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 epit helial cell injury and airway inflammation. This study examined the ef fects of sublethal, near ambient ozone concentrations on the expressio n of intercellular adhesion molecule-1 (ICAM-1, CD54) and the synthesi s of certain cytokines by human nasal epithelial cells (HNE). The cyto kines 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 si mulated that of the human airway. Cells were grown and exposed on micr oporous filters and were assayed for ICAM-1 expression in an adherent state with a laser cytometer. Dual-wavelength detection using a fluore scein-conjugated antibody to detect receptor expression and propidium iodide to count cell nuclei allowed measurement of ICAM-1 expression o n 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 th e HNE to 0.50 ppm ozone