Effect of IFN
on survival of O2A progenitors and oligodendrocytes.
(A) Number of viable O2A progenitor cells or oligodendrocytes as a function of a 48-hr exposure to control buffer or IFNγ (γ). p < 0.01 for all comparisons. (B) O2A progenitor cell (♦) and oligodendrocyte (∇) survival as a function of IFNγ concentration. (C) Micrographs of oligodendrocytes treated for four days with control buffer or IFNγ. Cells were stained for surface galactosylcerebroside with the O1 antibody. Viable oligodendrocytes with characteristic sheet-like processes (arrows) are shown in the control (c) panel. Late morphologic changes of cell death including degradation of processes into vacuoles are noted in the cultures treated with IFNγ (γ) for 4 days (arrowheads). (D) Comparison of the effects of IFNγ and TNFα on oligodendrocyte survival.