Effects of palladium nanoparticles on the cytokine release from peripheral blood mononuclear cells of palladium-sensitized women

OBJECTIVE: To investigate the effects of palladium (Pd) nanoparticles on cytokine release from peripheral blood mononuclear cells (PBMCs) of control or Pd-sensitized nonatopic women. METHODS: TNF-alpha, IL-5, IL-10 and IFN-gamma release and/or expression from PBMCs incubated in presence of 5 to 10 nm Pd nanoparticles or Pd salt (potassium hexachloropalladate) were determined by enzyme-linked immunosorbent assay and reverse transcription-polymerase chain reaction analysis. Transmission electron microscopy was performed. RESULTS: In lipopolysaccharide-stimulated PBMCs from controls, Pd salt inhibited IFN-gamma and IL-10 release, whereas Pd nanoparticles enhanced IFN-gamma release and inhibited TNF-alpha secretion. In lipopolysaccharide-stimulated PBMCs from Pd-sensitized women showing high IFN-gamma release, Pd nanoparticles inhibited TNF-alpha release and Pd salt IL-10 release. TNF-alpha and IFN-gamma release and messenger RNA expression were correlated. Transmission electronmicroscopy demonstrated uptake of nanoparticles in the endocytic compartment and activation of autophagy. CONCLUSIONS: Palladium ions and nanoparticles exert different effects in vitro on the expression and release of cytokines.