The Effects of Silver Nanoparticles on RAW 264.7 Macrophages and Human Whole Blood Cell Cultures
Kim Lategan1
* and E. Pool2
1,2University of the Western Cape, South Africa
Silver nanoparticles (AgNPs) are commonly found in consumer products due to their antimicrobial properties. However, very
little is known about the effects of AgNPs on the immune system. This study evaluates the effects of AgNPs on the murine
macrophage cell line RAW 264.7 and human whole blood cell cultures (WBCs). The effects of AgNPs were assessed in the presence
or absence of a mitogen, lipopolysaccharide (LPS). The effects of AgNPs on WBCs were monitored under basal conditions, LPS or
phytohaemmagglutinin (PHA). A number of parameters were evaluated for both cultures, which included cytotoxity, biomarkers of
inflammation, cytokines of the acquired immune system and a proteome profile analysis. AgNP concentrations tested had no effect
on RAW cell viability. However, cytotoxicity of WBCs was evident at 250 μg/ml AgNP. Under basal conditions, AgNPs concentrations
≥ 62.5 μg/ml and > 25 μg/ml induced inflammation in RAW cells and WBCs respectively. Under a simulated inflammatory response
(+ LPS), 250 μg/ml AgNP inhibited the inflammatory response for both RAW and WBCs. The acquired immune cytokines IL-10
and IFNγ were both induced by 250 μg/ml AgNP in the absence of PHA. While IL-10 was partially inhibited by 250 μg/ml AgNP
in a simulated (+ PHA) acquired immune response. Proteome profiles of RAW cell supernatants show that AgNPs do in fact
modulate specific protein synthesis. Upregulated RAW cell proteins due to AgNP exposure indicate induction of proteins associated
with inflammation and wound and tissue healing. The mitogen activated WBCs proteome analysis indicates the partial inhibition of
inflammatory proteins. Monitoring those proteins in future experiments will give a better indication of the effects of AgNPs.
Biography:
Currently concluding her PhD research project in the Medical Bioscience Department at the University of the Western Cape. She is also currently
the lab manager for our Ecotoxicology/Immunotoxicology Laboratory. Her work includes investigating the in vitro effects of heavy metals and
nanoparticles on the immune system. She has previously presented work at various international conferences. These include the 16th International
Symposium on Toxicity Assessment (ISTA), 7th Society of Environmental Toxicology and Chemistry (SETAC) Africa conference and the ChinaAfrica
Water Forum.