Interferon-α Modulates the Plasma Membrane–Cytoskeletal Complex of Human Lymphoblastoid Cells Sensitive to the Antiproliferative Action of Interferon-α

Abstract

Interferon (IFN)-induced structural changes in the plasma membrane–cytoskeletal complex were investigated in human lymphoblastoid cell lines that differed in sensitivity to the antiproliferative action of IFN-α. These cell lines have structurally indistinguishable high-affinity IFN-α receptors. By using electron spin resonance techniques, we determined the effect of IFN-α on fluidity of the plasma membrane lipid bilayer. By using the ability of cells to redistribute fluorescent anti-immunoglobulin (Ig) into caps at the cell surface, we investigated the effect of IFN-α on the mobility of the cell surface. IFN-α decreases the fluidity of the plasma membrane lipid bilayer of lymphoblastoid cells sensitive to the antiproliferative action of IFN-α. Similarly, IFN-α inhibits the anti-Ig-induced redistribution of surface immunoglobulins (capping) of IFN-sensitive cells. These effects of IFN-α occur within the first few hours after IFN-α addition to cells. However, IFN-α had no effect on membrane fluidity or anti-Ig-induced capping of lymphoblastoid cells resistant to the antiproliferative action of IFN-α.