Presence of celiac disease epitopes in modern and old hexaploid wheat varieties: wheat breeding may have contributed to increased prevalence of celiac disease

Abstract

Gluten proteins from wheat can induce celiac disease (CD) in genetically susceptible individuals. Specific gluten peptides can be presented by antigen presenting cells to gluten-sensitive T-cell lymphocytes leading to CD. During the last decades, a significant increase has been observed in the prevalence of CD. This may partly be attributed to an increase in awareness and to improved diagnostic techniques, but increased wheat and gluten consumption is also considered a major cause. To analyze whether wheat breeding contributed to the increase of the prevalence of CD, we have compared the genetic diversity of gluten proteins for the presence of two CD epitopes (Glia-α9 and Glia-α20) in 36 modern European wheat varieties and in 50 landraces representing the wheat varieties grown up to around a century ago. Glia-α9 is a major (immunodominant) epitope that is recognized by the majority of CD patients. The minor Glia-α20 was included as a technical reference. Overall, the presence of the Glia-α9 epitope was higher in the modern varieties, whereas the presence of the Glia-α20 epitope was lower, as compared to the landraces. This suggests that modern wheat breeding practices may have led to an increased exposure to CD epitopes. On the other hand, some modern varieties and landraces have been identified that have relatively low contents of both epitopes. Such selected lines may serve as a start to breed wheat for the introduction of 'low CD toxic' as a new breeding trait. Large-scale culture and consumption of such varieties would considerably aid in decreasing the prevalence of CD.

Fig. 1

Analyses of gluten protein extracts from 36 modern wheat varieties and hexaploid landrace accessions. Immunoblots modern varieties using a mAb Glia-α9, b mAb Glia-α20. Immunoblots landraces using c mAb Glia-α9, d mAb Glia-α20. Boxes indicate ‘block-1’ and ‘block-2’ proteins

Fig. 2

Images represent immunoblot results for modern wheat varieties Bovictus, Combi, Zentos, Glockner, Toronto, Tambor, Winni, and Bold. a Red channel shows the results with mAb Glia-α9. b Green channel for results with mAb Glia-α20. c Overlay of both images in (a) and (b). In yellow, identical gluten protein bands are shown

Fig. 3

2-DE analysis of the gluten protein extracts from modern wheat varieties Bovictus and Sperber. a 2-DE gel of ‘Bovictus’ stained with PageBlue. b Immunoblot of ‘Bovictus’ using mAb Glia-α9. c Immunoblot of ‘Bovictus’ using mAb Glia-α20. d Immunoblot of ‘Sperber’ using mAb Glia-α20. Lanes at the left in (b), (c), and (d) are one-dimensional immunoblots. Boxes indicate ‘block-1’ and ‘block-2’ proteins

Fig. 4

Immunoblots from Fig. 1 were scanned and the relative intensities are shown for mAbs Glia-α9 and Glia-α20. a Glia-α9 in modern wheat varieties, b Glia-α20 in modern wheat varieties, c Glia-α9 in wheat landraces, and d Glia-α20 in wheat landraces