title: Helicobacter pylori induces in-vivo expansion of human regulatory T cells through stimulating interleukin-1β production by dendritic cells.
abstract: Helicobacter pylori is one of the most common infections in the world. Despite inciting inflammation, immunological clearance of the pathogen is often incomplete. CD4(+) CD25(hi) forkhead box protein 3 (FoxP3(+)) regulatory T cells (T(regs)) are potent suppressors of different types of immune responses and have been implicated in limiting inflammatory responses to H. pylori. Investigating the influence of H. pylori on T(reg) function and proliferation, we found that H. pylori-stimulated dendritic cells (DCs) induced proliferation in T(regs) and impaired their suppressive capability. This effect was mediated by interleukin (IL)-1β produced by H. pylori-stimulated DCs. These data correlated with in-vivo observations in which H. pylori(+) gastric mucosa contained more T(regs) in active cell division than uninfected stomachs. Inciting local proliferation of T(regs) and inhibiting their suppressive function may represent a mechanism for the chronic gastritis and carcinogenesis attributable to H. pylori.
authors.affiliation: MRC Centre for Transplantation, National Institute for Health Research (NIHR), Comprehensive Biomedical Research Centre at Guy's and St Thomas', NHS Foundation Trust, King's College London, London, UK.
authors.forename: P J
authors.initials: PJ
authors.lastname: Mitchell
authors.forename: B
authors.initials: B
authors.lastname: Afzali
authors.forename: H
authors.initials: H
authors.lastname: Fazekasova
authors.forename: D
authors.initials: D
authors.lastname: Chen
authors.forename: N
authors.initials: N
authors.lastname: Ali
authors.forename: N
authors.initials: N
authors.lastname: Powell
authors.forename: G M
authors.initials: GM
authors.lastname: Lord
authors.forename: R I
authors.initials: RI
authors.lastname: Lechler
authors.forename: G
authors.initials: G
authors.lastname: Lombardi
mesh_terms: D003713:Dendritic Cells / Q000276:immunology*; D005753:Gastric Mucosa / Q000276:immunology / Q000378:metabolism / Q000382:microbiology; D016481:Helicobacter Infections / Q000276:immunology / Q000378:metabolism; D016480:Helicobacter pylori / Q000276:immunology*; D006801:Humans; D053583:Interleukin-1beta / Q000096:biosynthesis*; D015850:Interleukin-6 / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism; D050378:T-Lymphocytes, Regulatory / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
chemical_list: D053583:Interleukin-1beta; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha