Nutriproteogenomic approach for detection and characterization of almond allergens
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2021-12-15
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Os frutos de casca rija são considerados um alimento importante numa dieta saudável. No entanto são uma das fontes mais comuns de alergénios alimentares responsáveis por reações alérgicas agudas que, em alguns casos, podem tornar-se mortais. Este grupo alimentar, pertence ao chamado “Big Eight Foods” que são responsáveis por mais de 90% dos casos de alergia alimentar nos Estados Unidos e neste grupo, as alergias à amêndoa e ao amendoim são persistentes e normalmente problemáticas. A amêndoa é geralmente consumida crua, tostada ou como parte de outros alimentos. O seu consumo está geralmente associado à redução do aparecimento de doenças cardiovasculares. Várias proteínas da amêndoa foram reconhecidas como alergénios. Seis deles, Pru du 3, Pru du 4, Pru du 5, Pru du 6, Pru du 8 e Pru du 10, foram incluídos na lista de alergénios da WHO-IUIS. Por outro lado, muitas proteínas de amêndoa já foram descritas como potenciais alergénios, embora apenas uma parte delas tenha sido reconhecida como alergénica e a autenticidade de algumas designações tenha sido questionada principalmente devido identificações erradas sendo, por isso necessário o desenvolvimento de linhas de investigação sobre a caracterização dos mesmos. Neste trabalho, o perfil proteico de 27 variedades de amêndoa, de quatro regiões diferentes da região de Trás-os-Montes, foi obtido através de eletroforese monodimensional. A ausência/presença de proteínas específicas foi utilizada para estabelecer relações de amostra através de dendrogramas. Além disso, o potencial alergénico destas variedades foi avaliado utilizando soro de 10 pacientes alérgicos como fonte de anticorpos IgE. Os resultados mostraram que diferentes variedades têm pequenas diferenças em relação ao seu perfil eletroforético, mas diferentes propriedades de ligação igE. Em particular, o soro de 5 pacientes apresentou um potencial alergénico com diferenças inter-varietais. A partir desses perfis surgiram resultados interessantes, como a identificação de possíveis reações aos putativos Pru du 8 e Pru du 10, apenas recentemente reconhecidos como alergénios da amêndoa e reação à putativa Pru du 1, uma proteína ainda não reconhecida como alergénio. A eletroforese bidimensional e o imunoblot adicional usando um conjunto dos soros de todos os indivíduos alérgicos usados neste estudo mostraram o complexo alergoma da amêndoa, com diferentes subunidades proteicas que possuem propriedades alergénicas. Finalmente, foi realizada uma breve caracterização genómica e Pru du 3 e Pru du 6 foram identificados em todas as variedades.
Tree nuts are widely considered an important food in a healthy diet. However, for a part of the world population, they are one of the most common sources of food allergens causing acute allergic reactions that, in some cases, can become life-threatening. They are part of the Big Eighth food groups which are responsible for more than 90% of food allergy cases in the United States and within this group, almond and peanut allergies are persistent and normally severe and life-threatening. Almond is generally consumed raw, toasted or as an integral part of other foods. Its dietary consumption is generally associated with a reduced risk of cardiovascular diseases. Several almond proteins have been recognized as allergens. Six of them, namely Pru du 3, Pru du 4, Pru du 5, Pru du 6, Pru du 8 and Pru du 10, have been included in WHO-IUIS list of allergens. On the other hand, a lot of almond proteins have been already described as potential allergens although only a part of them have been recognized as allergenic and the authenticity of some designations have been questioned mainly due to misidentification problems. Therefore, research about the accurate characterization of these allergens/proteins is needed. In this work, the protein profile of 27 almond varieties, from four different regions of the Trásos-Montes’s region, was obtained using 1D-eletrophoresis. The absence/presence of specific proteins was used to establish sample relationships trough dendrograms. Furthermore, the allergenic potential of these varieties was assessed using sera from 10 allergic patients as a source of IgE-antibodies. Results showed that different varieties have small differences regarding their electrophoretic profile, but different IgE-binding properties. In particular, the sera of 5 patients showed significant inter-varietal allergenic potential differences. Also, it was verified the IgE binding to the putatives Pru du 8 and Pru du 10, which were only recently recognized as almond allergens and most important to the putative Pru du 1, a protein not yet recognized as an almond allergen. Twodimensional electrophoresis and further immunoblotting using a pooled serum from all allergic individuals enrolled in the present study showed a complex almond allergome, with different protein subunits possessing allergenic properties. Finally, a brief genomic characterization was conducted and Pru du 3 and Pru du 6 were identified across all varieties.
Tree nuts are widely considered an important food in a healthy diet. However, for a part of the world population, they are one of the most common sources of food allergens causing acute allergic reactions that, in some cases, can become life-threatening. They are part of the Big Eighth food groups which are responsible for more than 90% of food allergy cases in the United States and within this group, almond and peanut allergies are persistent and normally severe and life-threatening. Almond is generally consumed raw, toasted or as an integral part of other foods. Its dietary consumption is generally associated with a reduced risk of cardiovascular diseases. Several almond proteins have been recognized as allergens. Six of them, namely Pru du 3, Pru du 4, Pru du 5, Pru du 6, Pru du 8 and Pru du 10, have been included in WHO-IUIS list of allergens. On the other hand, a lot of almond proteins have been already described as potential allergens although only a part of them have been recognized as allergenic and the authenticity of some designations have been questioned mainly due to misidentification problems. Therefore, research about the accurate characterization of these allergens/proteins is needed. In this work, the protein profile of 27 almond varieties, from four different regions of the Trásos-Montes’s region, was obtained using 1D-eletrophoresis. The absence/presence of specific proteins was used to establish sample relationships trough dendrograms. Furthermore, the allergenic potential of these varieties was assessed using sera from 10 allergic patients as a source of IgE-antibodies. Results showed that different varieties have small differences regarding their electrophoretic profile, but different IgE-binding properties. In particular, the sera of 5 patients showed significant inter-varietal allergenic potential differences. Also, it was verified the IgE binding to the putatives Pru du 8 and Pru du 10, which were only recently recognized as almond allergens and most important to the putative Pru du 1, a protein not yet recognized as an almond allergen. Twodimensional electrophoresis and further immunoblotting using a pooled serum from all allergic individuals enrolled in the present study showed a complex almond allergome, with different protein subunits possessing allergenic properties. Finally, a brief genomic characterization was conducted and Pru du 3 and Pru du 6 were identified across all varieties.
Descrição
Master in Comparative and Technological Molecular Genetics
Palavras-chave
alergia alimentar , amêndoa