Bernardo, DSánchez, BAl-Hassi, Hafid OmarMann, ERUrdaci, MCKnight, SCMargolles, A2020-07-172020-07-172012-05-14: Bernardo D, Sa´nchez B, Al-Hassi HO, Mann ER, Urdaci MC, et al. (2012) Microbiota/Host Crosstalk Biomarkers: Regulatory Response of Human Intestinal Dendritic Cells Exposed to Lactobacillus Extracellular Encrypted Peptide. PLoS ONE 7(5): e36262. doi:10.1371/journal.pone.00362621932-620322606249 (pubmed)10.1371/journal.pone.0036262http://hdl.handle.net/2436/623369© 2012 The Authors. Published by Public Library of Science. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.1371/journal.pone.0036262The human gastrointestinal tract is exposed to a huge variety of microorganisms, either commensal or pathogenic; at this site, a balance between immunity and immune tolerance is required. Intestinal dendritic cells (DCs) control the mechanisms of immune response/tolerance in the gut. In this paper we have identified a peptide (STp) secreted by Lactobacillus plantarum, characterized by the abundance of serine and threonine residues within its sequence. STp is encoded in one of the main extracellular proteins produced by such species, which includes some probiotic strains, and lacks cleavage sites for the major intestinal proteases. When studied in vitro, STp expanded the ongoing production of regulatory IL-10 in human intestinal DCs from healthy controls. STp-primed DC induced an immunoregulatory cytokine profile and skin-homing profile on stimulated T-cells. Our data suggest that some of the molecular dialogue between intestinal bacteria and DCs may be mediated by immunomodulatory peptides, encoded in larger extracellular proteins, secreted by commensal bacteria. These peptides may be used for the development of nutraceutical products for patients with IBD. In addition, this kind of peptides seem to be absent in the gut of inflammatory bowel disease patients, suggesting a potential role as biomarker of gut homeostasis. © 2012 Bernardo et al.application/pdfenLicence for published version: Creative Commons Attribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/IntestinesDendritic CellsHumansLactobacillus plantarumInflammatory Bowel DiseasesBacterial ProteinsDNA, BacterialBiological MarkersImmune ToleranceAmino Acid SequenceBase SequenceProbioticsMolecular Sequence DataMetagenomeJournal article1932-6203PLoS ONE2020-06-30