title: Human dendritic cells respond to Helicobacter pylori, promoting NK cell and Th1-effector responses in vitro.
abstract: Helicobacter pylori infection leads to chronic gastric inflammation. The current study determined the response of human APCs, NK cells, and T cells toward the bacteria in vitro. Human monocyte-derived dendritic cells (DC) were incubated with bacteria for 48 h. Intact H. pylori at a multitude of infection 5 stimulated the expression of MHC class II (4- to 7-fold), CD80, and CD86 B7 molecules (10- to 12-fold) and the CD83 costimulatory molecule (>30-fold) as well as IL-12 secretion (>50-fold) in DCs, and thereby, strongly induced their maturation and activation. CD56(+)/CD4(-) NK cells, as well as CD4(+)/CD45RA(+) naive T cells, were isolated and incubated with DCs pulsed with intact bacteria or different cellular fractions. Coculture of H. pylori-pulsed DCs with NK cells strongly potentiated the secretion of TNF-alpha and IFN-gamma. Coculture of naive T cells with H. pylori-pulsed DCs significantly enhanced TNF-alpha, IFN-gamma, and IL-2 secretion as well as T-bet mRNA levels, while GATA-3 mRNA was lowered. However, the effect appeared attenuated compared with coculture with Escherichia coli. A greater stimulation was seen with naive T cells and DCs pulsed with H. pylori membrane preparations. Intact H. pylori potently induced the maturation and activation of human monocyte-derived DC and thereby promote NK and Th1 effector responses. The strong activation of NK cells may be important for the innate immune response. Th1-polarized T cells were induced especially by incubation with membrane preparations of H. pylori, suggesting that membrane proteins may account for the specific adaptive immune response.
authors.affiliation: Department of Medicine II, Technical University, Munich, Germany.
authors.forename: Nadia
authors.initials: N
authors.lastname: Hafsi
authors.forename: Petra
authors.initials: P
authors.lastname: Voland
authors.forename: Susanne
authors.initials: S
authors.lastname: Schwendy
authors.forename: Roland
authors.initials: R
authors.lastname: Rad
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Reindl
authors.forename: Markus
authors.initials: M
authors.lastname: Gerhard
authors.forename: Christian
authors.initials: C
authors.lastname: Prinz
mesh_terms: D002454:Cell Differentiation / Q000276:immunology; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics; D003713:Dendritic Cells / Q000276:immunology*; D005434:Flow Cytometry; D050990:GATA3 Transcription Factor; D016481:Helicobacter Infections / Q000276:immunology*; D016480:Helicobacter pylori / Q000276:immunology*; D006801:Humans; D066298:In Vitro Techniques; D007694:Killer Cells, Natural / Q000276:immunology*; D016133:Polymerase Chain Reaction; D020825:T-Box Domain Proteins; D013601:T-Lymphocytes / Q000378:metabolism; D018417:Th1 Cells / Q000276:immunology*; D015534:Trans-Activators / Q000096:biosynthesis / Q000235:genetics; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics; D000098815:T-bet Transcription Factor
chemical_list: D004268:DNA-Binding Proteins; D050990:GATA3 Transcription Factor; C494749:GATA3 protein, human; D020825:T-Box Domain Proteins; D000098815:T-bet Transcription Factor; D015534:Trans-Activators; D014157:Transcription Factors