title: Selective probiotic bacteria induce IL-10-producing regulatory T cells in vitro by modulating dendritic cell function through dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin.
abstract: BACKGROUND
  Lactobacilli are probiotic bacteria that are frequently tested in the management of allergic diseases or gastroenteritis. It is hypothesized that these probiotics have immunoregulatory properties and promote mucosal tolerance, which is in part mediated by regulatory T cells (Treg cells). On the basis of pathogenic or tissue-specific priming, dendritic cells (DC) acquire different T cell-instructive signals and drive the differentiation of naive T H cells into either T H 1, T H 2, or regulatory effector T cells.
  
  
  OBJECTIVE
  We studied in what way different species of lactobacilli prime human DCs for their ability to drive Treg cells.
  
  
  METHODS
  Human monocyte-derived DCs were cultured in vitro with lactobacilli of different species.
  
  
  RESULTS
  Two different species of lactobacilli, Lactobacillus reuteri and Lactobacillus casei , but not Lactobacillus plantarum, prime monocyte-derived DCs to drive the development of Treg cells. These Treg cells produced increased levels of IL-10 and were capable of inhibiting the proliferation of bystander T cells in an IL-10-dependent fashion. Strikingly, both L reuteri and L casei , but not L plantarum , bind the C-type lectin DC-specific intercellular adhesion molecule 3-grabbing non-integrin (DC-SIGN). Blocking antibodies to DC-SIGN inhibited the induction of the Treg cells by these probiotic bacteria, stressing that ligation of DC-SIGN can actively prime DCs to induce Treg cells.
  
  
  CONCLUSIONS
  The targeting of DC-SIGN by certain probiotic bacteria might explain their beneficial effect in the treatment of a number of inflammatory diseases, including atopic dermatitis and Crohn's disease.
authors.affiliation: Department of Cell Biology and Histology, Academic Medical Center, University of Amsterdam, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands.
authors.forename: Hermelijn H
authors.initials: HH
authors.lastname: Smits
authors.forename: Anneke
authors.initials: A
authors.lastname: Engering
authors.forename: Desiree
authors.initials: D
authors.lastname: van der Kleij
authors.forename: Esther C
authors.initials: EC
authors.lastname: de Jong
authors.forename: Kim
authors.initials: K
authors.lastname: Schipper
authors.forename: Toni M M
authors.initials: TM
authors.lastname: van Capel
authors.forename: Bas A J
authors.initials: BA
authors.lastname: Zaat
authors.forename: Maria
authors.initials: M
authors.lastname: Yazdanbakhsh
authors.forename: Eddy A
authors.initials: EA
authors.lastname: Wierenga
authors.forename: Yvette
authors.initials: Y
authors.lastname: van Kooyk
authors.forename: Martien L
authors.initials: ML
authors.lastname: Kapsenberg
mesh_terms: D015703:Antigens, CD / Q000276:immunology*; D015815:Cell Adhesion Molecules; D002455:Cell Division; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000276:immunology*; D006801:Humans; D016753:Interleukin-10 / Q000096:biosynthesis* / Q000494:pharmacology; D007778:Lactobacillus; D007780:Lacticaseibacillus casei; D037181:Lectins, C-Type / Q000276:immunology; D009000:Monocytes / Q000276:immunology; D019936:Probiotics; D013045:Species Specificity; D013601:T-Lymphocytes / Q000276:immunology*; D015854:Up-Regulation
chemical_list: D015703:Antigens, CD; D015815:Cell Adhesion Molecules; C483616:ICAM3 protein, human; D037181:Lectins, C-Type; D016753:Interleukin-10