{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,25]],"date-time":"2026-01-25T16:27:47Z","timestamp":1769358467163,"version":"3.49.0"},"reference-count":39,"publisher":"MDPI AG","issue":"23","license":[{"start":{"date-parts":[[2020,12,6]],"date-time":"2020-12-06T00:00:00Z","timestamp":1607212800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Gluten fragments released in gut of celiac individuals activate the innate or adaptive immune systems. The molecular mechanisms associated with the adaptive response involve a series of immunodominant gluten peptides which are mainly recognized by human leucocyte antigen (HLA)-DQ2.5 and HLA-DQ8. Other peptides, such as A-gliadin P31\u201343, are not recognized by HLA and trigger innate responses by several routes not yet well detailed. Among the gluten fragments known to be active in Celiac disease, here we focus on the properties of all gluten peptides with known tri-dimensional structure either those locked into HLA-DQ complexes whose crystals were X-ray analyzed or characterized in solution as free forms. The aim of this work was to find the structural reasons why some gluten peptides prompt the adaptive immune systems while others do not, by apparently involving just the innate immune routes. We propose that P31\u201343 is a non-adaptive prompter because it is not a good ligand for HLA-DQ. Even sharing a similar ability to adopt polyproline II structure with the adaptive ones, the way in which the proline residues are located along the sequence disfavors a productive P31\u201343-HLA-DQ binding.<\/jats:p>","DOI":"10.3390\/ijms21239301","type":"journal-article","created":{"date-parts":[[2020,12,7]],"date-time":"2020-12-07T12:24:39Z","timestamp":1607343879000},"page":"9301","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":13,"title":["Structural Perspective of Gliadin Peptides Active in Celiac Disease"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3758-2716","authenticated-orcid":false,"given":"Lucia","family":"Falcigno","sequence":"first","affiliation":[{"name":"Department of Pharmacy, University of Naples Federico II, Via Mezzocannone 16, 80134 Naples, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Luisa","family":"Calvanese","sequence":"additional","affiliation":[{"name":"Department of Pharmacy, University of Naples Federico II, Via Mezzocannone 16, 80134 Naples, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mariangela","family":"Conte","sequence":"additional","affiliation":[{"name":"Department of Translational Medical Science, Section of Pediatrics, University of Naples Federico II, 80131 Naples, Italy"},{"name":"European Laboratory for the Investigation of Food Induced Diseases (ELFID), University of Naples Federico II, 80131 Naples, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Merlin","family":"Nanayakkara","sequence":"additional","affiliation":[{"name":"Department of Translational Medical Science, Section of Pediatrics, University of Naples Federico II, 80131 Naples, Italy"},{"name":"European Laboratory for the Investigation of Food Induced Diseases (ELFID), University of Naples Federico II, 80131 Naples, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Maria Vittoria","family":"Barone","sequence":"additional","affiliation":[{"name":"Department of Translational Medical Science, Section of Pediatrics, University of Naples Federico II, 80131 Naples, Italy"},{"name":"European Laboratory for the Investigation of Food Induced Diseases (ELFID), University of Naples Federico II, 80131 Naples, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gabriella","family":"D\u2019Auria","sequence":"additional","affiliation":[{"name":"Department of Pharmacy, University of Naples Federico II, Via Mezzocannone 16, 80134 Naples, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,12,6]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"480","DOI":"10.1038\/nsmb.2817","article-title":"T-cell receptor recognition of HLA-DQ2\u2013gliadin complexes associated with celiac disease","volume":"21","author":"Petersen","year":"2014","journal-title":"Nat. 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