Assessing Dendritic Cell Activation and Phenotypic Responses to Gold Nanoparticle Treatments in Vitro

Abstract

Dendritic cells (DCs) are potent antigen-presenting cells (APCs) that orchestrate an immune response to variety of pathogens or initiate tolerance. Successful manipulation of DCs to control the immune system is a powerful approach for optimizing vaccine delivery, tissue engineering, or immunotherapeutic approaches. Biomaterials are widely used in combination products for tissue regeneration or vaccine delivery; however knowledge of how biomaterials harness DC surface receptors to induce phenotypic changes is still lacking, particularly for nanoparticles (NPs). In this study, a point of reference is established for the immunogenic effects that gold nanoparticle (AuNP) parameters have on DCs. The overall goal of this research is to use this information to engineer a specific immune response. Preliminary results indicate a concentration dependent relationship between increasing levels of AuNPs and pro- inflammatory/maturation of DCs for the bare, and Polyethylene glycol (PEG) coated nanoparticle treatment groups. AuNPs that were serum coated had the opposite trend, where an increasing concentration of AuNPs produced a tolerogenic DC phenotype. Additionally, the serum-coated AuNP treatment group showed the highest levels of tolerogenic DC expression for all treatment groups, across all concentrations. There appears to be no significant difference in the levels of induced mature DC activation between Bare, PEG-2K (short chain PEG), and PEG-5K (long chain PEG).