OZONE CAN INCREASE THE EXPRESSION OF INTERCELLULAR-ADHESION MOLECULE-1 AND THE SYNTHESIS OF CYTOKINES BY HUMAN NASAL EPITHELIAL-CELLS

Ozone is a highly toxic and ubiquitous air pollutant that induces epithelial cell injury and airway inflammation. This study examined the effects of sublethal, near ambient ozone concentrations on the expression of intercellular adhesion molecule-1 (ICAM-1, CD54) and the synthesis of certain cytokines by human nasal epithelial cells (HNE). The cytokines studied were interleukin-1 alpha (IL-1 alpha), interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor-alpha (TNF alpha). The HNE were cultured and exposed to ozone in an environment that simulated that of the human airway. Cells were grown and exposed on microporous filters and were assayed for ICAM-1 expression in an adherent state with a laser cytometer. Dual-wavelength detection using a fluorescein-conjugated antibody to detect receptor expression and propidium iodide to count cell nuclei allowed measurement of ICAM-1 expression on individual cells, expressed as fluorescence per cell. The Il-1 alpha, IL-6, IL-8, and TNF alpha were measured in HNE culture supernatants by two-site enzyme-linked immunosorbant assays (ELISA). Exposure of the HNE to 0.50 ppm ozone