Koike E, Kobayashi T, Shimojo N
Department of Medicine, University of Tsukuba, Tsukuba 305-8575, Japan.
Toxicol Sci. 2001 Sep;63(1):115-24. doi: 10.1093/toxsci/63.1.115.
In this study, we investigated the effects of ozone (O3) exposure on expression of cell-surface molecules associated with antigen presentation and on accessory activity of bronchoalveolar lavage cells (BAL cells). Rats were exposed to 1 ppm O3 for 3 days. Expression of cell-surface molecules was measured by flow cytometry. Accessory activity of BAL cells was assessed by the allogeneic mixed lymphocyte reaction (MLR) and specific antigen-presenting activity. O3 exposure increased the expression of Ia, B7.1, B7.2, and CD11b/c on BAL cells. Morphological and immunological studies showed the Ia-positive cells to have monocyte-like features. Peripheral blood monocytes expressed Ia, B7.1, B7.2, and CD11b/c. The Ia expression on the monocytes was further increased by treatment of them with BAL fluid from O3-exposed rats (O3-BALF). Resident alveolar macrophages, however, did not express Ia antigen, and the Ia expression was not increased by O3-BALF. Neutrophils, which also infiltrated in response to O3 exposure, did not express Ia, B7.1, and B7.2. Therefore, infiltrating monocytes may have caused the increased expression of Ia and B7 molecules on BAL cells exposed to O3. The accessory activity of BAL cells in terms of MLR and specific antigen-presenting activity was also enhanced by O3 exposure. The present study suggests that monocytes infiltrating in response to O3 exposure caused enhancements of the expression of Ia and costimulatory molecules on and the accessory activity of BAL cells.
在本研究中，我们调查了臭氧（O₃）暴露对与抗原呈递相关的细胞表面分子表达以及对支气管肺泡灌洗细胞（BAL细胞）辅助活性的影响。将大鼠暴露于1 ppm的O₃中3天。通过流式细胞术测量细胞表面分子的表达。通过同种异体混合淋巴细胞反应（MLR）和特异性抗原呈递活性评估BAL细胞的辅助活性。O₃暴露增加了BAL细胞上Ia、B7.1、B7.2和CD11b/c的表达。形态学和免疫学研究表明，Ia阳性细胞具有单核细胞样特征。外周血单核细胞表达Ia、B7.1、B7.2和CD11b/c。用来自O₃暴露大鼠的BAL液（O₃-BALF）处理单核细胞后，其Ia表达进一步增加。然而，驻留肺泡巨噬细胞不表达Ia抗原，且O₃-BALF未增加其Ia表达。同样因O₃暴露而浸润的中性粒细胞不表达Ia、B7.1和B7.2。因此，浸润的单核细胞可能导致了暴露于O₃的BAL细胞上Ia和B7分子表达增加。O₃暴露还增强了BAL细胞在MLR和特异性抗原呈递活性方面的辅助活性。本研究表明，因O₃暴露而浸润的单核细胞导致了BAL细胞上Ia和共刺激分子表达的增强以及辅助活性的增强。
