title: Amorphous silica nanoparticles enhance cross-presentation in murine dendritic cells.
abstract: Nanomaterials (NMs) exhibit unique physicochemical properties and innovative functions, and they are increasingly being used in a wide variety of fields. Ensuring the safety of NMs is now an urgent task. Recently, we reported that amorphous silica nanoparticles (nSPs), one of the most widely used NMs, enhance antigen-specific cellular immune responses and may therefore aggravate immune diseases. Thus, to ensure the design of safer nSPs, investigations into the effect of nSPs on antigen presentation in dendritic cells, which are central orchestrators of the adaptive immune response, are now needed. Here, we show that nSPs with diameters of 70 and 100 nm enhanced exogenous antigen entry into the cytosol from endosomes and induced cross-presentation, whereas submicron-sized silica particles (>100 nm) did not. Furthermore, we show that surface modification of nSPs suppressed cross-presentation. Although further studies are required to investigate whether surface-modified nSPs suppress immune-modulating effects in vivo, the current results indicate that appropriate regulation of the characteristics of nSPs, such as size and surface properties, will be critical for the design of safer nSPs.
authors.affiliation: Laboratory of Toxicology and Safety Science, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Toshiro
authors.initials: T
authors.lastname: Hirai
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Yoshioka
authors.forename: Hideki
authors.initials: H
authors.lastname: Takahashi
authors.forename: Ko-ichi
authors.initials: K
authors.lastname: Ichihashi
authors.forename: Tokuyuki
authors.initials: T
authors.lastname: Yoshida
authors.forename: Saeko
authors.initials: S
authors.lastname: Tochigi
authors.forename: Kazuya
authors.initials: K
authors.lastname: Nagano
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Abe
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Kamada
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Tsunoda
authors.forename: Hiromi
authors.initials: H
authors.lastname: Nabeshi
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Yoshikawa
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Tsutsumi
mesh_terms: D000818:Animals; D017951:Antigen Presentation / Q000187:drug effects*; D002478:Cells, Cultured; D045142:Cross-Priming / Q000187:drug effects*; D003713:Dendritic Cells / Q000187:drug effects* / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D053758:Nanoparticles / Q000009:adverse effects*; D010316:Particle Size; D012822:Silicon Dioxide / Q000009:adverse effects*
chemical_list: D012822:Silicon Dioxide