as the quantitative marker. Extraction conditions and enzymatic digestion conditions were completely optimized. The extraction solution of Tri-HCl buffer (50 mM, pH=7.4) containing 1 mol·L-1 KCl and the enzymatic treatment at 1:15 ratio (enzyme/protein, m/m) for 13 h showed excellent efficiency. The method exhibited a good linear relationship with the qualified coefficient of determination (R2 =0.9994) in the wide range of 1 to 1000 μg·L-1 . The accuracy was validated based on spiked recovery at three spiking levels (12.5, 25.0, and 50.0 μg·kg-1 , TM/matrix) in the blank matrices including chicken sausages, beef balls, and egg-milk biscuits. The recoveries ranged from 91% to 109% with qualified relative standard deviations (RSDs) < 15% with the limit of quantification (LOQ) of 1.6 mg·kg-1 (TM/matrix). CONCLUSION The new approach can be used for the qualitative and quantitative detection of crustacean TM in various food matrices. This article is protected by copyright. All rights reserved.

In the present study, the influence of lipid emulsion on the allergenicity of digestion products of fish parvalbumin (PV) was investigated, which was initially subjected to simulated gastric/intestinal digestion both under emulsified and non-emulsified conditions. The release of β-hexosaminidase (β-hex), histamine (His), tryptase (TPS), interleukin 4 (IL-4), and IL-13 in RBL cells was decreased by 79.32, 26.19, 41.67, 53.95 and 54.40%, respectively, following stimulation with the gastric digestion products of PV. Whereas, lipid emulsified digestion products of PV (e-PV) significantly enhanced the release of active mediators and cytokines. The digestion products of emulsified PV at 180 min resulted in a higher release of β-hex (197.60%), His (12.18%), TPS (38.85%), IL-4 (48.19%) and IL-13 (59.40%), as compared to that of PV. However, no obvious differences in the release of active substances and cytokines were noted between intestinal digestion products of PV and intestinal digestion products of emulsified PV. In the mouse model studies, digested PV products reduced the anaphylactic scores, whereas e-PV manifested a higher level of allergic symptoms. Moreover, mice treated with 50% e-PV had significantly higher levels of specific IgE (32.56%), total IgE (16.67%) and total IgG1 (5.15%) than those treated with 50% PV. Mice treated with 50% e-PV had significantly higher levels of His (8.50%) and TPS (10.07%) compared with mice treated with 50% PV. Lipid emulsions altered the digestibility of PV in gastrointestinal digestion and enhanced the allergenicity of PV digestion products at the cellular levels, subsequently posing a higher risk of allergic reactions in susceptible individuals.

Tropomyosin (TM) is a highly conserved protein that considered as the major allergen of crustacean and mollusk species, while, fish-TM also shares high homology with low allergenicity. In this study, the amino acid sequence, B cell epitopes and allergenicity of shrimp (Litopenaeus vannamei), which is widely consumed, were evaluated by using immunoinformatic tools, dot-blot, enzyme-linked immunosorbent assay (ELISA) and mediator release assay. Meanwhile, cross-reactivity of allergic epitopes of fish-TM, shrimp-TM and clam-TM were assessed. Results showed that three IgE-binding epitopes (X1: 47-61, QKRMQQLENDLDQVQ; X2: 97-108, EDLERSEERLNT and X3: 244-257, RSVQKLQKEVDRLE) of shrimp-TM also exhibited degranulation ability. In comparison with epitopes from shrimp-TM, those from clam-TM showed high cross-reactivity (>80%) and degranulation ability, while those from fish-TM showed low cross-reactivity (<20%). These findings would apply a new understanding of the cross-reactivity of TM from fish, shrimp and clam in terms of allergenic epitopes.

Tropomyosin (TM), acting as heat-stable protein, has a high homology of amino acid sequences with different sensitizations. Fish belongs to vertebrate and its TM owns less allergenicity, whereas shrimp and clam belong to invertebrate and their TM are major allergens. Moreover, the allergenicity of TM might be altered during food processing. Therefore, shrimp-TM was administered intraperitoneally to BALB/c mice to establish an allergic mouse model, to evaluate the elicitation ability of these three proteins, while a mediator-releasing RBL cell line was used to estimate the variation in the stimulation abilities. The results showed that shrimp-TM owned stronger ability in the elicitation of the anaphylactic reactivity as well as in the IgE-mediated the RBL cell line. In comparison with shrimp-TM, clam-TM showed a similar allergic reaction and T-helper 2 (Th2)-based responses from spleen cells and mediums produced by RBL cell line, while fish-TM exhibited a weaker anaphylactic reactivity based on a mouse model and produced fewer active mediums based on cell model. Furthermore, raw and boiled TM did not exhibit a significant difference in allergic reactions and the capacity of degranulation. These results indicated that shrimp-TM owned stronger stimulation ability based on allergic mouse compared with fish-TM and clam-TM, which could supply information for clinical and anaphylaxis of TM in the stages of sensitization and simulation deserve further consideration.