title: Particles from wood smoke and road traffic differently affect the innate immune system of the lung.
abstract: The effect of particles from road traffic and wood smoke on the innate immune response in the lung was studied in a lung challenge model with the intracellular bacterium Listeria monocytogenes. Female Balb/cA mice were instilled intratracheally with wood smoke particles, particles from road traffic collected during winter (studded tires used; St+), and during autumn (no studded tires; St-), or diesel exhaust particles (DEP). Simultaneously with, and 1 or 7 days after particle instillation, 10(5) bacteria were inoculated intratracheally. Bacterial numbers in the lungs and spleen 1 day after Listeria challenge were determined, as an indicator of cellular activation. In separate experiments, bronchoalveolar lavage (BAL) fluid was collected 4 h and 24 h after particle instillation. All particles tested reduced the numbers of bacteria in the lung 24 h after bacterial inoculation. When particles were given simultaneously with Listeria, the reduction was greatest for DEP, followed by St+ and St-, and least for wood smoke particles. Particle effects were no longer apparent after 7 days. Neutrophil numbers in BAL fluid were increased for all particle exposed groups. St+ and St- induced the highest levels of IL-1beta, MIP-2, MCP-1, and TNF-alpha, followed by DEP, which induced no TNF-alpha. In contrast, wood smoke particles only increased lactate dehydrogenase (LDH) activity, indicating a cytotoxic effect of these particles. In conclusion, all particles tested activated the innate immune system as determined with Listeria. However, differences in kinetics of anti-Listeria activity and levels of proinflammatory mediators point to cellular activation by different mechanisms.
authors: Norwegian Institute of Public Health, Oslo, Norway. mari.samuelsen@fhi.no
authors: Mari
authors: M
authors: Samuelsen
authors: Unni
authors: U
authors: Cecilie Nygaard
authors: Martinus
authors: M
authors: Løvik
mesh_terms: D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry / Q000166:cytology; D002452:Cell Count; D015169:Colony Count, Microbial; D005260:Female; D007113:Immunity, Innate / Q000187:drug effects*; D018836:Inflammation Mediators / Q000378:metabolism; D019570:Inhalation Exposure; D008088:Listeriosis / Q000276:immunology; D008168:Lung / Q000187:drug effects* / Q000276:immunology* / Q000382:microbiology; D051379:Mice; D008807:Mice, Inbred BALB C; D052638:Particulate Matter / Q000032:analysis / Q000633:toxicity*; D011506:Proteins / Q000032:analysis / Q000737:chemistry; D012906:Smoke / Q000009:adverse effects* / Q000032:analysis; D013154:Spleen / Q000276:immunology / Q000382:microbiology; D001335:Vehicle Emissions / Q000032:analysis / Q000633:toxicity*; D014934:Wood
chemical_list: D018836:Inflammation Mediators; D052638:Particulate Matter; D011506:Proteins; D012906:Smoke; D001335:Vehicle Emissions