Studies in vivo of ω-gliadins in gluten sensitivity (coeliac sprue disease)

Ensarı, Arzu; Marsh, Michael N.; Moriarty, Kieran; Moore, Carol. M.; Fido, Roger J.; Tatham, Arthur S.

doi:10.1042/cs0950419

Cited by 28 publications

(13 citation statements)

References 36 publications

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“…In this article, we present information about the structure of one group of dough constituents, the sulfur-poor ω-gliadins. The repetitive structure of gluten subunits may play an important role in the unique viscoelastic properties of the gluten protein complexes, although evidence for this is lacking, as well as having a role in the immunogenic activity of these proteins (Ensari et al 1999). Our data support the idea that the somewhat flexible but extended ω-gliadin molecules interact cohesively with other dough proteins.…”

Section: Discussionsupporting

confidence: 64%

Characterization of the 1B‐Type ω‐Gliadins from Triticum aestivum Cultivar Butte

et al. 2000

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Cereal Chem. 77(5):607-614 ω-Gliadins were purified from wheat (Triticum aestivum L. 'Butte') flour and characterized. Although reversed-phase HPLC (RP-HPLC) separated the 1B-encoded ω-gliadins into two fractions, 1B1 and 1B2, these fractions had nearly identical amino acid compositions, three similar protein bands in SDS-PAGE, 10 similar spots in two-dimensional PAGE, and two similar N-terminal amino acid sequences. The main components had a range in mass of 48,900-51,500 when estimated by mass spectrometry, significantly less than the mass estimated by SDS-PAGE. The 1B fractions were digested with thermolysin, the peptides were separated by RP-HPLC, the peptide mass was determined, and nine peptides from each fraction were sequenced with nearly identical results for the 1B1 and 1B2 digests. A possible consensus sequence of the 1B-encoded ω-gliadin internal repeat was QQQXP, where X was F, I, or L in descending order of occurrence. The 1D-encoded ω-gliadins were purified by RP-HPLC as a single fraction that had one band in SDS-PAGE, two spots in two-dimensional PAGE, two components with mass of 41,923 and 42,770 detected by mass spectrometry, and two N-terminal sequences. Circular dichroism (CD) spectra for the 1B and 1D ω-gliadins were similar and were suggestive of mainly flexible random structure with a significant amount of the left-handed polyproline II helical conformation in the 1D components.The ω-gliadin components of wheat flour are sulfur-poor prolamins with no cysteine. Closely related components that contain cysteine are referred to as D-glutenin subunits (Masci et al 1998).The ω-gliadins are composed almost entirely of high-glutamine, high-proline repeats and are related to the rye ω-secalins and the barley C-hordeins (Tatham and Shewry 1995). Several distinct ω-gliadins were identified in wheat based on electrophoretic patterns and N-terminal sequences, and their genes were localized to the Gli-B1 and Gli-D1 loci on the short arms of chromosome 1B and 1D, respectively (Kasarda et al 1983, Lafiandra et al 1984, Tatham and Shewry 1995, Zhao et al 1999. Additional ω-gliadin-like proteins, with genes located at the Gli-A1 locus on the short arm of chromosome 1A are less well characterized. Wheat was estimated to have at least 15-18 copies of ω-gliadin genes (Sabelli and Shewry 1991). In this article, we refer to the Gli-A1, Gli-B1, and Gli-D1 encoded ω-gliadins as the 1A, 1B, and 1D ω-gliadins.Sulfur availability and the ratio of sulfur to nitrogen in the soil affect dough elasticity and resistance and loaf volume, probably because of the effect of sulfur-to-nitrogen ratios on the gluten protein composition of wheat flour (Zhao et al 1999). The relative abundance of the sulfur-poor prolamins, particularly the ω-gliadins, and the intermediate-sulfur high molecular weight glutenin subunits (HMW-GS), increased when wheat plants were depleted of sulfur (Wrigley et al 1984, Zhao et al 1999 but the significance of changes in ω-gliadin amounts to dough quality is unknown. Because the ω-gliadins have no cyste...

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Section: Discussionsupporting

confidence: 64%

Characterization of the 1B‐Type ω‐Gliadins from Triticum aestivum Cultivar Butte

et al. 2000

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“…In the case of the ω‐gliadins, the fragments resulting from digestion may be expected to be larger than those of the other classes because of the greater amounts of proline in the primary structures of the two subtypes of ω‐gliadins (1D‐coded and 1B‐coded). Several reports indicate activity for ω‐gliadins in celiac disease (9, 60, 62).…”

Section: What Is So Special About Gluten That Challenges Our Immune Smentioning

confidence: 99%

Innate and adaptive immunity: the Yin and Yang of celiac disease

Jabrì

Kasarda

Green

2005

Immunological Reviews

112

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“…Loft et al (23) suggested that this might make a useful screening test for untreated CD. Ensari and colleagues (24) used this technique to confirm the toxicity of highly purified omegagliadin fractions. More recently, it was shown that oral submucosal injection of gluten in celiac patients led to a significant rise in lamina propria lymphocytes (25).…”

Section: Toxicity Testing Of Prolaminsmentioning

confidence: 99%

In vivo gluten challenge in coeliac disease

Ellis

Ciclitira

2001

Canadian Journal of Gastroenterology

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In vivo gluten challenge has been used since the early 1950s to study the role of cereal fractions in celiac disease. While early studies relied on crude indicators of celiac toxicity, the advent of jejunal biopsy and sophisticated immunohistochemical techniques has allowed accurate studies to be performed. Studies to determine the nature of the cereal component that is toxic to patients with celiac disease have concentrated on wheat because of its nutritional importance. A number of in vitro studies indicated the presence of one or more celiac-activating epitopes with the N-terminus of the A-gliadin molecule. In vivo challenge with three synthetic peptides subsequently indicated the toxicity of a peptide corresponding to amino acids 31 to 49 of A-gliadin. In vivo gluten challenge is the gold standard for the assessment of celiac toxicity; however, jejunal biopsy is a relatively invasive procedure, thus, other methods have been investigated. Direct infusion of the rectum with gluten has been shown to result in an increase in mucosal intraepithelial lymphocytes, occurring only in celiac patients. This method has been used to study the celiac toxicity of gliadin subfractions. The in vitro technique of small intestinal biopsy organ culture is also a useful tool and appears to give the same results as in vivo challenge. The importance of tiny amounts of gliadin in the diet, such as that which occurs in wheat starch, has been studied by in vivo challenge; this technique has clarified the position of oats in the gluten-free diet. Several studies suggest that this cereal may be included in the diet of most adult celiac patients. Studies of the transport of gliadin across the enterocyte following ingestion or challenge suggest that gliadin may be metabolized by a different pathway in celiac disease. This could result in an abnormal presentation to the immune system, triggering a pathogenic rather than a tolerogenic response.

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Studies in vivo of ω-gliadins in gluten sensitivity (coeliac sprue disease)

Cited by 28 publications

References 36 publications

Characterization of the 1B‐Type ω‐Gliadins from Triticum aestivum Cultivar Butte

Characterization of the 1B‐Type ω‐Gliadins from Triticum aestivum Cultivar Butte

Innate and adaptive immunity: the Yin and Yang of celiac disease

In vivo gluten challenge in coeliac disease

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