title: Serotype-dependent response of human dendritic cells stimulated with Aggregatibacter actinomycetemcomitans.
abstract: OBJECTIVE
  Different serotypes of Aggregatibacter actinomycetemcomitans have been described based on the lipopolysaccharide (LPS)-O-polysaccharide antigenicity. In turn, a distinct effect of A. actinomycetemcomitans serotypes has been described on cell proliferation and pro-inflammatory cytokine production in different human cells. This study was aimed to investigate the differential dendritic cell (DC) response when stimulated with different bacterial strains belonging to the most prevalent serotypes of A. actinomycetemcomitans (a-c).
  
  
  METHODS
  Dendritic cells were obtained from healthy subjects and stimulated with increasing multiplicity of infection (MOI = 10(-1) -10(2)) of A. actinomycetemcomitans, serotypes a-c, or their lipopolysaccharide (10-50 ng/ml). The levels for interferon (IFN)-γ, tumour necrosis factor (TNF)-α, interleukin (IL)-1β, IL-5, IL-6, IL-10, IL-12 and IL-23 were quantified by real-time RT-PCR and ELISA.
  
  
  RESULTS
  Variable DC responses were detected when stimulated with the different strains of A. actinomycetemcomitans. DCs stimulated with A. actinomycetemcomitans strains belonging to the serotype b or their purified LPS expressed higher levels of IL-1β, IL-6, IL-12, IL-23, IFN-γ and TNF-α than DCs stimulated with the other serotypes.
  
  
  CONCLUSIONS
  Aggregatibacter actinomycetemcomitans strains belonging to the serotype b demonstrated a higher capacity to trigger Th1 and Th17-type cytokine production on DCs. These increased potential is likely explained by a higher immunogenicity of their LPS.
authors.affiliation: Periodontal Biology Laboratory, Department of Conservative Dentistry, Dental School, Universidad de Chile, Santiago de Chile, Chile.
authors.forename: Jaime
authors.initials: J
authors.lastname: Díaz-Zúñiga
authors.forename: Juan Pablo
authors.initials: JP
authors.lastname: Yáñez
authors.forename: Carla
authors.initials: C
authors.lastname: Alvarez
authors.forename: Samanta
authors.initials: S
authors.lastname: Melgar-Rodríguez
authors.forename: Marcela
authors.initials: M
authors.lastname: Hernández
authors.forename: Mariano
authors.initials: M
authors.lastname: Sanz
authors.forename: Rolando
authors.initials: R
authors.lastname: Vernal
mesh_terms: D016976:Aggregatibacter actinomycetemcomitans / Q000145:classification / Q000276:immunology*; D002454:Cell Differentiation / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology / Q000382:microbiology*; D006801:Humans; D007371:Interferon-gamma / Q000032:analysis; D016753:Interleukin-10 / Q000032:analysis; D018664:Interleukin-12 / Q000032:analysis; D053583:Interleukin-1beta / Q000032:analysis; D053759:Interleukin-23 / Q000032:analysis; D015848:Interleukin-5 / Q000032:analysis; D015850:Interleukin-6 / Q000032:analysis; D008070:Lipopolysaccharides / Q000276:immunology; D009000:Monocytes / Q000276:immunology; D019081:O Antigens / Q000276:immunology; D065288:Serogroup; D018417:Th1 Cells / Q000276:immunology; D058504:Th17 Cells / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis
chemical_list: C508609:IL10 protein, human; C508599:IL5 protein, human; C508600:IL6 protein, human; D053583:Interleukin-1beta; D053759:Interleukin-23; D015848:Interleukin-5; D015850:Interleukin-6; D008070:Lipopolysaccharides; D019081:O Antigens; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D018664:Interleukin-12; D007371:Interferon-gamma
keywords: Aggregatibacter actinomycetemcomitans; LPS; cytokines; dendritic cells; lipopolysaccharide; serotypes