title: TiO(2) nanoparticles and bulk material stimulate human peripheral blood mononuclear cells.
abstract: Nanomaterials are increasingly produced and used throughout recent years. Consequently the probability of exposure to nanoparticles has risen. Because of their small 1-100nm size, the physicochemical properties of nanomaterials may differ from standard bulk materials and may pose a threat to human health. Only little is known about the effects of nanoparticles on the human immune system. In this study, we investigated the effects of TiO2 nanoparticles and bulk material in the in vitro model of human peripheral blood mononuclear cells (PBMC) and cytokine-induced neopterin formation and tryptophan breakdown was monitored. Both biochemical processes are closely related to the course of diseases like infections, atherogenesis and neurodegeneration. OCTi60 (25nm diameter) TiO2 nanoparticles and bulk material increased neopterin production in unstimulated PBMC and stimulated cells significantly, the effects were stronger for OCTi60 compared to bulk material, while P25 TiO2 (25nm diameter) nanoparticles had only little influence. No effect of TiO2 nanoparticles on tryptophan breakdown was detected in unstimulated cells, whereas in stimulated cells, IDO activity and IFN-γ production were suppressed but only at the highest concentrations tested. Because neopterin was stimulated and tryptophan breakdown was suppressed in parallel, data suggests that the total effect of particles would be strongly pro-inflammatory.
authors.affiliation: Division of Biological Chemistry, Biocenter, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Becker
authors.affiliation: Division of Biological Chemistry, Biocenter, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Schroecksnadel
authors.affiliation: Division of Biological Chemistry, Biocenter, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Simon
authors.initials: S
authors.lastname: Geisler
authors.affiliation: Laboratoire Lesion des Acides Nucleiques, CEA Grenoble, Grenoble, France.
authors.forename: Marie
authors.initials: M
authors.lastname: Carriere
authors.affiliation: Division of Medical Biochemistry, Biocenter, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Johanna M
authors.initials: JM
authors.lastname: Gostner
authors.affiliation: Central Institute of Blood Transfusion and Immunology, University Hospital, Innsbruck, Austria.
authors.forename: Harald
authors.initials: H
authors.lastname: Schennach
authors.affiliation: Service des Photons, Atomes et Molécules, Laboratoire Francis Perrin (CEA CNRS URA 2453), Saclay, Gif-sur Yvette, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Herlin
authors.affiliation: Division of Biological Chemistry, Biocenter, Innsbruck Medical University, Innsbruck, Austria. Electronic address: dietmar.fuchs@i-med.ac.at.
authors.forename: Dietmar
authors.initials: D
authors.lastname: Fuchs
mesh_terms: D002478:Cells, Cultured; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis; D053768:Metal Nanoparticles; D009000:Monocytes / Q000187:drug effects* / Q000378:metabolism; D019798:Neopterin / Q000096:biosynthesis; D014025:Titanium / Q000494:pharmacology*; D014364:Tryptophan / Q000378:metabolism
chemical_list: C009495:titanium dioxide; D019798:Neopterin; D007371:Interferon-gamma; D014364:Tryptophan; D014025:Titanium
keywords: Immune system; Indoleamine 2,3-dioxygenase; Nanoparticles; Neopterin; Titanium dioxide