title: Helical carbon nanotubes enhance the early immune response and inhibit macrophage-mediated phagocytosis of Pseudomonas aeruginosa.
abstract: Aerosolized or aspirated manufactured carbon nanotubes have been shown to be cytotoxic, cause pulmonary lesions, and demonstrate immunomodulatory properties. CD-1 mice were used to assess pulmonary toxicity of helical carbon nanotubes (HCNTs) and alterations of the immune response to subsequent infection by Pseudomonas aeruginosa in mice. HCNTs provoked a mild inflammatory response following either a single exposure or 2X/week for three weeks (multiple exposures) but were not significantly toxic. Administering HCNTs 2X/week for three weeks resulted in pulmonary lesions including granulomas and goblet cell hyperplasia. Mice exposed to HCNTs and subsequently infected by P. aeruginosa demonstrated an enhanced inflammatory response to P. aeruginosa and phagocytosis by alveolar macrophages was inhibited. However, clearance of P. aeruginosa was not affected. HCNT exposed mice depleted of neutrophils were more effective in clearing P. aeruginosa compared to neutrophil-depleted control mice, accompanied by an influx of macrophages. Depletion of systemic macrophages resulted in slightly inhibited bacterial clearance by HCNT treated mice. Our data indicate that pulmonary exposure to HCNTs results in lesions similar to those caused by other nanotubes and pre-exposure to HCNTs inhibit alveolar macrophage phagocytosis of P. aeruginosa. However, clearance was not affected as exposure to HCNTs primed the immune system for an enhanced inflammatory response to pulmonary infection consisting of an influx of neutrophils and macrophages.
authors: Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America.
authors: Brent E
authors: BE
authors: Walling
authors: Zhizhou
authors: Z
authors: Kuang
authors: Yonghua
authors: Y
authors: Hao
authors: David
authors: D
authors: Estrada
authors: Joshua D
authors: JD
authors: Wood
authors: Feifei
authors: F
authors: Lian
authors: Lou Ann
authors: LA
authors: Miller
authors: Amish B
authors: AB
authors: Shah
authors: Jayme L
authors: JL
authors: Jeffries
authors: Richard T
authors: RT
authors: Haasch
authors: Joseph W
authors: JW
authors: Lyding
authors: Eric
authors: E
authors: Pop
authors: Gee W
authors: GW
authors: Lau
mesh_terms: D000818:Animals; D008168:Lung / Q000276:immunology / Q000382:microbiology; D016676:Macrophages, Alveolar / Q000382:microbiology*; D051379:Mice; D037742:Nanotubes, Carbon; D009504:Neutrophils / Q000276:immunology; D010587:Phagocytosis / Q000187:drug effects*; D011550:Pseudomonas aeruginosa / Q000276:immunology*
chemical_list: D037742:Nanotubes, Carbon