Gold nanoparticles induce transcriptional activity of NF-κB in a B-lymphocyte cell line

Abstract

Gold nanoparticles (Au-NPs) have been designated as superior tools for biological applications owing to their characteristic surface plasmon absorption/scattering and amperometric (electron transfer) properties, in conjunction with low or no immediate toxicity towards biological systems. Many studies have shown the ease of designing application-based tools using Au-NPs but the interaction of this nanosized material with biomolecules in a physiological environment is an area requiring deeper investigation. Immune cells such as lymphocytes circulate through the blood and lymph and therefore are likely cellular components to come in contact with Au-NPs. The main aim of this study was to mechanistically determine the functional impact of Au-NPs on B-lymphocytes. Using a murine B-lymphocyte cell line (CH12.LX), treatment with citrate-stabilized 10 nm Au-NPs induced activation of an NF-κB-regulated luciferase reporter, which correlated with altered B lymphocyte function (i.e. increased antibody expression). TEM imaging demonstrated that Au-NPs can pass through the cellular membrane and therefore could interact with intracellular components of the NF-κB signaling pathway. Based on the inherent property of Au-NPs to bind to -thiol groups and the presence of cysteine residues on the NF-κB signal transduction proteins IκB kinases (IKK), proteins specifically bound to Au-NPs were extracted from CH12.LX cellular lysate exposed to 10 nm Au-NPs. Electrophoresis identified several bands, of which IKKα and IKKβ were immunoreactive. Further evaluation revealed activation of the canonical NF-κB signaling pathway as evidenced by IκBα phosphorylation at serine residues 32 and 36 followed by IκBα degradation and increased nuclear RelA. Additionally, expression of an IκBα super-repressor (resistant to proteasomal degradation) reversed Au-NP-induced NF-κB activation. Altered NF-κB signaling and cellular function in B-lymphocytes suggests a potential for off-target effects with in vivo applications of gold nanomaterials and underscores the need for more studies evaluating the interactions of nanomaterials with biomolecules and cellular components.

The splenocyte proliferative response and cytokine secretion in mice after oral administration of commercial gold nanocolloid

“…Dokić et al (2012), who analyzed the influence of different fractions of AuNPs obtained by ultrasonic spray pyrolysis from gold scrap on ConA stimulated rats' splenocytes, observed that smaller and less agglomerated particles increased the synthesis of IL-2 while inhibiting the synthesis of IL-10, which resembles the effect obtained in our experiment at the medium dose of AuNPs. What is more, in studies on mouse B lymphocytes, AuNPs passed through the cytoplasmic membrane of cells, activating the cells and elevating the expression of antibodies (Sharma et al 2013). A similar outcome was observed in vivo by Dykman et al (2004), who analyzed the influence of AuNPs on the immunological response of laboratory animals (rabbits, rats and mice).…”

Effect of oral administration of commercial gold nanocolloid on peripheral blood leukocytes in mice

“…The rise observed in the percentage of B cells can easily be explained by their stimulation by nanoparticles, which has been confirmed by other research. In a line of murine B lymphocytes (CH12.LX), AuNPs passed through the cytoplasmic membrane, thus activating the cells and stimulating antibody production (Sharma et al 2013). A similar effect was achieved in vivo by Dykman et al (2004) in rabbits, rats and mice immunized with haptens or complete antigens.…”

Effects of Size, Shape, Surface Charge and Functionalization on Cytotoxicity of Gold Nanoparticles

“…58,[91][92][93] These interactions include (1) genotoxic e®ects caused by high levels of ROS and (2) proteins/ enzymes dysregulation induced by Au NP exposure. For example, Sharma and coauthors have investigated the interactions of citrate-capped Au NPs (D core ¼ 10 nm) with murine B-lymphocyte cells (CH12.LX).…”