Inducing Activity of Respiratory Syncytial Virus on the Production of Macrophage Inflammatory Protein-2 in Murine Macrophages and Airway-lining Cells

We investigated the macrophage inflammatory protein-2 (MIP-2)-producing activity of respiratory syncytial virus (RSV) in a murine macrophage cell line, RAW 264.7 cells, and airway-lining cells by the application of recently developed enzyme-linked immunosorbent assay (ELISA) system. The production of MIP-2 increased significantly in both cells by the infections of RSV in a dose-dependent manner. In addition to ELISA, MIP-2 production could be detected in RSV-infected airway-lining cells by immunocytochemical study. The heat-inactivated virus also enhanced MIP-2 production to comparable levels of the infections with the active virus. Time-related production showed a trend for a biphasic pattern, suggesting that this phenomenon might be due to the combined effects of the direct MIP-2-inducing activity of RSV and an indirect one via the initial production of other cytokines inducible for MIP-2 production. These data indicate that RSV, either in active or inactive form, has the potential to stimulate MIP-2 production in a cultured macrophage cell line and airway-lining cells