title: Human immune response towards recombinant Helicobacter pylori urease and cellular fractions.
abstract: Vaccination against Helicobacter pylori is of particular clinical interest. Recombinant urease, the major protein in H. pylori, has been used for mucosal vaccination trials in different animal models, but was found to be ineffective in humans. The current study therefore investigated the human immune response towards recombinant H. pylori urease A and B (rUreA/B) expressed in E. coli compared to different cellular fractions of H. pylori (cytosol, total, inner and outer membrane). Monocyte-derived dendritic cells (Mo-DC) were generated from monocytes isolated by magnetic antigen cell separation (MACS) from healthy volunteers and cultured in the presence of hrIL-4 and hrGM-CSF. Mo-DC were stimulated for 48h with the recombinant proteins (1 microg/ml) or cellular fractions (1-10 microg/ml) and cytokine release was determined in the culture supernatant by ELISA. rUreA and rUreB were effective in inducing IL-12 secretion (6-10 fold) and, to a much lesser extent (2 fold), IL-10 secretion from Mo-DC. Total and outer membrane preparations from H. pylori stimulated IL-12 secretion significantly, and were even more potent than intact bacteria. Mo-DCs pulsed with rUreA activated allogenic CD56+ NK-cells, as determined by TNF-alpha and IFN-gamma secretion, but not allogenic CD4+/CD45RA+ naïve T-cells. In contrast, Mo-DCs pulsed with H. pylori total membrane or outer membrane preparations activated allogenic naive T-cells in co-culture systems, as determined by increased TNF-alpha secretion. It appears that outer membrane preparations of H. pylori, but not recombinant urease are more effective in inducing a Th1 polarized response in humans in vitro.
authors.affiliation: II. Medical Department, Gastroenterology, Hepatology, Infectious Diseases, Klinikum rechts der Isar, Technical University, 81675 Munich, Germany.
authors.forename: Petra
authors.initials: P
authors.lastname: Voland
authors.forename: Marco
authors.initials: M
authors.lastname: Zeitner
authors.forename: Nadia
authors.initials: N
authors.lastname: Hafsi
authors.forename: Christian
authors.initials: C
authors.lastname: Prinz
mesh_terms: D001428:Bacterial Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D002462:Cell Membrane / Q000276:immunology*; D002478:Cells, Cultured; D016207:Cytokines / Q000096:biosynthesis; D003600:Cytosol / Q000276:immunology*; D003713:Dendritic Cells / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000276:immunology; D016480:Helicobacter pylori / Q000201:enzymology / Q000235:genetics / Q000276:immunology*; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis; D016753:Interleukin-10 / Q000032:analysis; D018664:Interleukin-12 / Q000032:analysis; D015847:Interleukin-4 / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology; D008213:Lymphocyte Activation; D013601:T-Lymphocytes / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis; D014510:Urease / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*
chemical_list: D001428:Bacterial Vaccines; D016207:Cytokines; C508598:IL4 protein, human; D014409:Tumor Necrosis Factor-alpha; D014614:Vaccines, Synthetic; D016753:Interleukin-10; D018664:Interleukin-12; D015847:Interleukin-4; D007371:Interferon-gamma; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D014510:Urease