Combined exposure to carbon nanotubes and bacteria enhances pulmonary inflammation and infectivity.
Murray-AR; Kisin-E; Fabisiak-JP; Roberts-JR; Antonini-JM; Kommineni-C; Reynolds-J; Barchowsky-A; Castranova-V; Kagan-V; Shvedova-AA
Toxicologist 2008 Mar; 102(1):306
Carbon nanotubes (CNT) - with their applications in industry and medicine - may lead to new risks to human health. CNTs induce a robust pulmonary inflammation and oxidative stress in rodents. Realistic exposures to CNT may occur in conjunction with other pathogenic impacts (microbial infections) and trigger enhanced responses. We evaluated interactions between pharyngeal aspiration of single walled CNT (SWCNT) and bacterial pulmonary infection of C57BL/6 mice with Listeria monocytogenes (LM). Mice were first given SWCNT (0, 10 and 40 microg/mouse) and 3 days later exposed to LM (103 bacteria/mouse). Combined exposure to SWCNT/LM amplified lung inflammation and fibrosis. Despite this robust inflammatory response, SWCNT pre-exposure significantly decreased the pulmonary clearance of LM measured 3 - 7 days after microbial infection vs PBS/LM treated mice. Failure of SWCNT-exposed mice to clear LM led to a continued elevation in nearly all major chemokines and acute phase cytokines into the later course of infection. In SWCNT/LM exposed mice, BAL PMNs, AMs and lymphocytes, as well as LDH levels, were increased compared to mice exposed to SWCNT or LM alone. Increased levels of collagen deposition were found in the lung of mice exposed to SWCNT/LM vs SWCNT or LM alone. Combined exposure to SWCNT/LM caused persistent changes in breathing rate patterns indicative of detrimental decline in the lung function. In conclusion, enhanced acute inflammation and pulmonary injury with delayed pulmonary bacterial clearance after SWCNT exposure may lead to increased susceptibility to lung infection in exposed populations.
Particulates; Particulate-dust; Cell-biology; Biological-factors; Biological-monitoring; Biological-effects; Respiratory-hypersensitivity; Respiratory-irritants; Respiratory-system-disorders; Pulmonary-disorders; Pulmonary-system-disorders; Pulmonary-system; Laboratory-animals; Breathing; Immune-system-disorders; Microbiology; Bacteria; Bacterial-dusts; Bacterial-infections; Nanotechnology
The Toxicologist. Society of Toxicology 47th Annual Meeting and ToxExpo, March 16-20, 2008, Seattle, Washington