Iron oxide nanoparticles suppressed T helper 1 cell-mediated immunity in a murine model of delayed-type hypersensitivity.
BACKGROUND
It was recently reported that iron oxide nanoparticles attenuated antigen-specific humoral responses and T cell cytokine expression in ovalbumin-sensitized mice. It is presently unclear whether iron oxide nanoparticles influence T helper 1 cell-mediated immunity. The present study aimed to investigate the effect of iron oxide nanoparticles on delayed-type hypersensitivity (DTH), whose pathophysiology requires the participation of T helper 1 cells and macrophages.


METHODS
DTH was elicited by a subcutaneous challenge with ovalbumin to the footpads of mice sensitized with ovalbumin. Iron oxide nanoparticles (0.2-10 mg iron/kg) were administered intravenously 1 hour prior to ovalbumin sensitization. Local inflammatory responses were examined by footpad swelling and histological analysis. The expression of cytokines by splenocytes was measured by enzyme-linked immunosorbent assay.


RESULTS
Administration of iron oxide nanoparticles, in a dose-dependent fashion, significantly attenuated inflammatory reactions associated with DTH, including the footpad swelling, the infiltration of T cells and macrophages, and the expression of interferon-γ, interleukin-6, and tumor necrosis factor-α in the inflammatory site. Iron oxide nanoparticles also demonstrated a suppressive effect on ovalbumin-stimulated production of interferon-γ by splenocytes and the phagocytic activity of splenic CD11b(+) cells.


CONCLUSIONS
These results demonstrated that a single dose of iron oxide nanoparticles attenuated DTH reactions by suppressing the infiltration and functional activity of T helper 1 cells and macrophages in response to antigen stimulation.
Department and Graduate Institute of Veterinary Medicine, School of Veterinary Medicine, National Taiwan University, Taipei.
Chien-Chang
CC
Shen
Hong-Jen
HJ
Liang
Chia-Chi
CC
Wang
Mei-Hsiu
MH
Liao
Tong-Rong
TR
Jan
D000818:Animals; D039481:CD11b Antigen / Q000276:immunology; D016207:Cytokines / Q000276:immunology; D004195:Disease Models, Animal; D005290:Ferric Compounds / Q000737:chemistry / Q000494:pharmacology*; D006968:Hypersensitivity, Delayed / Q000188:drug therapy* / Q000276:immunology*; D007150:Immunohistochemistry; D008264:Macrophages / Q000187:drug effects / Q000276:immunology; D058185:Magnetite Nanoparticles / Q000008:administration & dosage* / Q000737:chemistry; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010047:Ovalbumin / Q000276:immunology; D010587:Phagocytosis / Q000187:drug effects; D013154:Spleen / Q000166:cytology; D006377:T-Lymphocytes, Helper-Inducer / Q000187:drug effects* / Q000276:immunology* / Q000378:metabolism
D039481:CD11b Antigen; D016207:Cytokines; D005290:Ferric Compounds; D058185:Magnetite Nanoparticles; C000499:ferric oxide; D010047:Ovalbumin