Effects of titanium(iv) ions on human monocyte-derived dendritic cells

文献情報

出版日 2009-01-30

DOI 10.1039/B820871A

インパクトファクター 0

著者

Peta Clode, Martin Saunders

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要旨

Orthopaedic metal implants composed of titanium are routinely used in bone fracture repair and for joint replacement therapies. A considerable fraction of implant recipients are unable to benefit due to implant failure resulting from aseptic loosening, while others may experience cutaneous sensitivity to titanium after implantation. An adaptive immune reactivity towards titanium ions, originating from the biocorrosion of the implants, could play a role. As an initiator of the adaptive immune response, dendritic cells (DC) were studied for uptake and characteristics after titanium exposure. Energy filtered transmission electron microscopy showed uptake of titanium(IV) (Ti(IV)) ions by DCsin vitro and co-localisation with phosphorus-rich cell structures of the DC membranes (phospholipids), cytoplasm (ribosomes and phosphorylated proteins) and the nucleus (DNA). DC maturation and function were investigated by measuring cell surface marker expression by flow cytometry. After exposure, DCs showed a decrease in MHC class II (HLA-DR), co-stimulatory molecules (CD40, CD80 & CD86) and chemokine receptors (CCR) 6 and CCR7 but an increase in CCR4 after Ti(IV) treatment. However, Ti(IV) treated DCs had an increased stimulatory capacity towards allogenic lymphocytes. A Ti(IV) concentration dependant increase of IL-12p70 was observed amidst decrease of the other measured cytokines (TGF-β1 and TGF-β2). Hence, Ti(IV) alters DC properties, resulting in an enhanced T lymphocyte reactivity and deviation towards a Th1 type immune response. This effect may be responsible for the inflammatory side effects of titanium implants seen in patients.

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Metallomics

CiteScore: 7

自己引用率: 6.9%

年間論文数: 77

Metallomics publishes cutting-edge investigations aimed at elucidating the identification, distribution, dynamics, role and impact of metals and metalloids in biological systems. Studies that address the “what, where, when, how and why” of these inorganic elements in cells, tissues, organisms, and various environmental niches are welcome, especially those employing multidisciplinary approaches drawn from the analytical, bioinorganic, medicinal, environmental, biophysical, cell biology, plant biology and chemical biology communities. We are particularly interested in articles that enhance our chemical and/or physical understanding of the molecular mechanisms of metal-dependent life processes, and those that probe the common space between metallomics and other ‘omics approaches to uncover new insights into biological processes. Metallomics seeks to position itself at the forefront of those advances in analytical chemistry destined to clarify the enormous complexity of biological systems. As such, we particularly welcome those papers that outline cutting-edge analytical technologies, e.g., in the development and application of powerful new imaging, spectroscopic and mass spectrometric modalities. Work that describes new insights into metal speciation, trafficking and dynamics in complex systems or as a function of microenvironment are also strongly encouraged. Studies that examine the interconnectivity of metal-dependent processes with systems level responses relevant to organismal health or disease are also strongly encouraged, for example those that probe the effect of chemical exposure on metal homeostasis or the impact of metal-based drugs on cellular processes.