title: Human buccal epithelium acquires microbial hyporesponsiveness at birth, a role for secretory leukocyte protease inhibitor.
abstract: OBJECTIVE
  Repetitive interaction with microbial stimuli renders epithelial cells (ECs) hyporesponsive to microbial stimulation. Previously, we have reported that buccal ECs from a subset of paediatric patients with Crohn's disease are not hyporesponsive and spontaneously released chemokines. We now aimed to identify kinetics and mechanisms of acquisition of hyporesponsiveness to microbial stimulation using primary human buccal epithelium.
  
  
  METHODS
  Buccal ECs collected directly after birth and in later stages of life were investigated. Chemokine release and regulatory signalling pathways were studied using primary buccal ECs and the buccal EC line TR146. Findings were extended to the intestinal mucosa using murine model systems.
  
  
  RESULTS
  Directly after birth, primary human buccal ECs spontaneously produced the chemokine CXCL-8 and were responsive to microbial stimuli. Within the first weeks of life, these ECs attained hyporesponsiveness, associated with inactivation of the NF-κB pathway and upregulation of the novel NF-κB inhibitor SLPI but no other known NF-κB inhibitors. SLPI protein was abundant in the cytoplasm and the nucleus of hyporesponsive buccal ECs. Knock-down of SLPI in TR146-buccal ECs induced loss of hyporesponsiveness with increased NF-κB activation and subsequent chemokine release. This regulatory mechanism extended to the intestine, as colonisation of germfree mice elicited SLPI expression in small intestine and colon. Moreover, SLPI-deficient mice had increased chemokine expression in small intestinal and colonic ECs.
  
  
  CONCLUSIONS
  We identify SLPI as a new player in acquisition of microbial hyporesponsiveness by buccal and intestinal epithelium in the first weeks after microbial colonisation.
authors: Laboratory of Pediatrics, Division of Gastroenterology and Nutrition, Erasmus MC, Rotterdam, The Netherlands.
authors: Celia L
authors: CL
authors: Menckeberg
authors: Laboratory of Pediatrics, Division of Gastroenterology and Nutrition, Erasmus MC, Rotterdam, The Netherlands Department of Pulmonary Diseases, Sophia Children's Hospital, Rotterdam, The Netherlands Department of Pediatrics, University Hospital Ghent, Ghent, Belgium.
authors: Jeroen
authors: J
authors: Hol
authors: Laboratory of Pediatrics, Division of Gastroenterology and Nutrition, Erasmus MC, Rotterdam, The Netherlands.
authors: Ytje
authors: Y
authors: Simons-Oosterhuis
authors: Laboratory of Pediatrics, Division of Gastroenterology and Nutrition, Erasmus MC, Rotterdam, The Netherlands.
authors: H Rolien C
authors: HR
authors: Raatgeep
authors: Laboratory of Pediatrics, Division of Gastroenterology and Nutrition, Erasmus MC, Rotterdam, The Netherlands Department of Pulmonary Diseases, Sophia Children's Hospital, Rotterdam, The Netherlands.
authors: Lilian F
authors: LF
authors: de Ruiter
authors: Laboratory of Pediatrics, Division of Gastroenterology and Nutrition, Erasmus MC, Rotterdam, The Netherlands.
authors: Dicky J
authors: DJ
authors: Lindenbergh-Kortleve
authors: Laboratory of Pediatrics, Division of Gastroenterology and Nutrition, Erasmus MC, Rotterdam, The Netherlands.
authors: Anita M
authors: AM
authors: Korteland-van Male
authors: Laboratory of Microbiology and Host Microbe Interactomics Group, Wageningen University, Wageningen, The Netherlands Department of Industrial Biotechnology, GEBRI, Sadat City University, Sadat City, Egypt.
authors: Sahar
authors: S
authors: El Aidy
authors: Laboratory of Pediatrics, Division of Gastroenterology and Nutrition, Erasmus MC, Rotterdam, The Netherlands.
authors: Pieter P E
authors: PP
authors: van Lierop
authors: Laboratory of Microbiology and Host Microbe Interactomics Group, Wageningen University, Wageningen, The Netherlands.
authors: Michiel
authors: M
authors: Kleerebezem
authors: Department of Pediatrics, Maasstad Hospital, Rotterdam, The Netherlands.
authors: Michael
authors: M
authors: Groeneweg
authors: Department of Molecular Cell Biology and Immunology, VU University Medical Center, Amsterdam, The Netherlands.
authors: Georg
authors: G
authors: Kraal
authors: Department of Pulmonary Diseases, Sophia Children's Hospital, Rotterdam, The Netherlands.
authors: Beatrix E
authors: BE
authors: Elink-Schuurman
authors: Department of Pulmonary Diseases, Sophia Children's Hospital, Rotterdam, The Netherlands.
authors: Johan C
authors: JC
authors: de Jongste
authors: Laboratory of Pediatrics, Division of Gastroenterology and Nutrition, Erasmus MC, Rotterdam, The Netherlands Wilhelmina Children's Hospital, Utrecht, The Netherlands.
authors: Edward E S
authors: EE
authors: Nieuwenhuis
authors: Laboratory of Pediatrics, Division of Gastroenterology and Nutrition, Erasmus MC, Rotterdam, The Netherlands.
authors: Janneke N
authors: JN
authors: Samsom
mesh_terms: D000328:Adult; D000375:Aging / Q000276:immunology*; D000818:Animals; D002478:Cells, Cultured; D054426:Chemokine CXCL2 / Q000378:metabolism; D015536:Down-Regulation; D004848:Epithelium / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology*; D055785:Gene Knockdown Techniques; D006801:Humans; D007108:Immune Tolerance; D007223:Infant; D007231:Infant, Newborn; D016209:Interleukin-8 / Q000378:metabolism; D007413:Intestinal Mucosa / Q000166:cytology / Q000382:microbiology; D051379:Mice; D008875:Middle Aged; D009061:Mouth Mucosa / Q000166:cytology* / Q000382:microbiology*; D016328:NF-kappa B / Q000378:metabolism; D010457:Peptidoglycan / Q000494:pharmacology; D053481:Secretory Leukocyte Peptidase Inhibitor / Q000378:metabolism*
chemical_list: D054426:Chemokine CXCL2; D016209:Interleukin-8; D016328:NF-kappa B; D010457:Peptidoglycan; C506814:SLPI protein, human; D053481:Secretory Leukocyte Peptidase Inhibitor
keywords: Bacterial Interactions; Epithelial Cells; Gut Immunology; IBD Basic Research