The effects of interferon on glial cells.

The effects of a partially purified rat interferon (RIF) on cell lines cloned from a chemically induced rat glioma (A15A5) and normal rat brain (ARBOC9) were investigated. Interferon treatment reduced the rate of exponential growth and saturation density of both cell lines, but induced contrasting morphological changes. A15A5 cells became bipolar, developed longer processes and produced less extracellular fibronectin, whereas ARBOC9 cells became enlarged, showed increased multinuclearity, expressed more fibronectin and contained actin-like cytoplasmic filaments. These findings demonstrate that RIF has an antiproliferative activity in vitro on both neoplastic and non-neoplastic astrocytes, but that morphological and immunocytochemical responses differ.