Role of endotoxin in tumor necrosis factor alpha expression from alveolar macrophages treated with urban air particles.
The effects of urban air and diesel particles on inflammatory cytokine gene expression, tumor necrosis factor alpha (TNF-alpha) in particular, were studied in rat alveolar macrophages. TNF-alpha, interleukin (IL)-1, IL-6, cytokine-induced neutrophil chemoattractant (CINC), and macrophage inflammatory protein (MIP)-2 gene expression and TNF-alpha secretion were increased in cells treated with 50 to 200 micrograms/mL of urban air particles in a concentration-related manner. There was no cytokine induction by diesel particles at any of the concentrations tested. Cytokine expression was not related to reactive oxygen species since antioxidants, such as catalase, TMTU, or DMSO, had no effect on TNF-alpha secretion. However, cytokine induction by urban air particles was completely prevented by polymyxin B, an antibiotic capable of neutralizing bacterial lipopolysaccharide (LPS) activities. Furthermore, LPS was detected on the urban air particles, but not on diesel particle. These results suggest that activation of cytokine gene expression and secretion in rat alveolar macrophages by urban air particles is due to the presence of endotoxin on the particles.
Dong
W
W
Environmental Immunology and Neurobiology Section, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA.
Lewtas
J
J
Luster
M I
MI
D000393:Air Pollutants / Q000633:toxicity*; D000818:Animals; D018929:Cell Culture Techniques; D003470:Culture Media / Q000493:pharmacokinetics; D004731:Endotoxins / Q000032:analysis / Q000502:physiology*; D007770:L-Lactate Dehydrogenase / Q000187:drug effects / Q000378:metabolism; D016676:Macrophages, Alveolar / Q000187:drug effects*; D016133:Polymerase Chain Reaction / Q000379:methods; D012313:RNA / Q000737:chemistry / Q000302:isolation & purification; D051381:Rats; D011916:Rats, Inbred F344; D017382:Reactive Oxygen Species / Q000502:physiology; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000378:metabolism; D001335:Vehicle Emissions / Q000633:toxicity*
D000393:Air Pollutants; D003470:Culture Media; D004731:Endotoxins; D017382:Reactive Oxygen Species; D014409:Tumor Necrosis Factor-alpha; D001335:Vehicle Emissions; D012313:RNA; D007770:L-Lactate Dehydrogenase