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Pomés A, Smith SA, Chruszcz M, Mueller GA, Brackett NF, Chapman MD. Precision engineering for localization, validation, and modification of allergenic epitopes. J Allergy Clin Immunol 2024; 153:560-571. [PMID: 38181840 PMCID: PMC10939758 DOI: 10.1016/j.jaci.2023.12.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 12/20/2023] [Accepted: 12/29/2023] [Indexed: 01/07/2024]
Abstract
The allergen-IgE interaction is essential for the genesis of allergic responses, yet investigation of the molecular basis of these interactions is in its infancy. Precision engineering has unveiled the molecular features of allergen-antibody interactions at the atomic level. High-resolution technologies, including x-ray crystallography, nuclear magnetic resonance spectroscopy, and cryo-electron microscopy, determine allergen-antibody structures. X-ray crystallography of an allergen-antibody complex localizes in detail amino acid residues and interactions that define the epitope-paratope interface. Multiple structures involving murine IgG mAbs have recently been resolved. The number of amino acids forming the epitope broadly correlates with the epitope area. The production of human IgE mAbs from B cells of allergic subjects is an exciting recent development that has for the first time enabled an actual IgE epitope to be defined. The biologic activity of defined IgE epitopes can be validated in vivo in animal models or by measuring mediator release from engineered basophilic cell lines. Finally, gene-editing approaches using the Clustered Regularly Interspaced Short Palindromic Repeats technology to either remove allergen genes or make targeted epitope engineering at the source are on the horizon. This review presents an overview of the identification and validation of allergenic epitopes by precision engineering.
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Affiliation(s)
| | - Scott A Smith
- Vanderbilt University Medical Center, Nashville, Tenn
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Hon KL, Tan YW, Leung KKY, Fung GPG, Li PH. Emergency Management of Food-induced Anaphylaxis and Severe Reactions in Young Infants. Curr Pediatr Rev 2024; 20:111-114. [PMID: 36305133 DOI: 10.2174/1573396319666221027115126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 08/15/2022] [Accepted: 08/15/2022] [Indexed: 11/22/2022]
Affiliation(s)
- Kam Lun Hon
- Department of Paediatrics and Adolescent Medicine, Hong Kong Children's Hospital, Hong Kong, China
- Department of Paediatrics, Chinese University of Hong Kong, China
| | - Yok Weng Tan
- Department of Paediatrics and Adolescent Medicine, Hong Kong Children's Hospital, Hong Kong, China
| | - Karen Ka Yan Leung
- Department of Paediatrics and Adolescent Medicine, Hong Kong Children's Hospital, Hong Kong, China
| | - Genevieve P G Fung
- Department of Paediatrics, Chinese University of Hong Kong, Hong Kong, China
| | - Philip Hei Li
- Department of Medicine, School of Clinical Medicine at The University of Hong Kong, Hong Kong, China
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Sun N, Liu Y, Liu K, Wang S, Liu Q, Lin S. Gastrointestinal fate of food allergens and its relationship with allergenicity. Compr Rev Food Sci Food Saf 2022; 21:3376-3404. [PMID: 35751399 DOI: 10.1111/1541-4337.12989] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 03/29/2022] [Accepted: 05/09/2022] [Indexed: 01/15/2023]
Abstract
Food allergens are closely related to their gastrointestinal digestion fate, but the changes in food allergens during digestion and related mechanisms are quite complicated. This review presents in detail digestion models for predicting allergenicity, the fates of food allergens in oral, gastric and duodenal digestion, and the applications of digestomics in mapping IgE-binding epitopes of digestion-resistant peptides. Moreover, this review highlights the structure-activity relationships of food allergens during gastrointestinal digestion. Digestion-labile allergens may share common structural characteristics, such as high flexibility, rendering them easier to be hydrolyzed into small fragments with decreased or eliminated allergenicity. In contrast, the presence of disulfide bonds, tightly wound α-helical structures, or hydrophobic domains in food allergens helps them resist gastrointestinal digestion, stabilizing IgE-binding epitopes, thus maintaining their sensitization. In rare cases, digestion leads to increased allergenicity due to exposure of new epitopes. Finally, the action of the food matrix and processing on the digestion and allergenicity of food allergens as well as the underlying mechanisms was overviewed. The food matrix can directly act on the allergen by forming complexes or new epitopes to affect its gastrointestinal digestibility and thereby alter its allergenicity or indirectly affect the allergenicity by competing for enzymatic cleavage or influencing gastrointestinal pH and microbial flora. Several processing techniques attenuate the allergenicity of food proteins by altering their conformation to improve susceptibility to degradation by digestive enzymes. Given the complexity of food components, the food itself rather than a single allergen should be used to obtain more accurate data for allergenicity assessment. PRACTICAL APPLICATION: The review article will help to understand the relationship between food protein digestion and allergenicity, and may provide fundamental information for evaluating and reducing the allergenicity of food proteins.
