Exposure of Cultured Microglial Cells to Interferon-gamma

Abstract

The reactions of a microglial cell population to exposure to interferon-gamma (IFN-γ) were studied in primary cultures of mixed glial cells from the brains of newborn rats. One week after seeding, the cells were exposed to 200U/ml of IFN-γ for 24 and 48 hours. After exposure to IFN-γ for 48 hours, a third of the cultures were exposed to phorbol myristate acetate (PMA) for 90 minutes. Transformation of the microglial cells in response to this treatment was observed by using a light microscope. On time-lapse film, an increase in the mobility of the cells and an increase in the number of amoeba-like microglia were among the most evident changes induced by IFN-γ. These changes became more pronounced when the exposure time was increased. The addition of PMA significantly enhanced this process. After exposure to IFN-γ for 48 hours, expression of the MHC class II antigen was observed. The interleukin-1β content of the cells was increased in the cultures after 24 hours, but declined after further exposure.