EFFECT OF INTERFERON-GAMMA ON MEMBRANE CONFORMATION IN THE MACROPHAGE-LIKE CELL-LINE P388D

Interferon-gamma (IFN-gamma) specifically induced the uptake of the un saturated fatty acid [C-14]linoleic acid into membrane phospholipids o f the murine macrophage-like P388D cell lineage, but did not alter the incorporation of the saturated fatty acid [C-14]stearic acid. Spin la bel ESR spectroscopy was used to examine any effects of these IFN-gamm a-induced changes on membrane fluidity and the results revealed signif icant increases in plasma membrane fluidity. This alteration in membra ne fluidity may have important consequences in the dynamic properties of cellular physiochemical interactions and some of the stimulatory ef fects of IFN-gamma on macrophages might be attributed to its effects o n the plasma membrane composition.