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Affiliation(s)
- Na Sun
- School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian, P. R. China.,Collaborative Innovation Center of Seafood Deep Processing, Dalian Polytechnic University, Dalian, P. R. China
| | - Yao Liu
- School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian, P. R. China
| | - Kexin Liu
- School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian, P. R. China
| | - Shan Wang
- School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian, P. R. China
| | - Qiaozhen Liu
- School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian, P. R. China.,Collaborative Innovation Center of Seafood Deep Processing, Dalian Polytechnic University, Dalian, P. R. China
| | - Songyi Lin
- School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian, P. R. China.,Collaborative Innovation Center of Seafood Deep Processing, Dalian Polytechnic University, Dalian, P. R. China
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LTP Allergy Follow-Up Study: Development of Allergy to New Plant Foods 10 Years Later. Nutrients 2021; 13:nu13072165. [PMID: 34202484 PMCID: PMC8308245 DOI: 10.3390/nu13072165] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 06/16/2021] [Accepted: 06/22/2021] [Indexed: 01/27/2023] Open
Abstract
Introduction: Allergy to nonspecific lipid transfer protein (nsLTP) is the main cause of plant-food allergy in Spain. nsLTPs are widely distributed in the plant kingdom and have high cross-reactivity but extremely variable clinical expression. Little is known about the natural evolution of this allergy, which complicates management. The objective of this study was to assess the development of allergy to new plant foods in nsLTP-sensitized patients 10 years after diagnosis. Methods: One hundred fifty-one patients showing specific IgE to nsLTP determined by ISAC (Thermofisher) were included. After clinical workup (i.e., anamnesis, skin test, and challenge when needed), these patients were divided into two groups: 113 patients allergic to one or more plant food (74.5%) and 38 patients not allergic to any plant food (25.1%). Ten years later, a telephone interview was conducted to check whether patients had developed additional allergic reactions to plant foods. Results: Ten years after diagnosis, 35 of the 113 (31%) plant-food-allergic patients sensitized to nsLTP reported reactions to new, previously tolerated plant foods, mainly Rosaceae/Prunoideae fruits and nuts followed by vegetables, Rosacea/Pomoideae fruits, legumes, and cereals. Five out of 38 (13.2%) patients previously sensitized to nsLTP but without allergy to any plant food had experienced allergic reactions to some plant food: two to Rosaceae/Prunoideae fruits, two to Rosaceae/Prunoideae fruit and nuts, and one to legumes. Conclusion: Patients sensitized to nsLTP developed allergic reactions to other plant foods, mainly Rosaceae-Prunoideae fruits and nuts. This was more frequent among plant-food-allergic patients than among those who had never had plant-food allergy.
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Wang XM, Tu ZC, Ye YH, Liu GX, Wang H, Hu YM. Mechanism on the Allergenicity Changes of α-Lactalbumin Treated by Sonication-Assisted Glycation during In Vitro Gastroduodenal Digestion. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:6850-6859. [PMID: 34114451 DOI: 10.1021/acs.jafc.1c02205] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Physical-assisted chemical modification is effective to reduce the allergenicity of α-lactalbumin (ALA). However, there are few in-depth studies on the allergenicity changes of physical-assisted chemical-modified ALA during digestion. The effect of gastroduodenal digestion on the allergenicity changes of ALA treated by sonication-assisted glycation was assessed. Digestion of both ALA and its glycated forms generated peptide fractions, and intact undigested glycated ALA in the hydrolysates still covalently bound to d-galactose. High-resolution mass spectrometry revealed that a higher glycation degree was discovered in sonication-preprocessed ALA compared to native ALA. Enzyme-linked immunosorbent assay and basophil degranulation showed that sonication-assisted glycation could significantly reduce ALA allergenicity. The allergenicity of both gastric and gastroduodenal hydrolysates was further increased, and the hydrolysates of sonication-assisted glycated ALA showed the lowest allergenicity. The reason could be the shielding effect of the linear epitope found to be caused by a higher glycation degree; although linear epitopes were exposed, d-galactose covalently bound to intact undigested glycated ALA in the hydrolysates retained its masking role. These results indicated that sonication-assisted glycation could be a promising method to prepare immunotherapeutic agents for allergen immunotherapy to achieve the purpose of allergy desensitization.
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Affiliation(s)
- Xu-Mei Wang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, Jiangxi 330047, People's Republic of China
| | - Zong-Cai Tu
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, Jiangxi 330047, People's Republic of China
- National R&D Branch Center for Conventional Freshwater Fish Processing, Jiangxi Normal University, Nanchang, Jiangxi 330022, People's Republic of China
- Engineering Research Center of Freshwater Fish High-Value Utilization of Jiangxi Province, Jiangxi Normal University, Nanchang, Jiangxi 330022, People's Republic of China
| | - Yun-Hua Ye
- National R&D Branch Center for Conventional Freshwater Fish Processing, Jiangxi Normal University, Nanchang, Jiangxi 330022, People's Republic of China
- Engineering Research Center of Freshwater Fish High-Value Utilization of Jiangxi Province, Jiangxi Normal University, Nanchang, Jiangxi 330022, People's Republic of China
| | - Guang-Xian Liu
- Institute of Food Science and Technology, Jiangxi Academy of Agricultural Sciences, Nanchang, Jiangxi 330200, People's Republic of China
| | - Hui Wang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, Jiangxi 330047, People's Republic of China
| | - Yue-Ming Hu
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, Jiangxi 330047, People's Republic of China
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