Effects of inhaled ozone on pulmonary immune cells critical to antibacterial responses in situ
Effects of inhaled ozone on pulmonary immune cells critical to antibacterial responses in situ
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DOI：
10.1080/08958370290084520
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发表时间：
2002-06-01
影响因子：
2.1
通讯作者：
Schlesinger, RB
中科院分区：
文献类型：
--
作者：
Cohen, MD;Sisco, M;Schlesinger, RB
The goal of this study was to examine effects from repeated exposure to ozone (O-3) on immune cells involved in cell-mediated antibacterial responses in the lungs. Rats exposed to 0.1 or 0.3 ppm O-3 for 4 h/day, 5 days/wk, for 1 or 3 wk were analyzed for the ability to clear an intrapulmonary challenge with Listeria monocytogenes or had their lungs processed to obtain pulmonary alveolar macrophages (PAM) and lung-associated lymphocytes for analyses of select cell functions and surface marker expression. The results indicate that repeated inhalation exposure to O-3 affected local cell-mediated immunity (CMI) responses as evidenced by effects on clearance of Listeria. However, this modulation was not consistently dependent on exposure concentration or duration. Short-term repeat exposures had more effect on host resistance than did the more prolonged regimen, with rats exposed to 0.1 ppm O-3 most adversely impacted. Clearance patterns suggest modifications in innate resistance following 1 wk of exposure to 0.1 ppm O-3, but no similar effect following a 3-wk regimen. Exposure to 0.3 ppm O-3 appeared to affect both innate and acquired resistance after a 1-wk regimen, but mainly the former after an additional 2 wk of exposure. We conclude that these two mechanisms of resistance are differentially affected by 03 and that distinct time- and O-3 concentration-dependent adaptation phenomena evolve for each; that is, in situ adaptation to higher levels of O-3 may occur more readily with acquired than with innate/PAM-dependent resistance. A similar pattern of inconsistent effect on PAM and lung-associated lymphocytes was also evident. For example, while 3-wk exposures had a greater effect on PAM reactive oxygen intermediate ROI production, evidence for a significant effect on antibacterial activity was only notable among PAM from rats exposed for 1 wk. Among lung lymphocytes, while 3-wk exposure to 0.1 ppm O-3 led to a significant increase in CD25 expression, there was no corresponding increase in responsivity to concanavalin A (ConA); only among cells from 1-wk-exposed rats did lymphoproliferative responses increase. Though investigations of altered immune cell cytokine receptor expression/binding activity are ongoing, results herein provide further evidence to support our longstanding hypothesis that some well-documented effects of O-3 exposure on human health are quite likely linked to changes in local immune cell (i.e., PAM and lung-associated lymphocytes) functions, with the latter being related to changes in the capacities of these cells to interact with immunoregulatory cytokines.
