Modulation of human alveolar macrophage properties by ozone exposure in vitro

Effects of ozone on the epithelial and inflammatory responses in the airways: role of tumor necrosis factor

We have investigated the possibility that tumor necrosis factor alpha (TNF) plays a role in the increased airway permeability and an inflammatory response following an acute ozone (O3) exposure. Male Sprague-Dawley rats were injected, intraperitoneally, with either rabbit anti-mouse antibody to TNF (anti-TNF) or preimmune rabbit serum, 2 h before a 3-h exposure to O3 or purified air. Permeability, as determined by [99mTc] diethylenetriamine pentaacetate (DTPA) transport, total protein and albumin concentrations in the bronchoalveolar lavage (BAL), and the inflammatory cell response in the BAL were assessed 10 h after the exposure was completed. The O3-exposed group that was injected with anti-TNF showed a significant decrease in permeability to DTPA in comparison to the O3- exposed group injected with preimmune rabbit serum. There was no difference between the anti-TNF group and the purified air group. In contrast, the total protein and albumin levels in the BAL were significantly greater in both of the O3-exposed groups than in the purified air group. The concentrations of protein and albumin in the anti-TNF group did, however, show an attenuating trend when compared to the preimmune O3-exposed group. The polymorphonuclear leukocytes (PMNs) in BAL of the anti-TNF group also showed an attenuating trend when compared to the preimmune O3-exposed group, but both of these O3-exposed groups were significantly greater than the purified air group. Lung sections stained with naphthol AS-D chloroacetate esterase showed an increase in the number of stained PMNs in the anti-TNF group in comparison to the preimmune O3- and air-exposed groups. These data suggest that TNF plays a role in the increase in tracheal permeability as determined by DTPA transport, while the contributing role that TNF plays in bronchoalveolar permeability and the inflammatory response seen following an acute exposure to 0.8 ppm O3 is less evident.

Combined influence of quartz dust, ozone and NO2 on chemotactic mobility, release of chemotactic factors and other cytokines by macrophages in vitro

In this study the single as well as combined effects of quartz, ozone and nitrogen dioxide (NO2) on some immunofunctions of bovine alveolar macrophages (BAM) were investigated. After incubation with 10 micrograms/ml of particles the chemotactic response of BAM is increased nonspecifically, whereas after incubation with 100 micrograms/ml of quartz chemotaxis is specifically decreased. In addition, quartz induces tumor necrosis factor alpha (TNF-alpha) and chemokines to be released dependent on the concentration. Ozone by itself is also a very potent inducer of the release of chemokines and TNF-alpha, but in combination with ozone, quartz has not more than an additive effect. NO2 alone suppresses drastically the release of TNF-alpha. The results show that quartz, ozone and NO2 alter some immunofunctions of BAM and that by combining toxic particles such as quartz with these gases, additive but not synergistic effects might be expected.

Exposure of rats to hyperoxia: alteration of lavagate parameters and macrophage function

Exposure of rats to hyperoxia (100% oxygen for 64 h) resulted in striking alterations in the properties of samples obtained by bronchoalveolar lavage. The yield of neutrophils, lymphocytes, and red blood cells was increased, while the number of harvested alveolar macrophages decreased. The acellular lavage fluid level of protein was elevated, indicating lung damage. However, acellular phospholipid levels were unchanged. The ability of alveolar macrophages to produce reactive forms of oxygen in response to zymosan was significantly decreased by oxygen exposure. This impaired function was not fully explained by a decrease in viability of these phagocytes. In contrast, stimulant-induced chemiluminescence was elevated after hyperoxia. This rise was not due to a change in cellular antioxidant levels or to a discernible increase in arachidonic acid metabolites. However, it was associated with increased cellular lipid peroxidation.