Proteomic and Bioinformatic Investigations of Heat-Treated Anisakis simplex Third-Stage Larvae.

Maciej Kochanowski,Tomasz Cencek,Mirosław Różycki,Aneta Bełcik,Jacek Sroka,Joanna Dąbrowska,Jacek Karamon

doi:10.3390/biom10071066

Maciej Kochanowski, Tomasz Cencek + Show 5 more

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https://doi.org/10.3390/biom10071066

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Journal: Biomolecules	Publication Date: Jul 16, 2020
Citations: 8	License type: CC BY 4.0

Affiliation: National Veterinary Research Institute

Abstract

Anisakis simplex third-stage larvae are the main source of hidden allergens in marine fish products. Some Anisakis allergens are thermostable and, even highly processed, could cause hypersensitivity reactions. However, Anisakis proteome has not been studied under autoclaving conditions of 121 °C for 60 min, which is an important process in the food industry. The aim of the study was the identification and characterization of allergens, potential allergens, and other proteins of heat-treated A. simplex larvae. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to identify 470 proteins, including allergens—Ani s 1, Ani s 2, Ani s 3, Ani s 4, Ani s 5—and 13 potential allergens that were mainly homologs of Anisakis spp., Ascaris spp., and Acari allergens. Ani s 2, Ani s 3, Ani s 5, and three possible allergens were found among the top 25 most abundant proteins. The computational analysis allowed us to detect allergen epitopes, assign protein families, and domains as well as to annotate the localization of proteins. The predicted 3D models of proteins revealed similarities between potential allergens and homologous allergens. Despite the partial degradation of heated A. simplex antigens, their immunoreactivity with anti-A. simplex IgG antibodies was confirmed using a Western blot. In conclusion, identified epitopes of allergenic peptides highlighted that the occurrence of Anisakis proteins in thermally processed fish products could be a potential allergic hazard. Further studies are necessary to confirm the IgE immunoreactivity and thermostability of identified proteins.

Highlights

Foodborne parasites are one of the most important causative agents of human infectious diseases, especially in less developed countries [1,2]
Based on mass spectrometry analysis, it could be concluded that 470 proteins were detected in heat-treated A. simplex larvae
In silico predicted and known epitopes in peptides originated from these allergens were detected using bioinformatics tools

Summary

Introduction

Foodborne parasites are one of the most important causative agents of human infectious diseases, especially in less developed countries [1,2]. Foodborne parasites remain neglected compared with bacterial and viral pathogens [3] Studies in this field, like epidemiological surveys [5,6], development of novel diagnostic tools [7,8,9], drug discovery [10], or investigation of pathogenicity [11], are valuable. Due to very nonspecific symptoms of the disease, the number of detected cases is considered to be highly underestimated [16]. These assumptions confirm the results of the last study in which the number of anisakiasis cases requiring medical attention in Spain has been estimated at around 8000 per year [17]

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