title: Toll-like receptors and cytokines are upregulated during Helicobacter pylori infection in children.
abstract: OBJECTIVE
  Helicobacter pylori infection is mainly acquired during childhood, and establishes a chronic infection that may lead to peptic ulcer or gastric cancer during adulthood. Toll-like receptors (TLRs) are expressed by distinct cell types throughout the gastrointestinal tract, and play an important role in regulation of the innate immune response. Few works have addressed TLRs expression in gastric epithelia of adults, and scarce studies have done it in children. The aim of this work was to analyze the expression of TLR2, TLR4, TLR5, TLR9, and IL-8, IL-10 and TNF-α in the gastric mucosa of children with and without H. pylori infection.
  
  
  METHODS
  Gastric biopsies were collected by endoscopy from 50 children with recurrent abdominal pain, 25 with H. pylori infection and 25 without infection. In the gastric biopsies the expression of TLRs and cytokines was studied by immunohistochemistry, and the degree of mucosal inflammation was determined using the Sydney system.
  
  
  RESULTS
  We found that H. pylori infection was associated with a significant increased expression of TLRs 2, 4, 5 and 9, although expression varied between surface epithelia and glands. Epithelial cells expressing IL-8, IL-10 and TNF-α were increased in gastric mucosa of children with H. pylori infection.
  
  
  CONCLUSIONS
  This study shows the gastric epithelia of children respond to H. pylori infection by increasing the expression of TLR2, TLR4, TLR5, TLR9 and the cytokines IL-8, IL-10 and TNF-α.
authors.affiliation: Unidad de Investigación Médica en Enfermedades Infecciosas, Centro Médico Nacional Siglo XXI, IMSS, Mexico City, México.
authors.forename: Hugo
authors.initials: H
authors.lastname: Lagunes-Servin
authors.forename: Javier
authors.initials: J
authors.lastname: Torres
authors.forename: Carmen
authors.initials: C
authors.lastname: Maldonado-Bernal
authors.forename: Martha
authors.initials: M
authors.lastname: Pérez-Rodríguez
authors.forename: Sara
authors.initials: S
authors.lastname: Huerta-Yépez
authors.forename: Armando
authors.initials: A
authors.lastname: Madrazo de la Garza
authors.forename: Leopoldo
authors.initials: L
authors.lastname: Muñoz-Pérez
authors.forename: Lourdes
authors.initials: L
authors.lastname: Flores-Luna
authors.forename: Guillermo
authors.initials: G
authors.lastname: Ramón-García
authors.forename: Margarita
authors.initials: M
authors.lastname: Camorlinga-Ponce
mesh_terms: D000293:Adolescent; D002648:Child; D016207:Cytokines / Q000235:genetics* / Q000378:metabolism; D005753:Gastric Mucosa / Q000378:metabolism; D016481:Helicobacter Infections / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology; D016480:Helicobacter pylori / Q000502:physiology*; D006801:Humans; D008297:Male; D051193:Toll-Like Receptors / Q000235:genetics* / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D016207:Cytokines; D051193:Toll-Like Receptors
keywords: Children; H. pylori; TLR; cytokines; gastric mucosa