Pepsin digest of wheat gliadin fraction increases production of IL-1β via TLR4/MyD88/TRIF/MAPK/NF-κB signaling pathway and an NLRP3 inflammasome activation

• Published in: PloS one Vol. 8; no. 4; p. e62426
• Main Authors: Palová-Jelínková, Lenka, Dáňová, Klára, Drašarová, Hana, Dvořák, Miloš, Funda, David P, Fundová, Petra, Kotrbová-Kozak, Anna, Černá, Marie, Kamanová, Jana, Martin, Stefan F, Freudenberg, Marina, Tučková, Ludmila
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 29.04.2013; Public Library of Science (PLoS)
• Subjects: Activation; Adaptor Proteins, Vesicular Transport - genetics; Adaptor Proteins, Vesicular Transport - immunology; Adenosine triphosphate; Adult; Agricultural production; Animals; Apoptosis; Autoimmune diseases; Biology; Bone marrow; Carrier Proteins - genetics; Carrier Proteins - immunology; Caspase; Caspase-1; Celiac Disease; Chemokines; Cytokines; Dendritic cells; Efflux; Female; Gene Expression Regulation - drug effects; Gene Expression Regulation - immunology; Gliadin; Gliadin - chemistry; Gliadin - immunology; Gluten; Humans; Immunology; Inflammasomes; Inflammasomes - drug effects; Inflammasomes - genetics; Inflammasomes - immunology; Inflammation; Interferon; Interleukin 1; Interleukin 18; Interleukin-1beta - genetics; Interleukin-1beta - immunology; Leukocytes (mononuclear); Leukocytes, Mononuclear - drug effects; Leukocytes, Mononuclear - immunology; Leukocytes, Mononuclear - pathology; Lymphocytes; Male; MAP kinase; Medicine; Mice; Mice, Knockout; Middle Aged; Mitogen-Activated Protein Kinases - genetics; Mitogen-Activated Protein Kinases - immunology; Monocytes; MyD88 protein; Myeloid Differentiation Factor 88 - genetics; Myeloid Differentiation Factor 88 - immunology; NF-κB protein; NLR Family, Pyrin Domain-Containing 3 Protein; Oxidative stress; Pathogenesis; Patients; Pepsin; Pepsin A; Peptide Fragments - pharmacology; Peripheral blood mononuclear cells; Primary Cell Culture; Proteins; Pyrin protein; Signal transduction; Signal Transduction - drug effects; Signal Transduction - genetics; Signal Transduction - immunology; Signaling; Small intestine; Toll-Like Receptor 2 - genetics; Toll-Like Receptor 2 - immunology; Toll-Like Receptor 4 - genetics; Toll-Like Receptor 4 - immunology; Toll-like receptors; Wheat; Czech Republic
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0062426

Celiac disease (CD) is a gluten-responsive, chronic inflammatory enteropathy. IL-1 cytokine family members IL-1β and IL-18 have been associated with the inflammatory conditions in CD patients. However, the mechanisms of IL-1 molecule activation in CD have not yet been elucidated. We show in this study that peripheral blood mononuclear cells (PBMC) and monocytes from celiac patients responded to pepsin digest of wheat gliadin fraction (PDWGF) by a robust secretion of IL-1β and IL-1α and a slightly elevated production of IL-18. The analysis of the upstream mechanisms underlying PDWGF-induced IL-1β production in celiac PBMC show that PDWGF-induced de novo pro-IL-1β synthesis, followed by a caspase-1 dependent processing and the secretion of mature IL-1β. This was promoted by K+ efflux and oxidative stress, and was independent of P2X7 receptor signaling. The PDWGF-induced IL-1β release was dependent on Nod-like receptor family containing pyrin domain 3 (NLRP3) and apoptosis-associated speck like protein (ASC) as shown by stimulation of bone marrow derived dendritic cells (BMDC) from NLRP3(-/-) and ASC(-/-) knockout mice. Moreover, treatment of human PBMC as well as MyD88(-/-) and Toll-interleukin-1 receptor domain-containing adaptor-inducing interferon-β (TRIF)(-/-) BMDC illustrated that prior to the activation of caspase-1, the PDWGF-triggered signal constitutes the activation of the MyD88/TRIF/MAPK/NF-κB pathway. Moreover, our results indicate that the combined action of TLR2 and TLR4 may be required for optimal induction of IL-1β in response to PDWGF. Thus, innate immune pathways, such as TLR2/4/MyD88/TRIF/MAPK/NF-κB and an NLRP3 inflammasome activation are involved in wheat proteins signaling and may play an important role in the pathogenesis of CD.