Digestibility And Potential Allergenicity Of Gluten Proteins In Seventeen Wheat Varieties

Gluten proteins are a common antigen for both celiac disease and IgE mediated wheat allergy.Celiac disease is an autoimmune disease caused by an abnormal reaction of intestinal T cells to gluten proteins,and recognition of gluten proteins epitopes by CD4~+T cells is thought to be the key to triggering celiac disease.IgE-mediated wheat allergy can be defined as hypersensitivity to wheat proteins.Th2cells are involved in wheat allergy and are the key to the production of IgE antibodies by B cells.Wheat allergen epitopes bind to IgE antibodies on the surface of mast cells or basophil cells,cross-linking the IgE receptors and activating the cells to release bioactive mediators,resulting in local or systemic allergic reactions.The adherence to a gluten-free diet is currently the only available therapy for CD.The only available therapy for IgE-mediated wheat allergy is strict avoidance of wheat.There were significant differences in the composition and number of antigenic epitopes in different wheat varieties,which can be quantitatively analyzed by immunological techniques.Based on this,wheat varieties with low celiac disease toxicity or hypoallergenicity can be screened out,providing safe wheat varieties resources for the research and development of wheat products with low celiac disease toxicity or hypoallergenicity.In addition,gluten proteins are resistant to gastrointestinal digestion due to its high content of proline and glutamine,and the digestive product polypeptides still have the antigenic characteristics of gluten proteins.Therefore,the assessment of the digestibility of gluten proteins has research value.The main methods,results and conclusions of this study are as follows:1.In this study,nine Xinjiang wheat varieties and eight Chengdu wheat varieties were selected to extract gluten proteins from varieties,and the celiac disease Glia-α9 and Glia-α20 epitope contents of gluten proteins in the seventeen kinds of wheat was assessed by western blot.In the tested Xinjiang wheat varieties,two wheat varieties with high celiac disease toxicity were screened out,namely Xinshuguang.1 and 04-Yinjian 105;Two wheat varieties with low celiac disease toxicity were screened out,namely Xinchun 20 and Achun.2;Tuchun.6 was a moderately toxic wheat variety.In the tested Chengdu wheat varieties,the celiac disease Glia-α9 and Glia-α20 epitope contents of gluten proteins in eight kinds of Chengdu wheat from high to low were W9,W24,W6,W5,W15,W4,W1,W25.2.Using the serum of wheat allergy sufferers as primary antibody,the allergenicity of Xinjiang wheat varieties with high,medium and low celiac disease toxicity and eight Chengdu wheat varieties were assessed by western blot.Three wheat varieties with high,medium and low allergenicity were screened out,which were Chengdu wheat W1,Xinjiang wheat Xinchun 20 and Chengdu wheat W24.Some Xinjiang wheat varieties and Chengdu wheat varieties showed consistent results in celiac disease toxicity and allergenicity.3.Xinjiang wheat Xinchun 20 and Achun.2 could be used as candidate seeds for low celiac disease toxicity.Chengdu wheat W1 could be a candidate seed for hypoallergenicity.4.INFOGEST,a standardized method that simulates food digestion in vitro,was used to simulate the digestion of wheat gluten proteins in adult and infant gastrointestinal fluids.It was found that gluten proteins of the three representative test wheat varieties were more stable in simulated infant digestive fluids than in adult digestive fluids.The digested gluten proteins had strong potential allergenicity,and the allergenicity of infant digestive products was stronger,suggesting that gluten proteins were more likely to cause allergy in infants.