FIG. 8.

MHC class I but not class II expression by microglia is reduced in the absence of IFN-I signaling. Cells isolated from the CNS were analyzed for MHC class I (H-2D^b) and class II (I-A^b) expression at the indicated times p.i. (A and C) Histograms revealing kinetics of class I (A) or class II (C) expression are gated on CD45^low microglia (left panels) and CD45^high, F4/80⁺ bone marrow-derived infiltrating macrophages (right panels, MΦ). MHC class I or class II expression by wt cells is indicated by gray lines, and that by IFNAR^−/− cells is indicated by black lines. Isotype control MAb staining is indicated by filled histograms. Numbers in the right corner of each plot in panel A indicate the mean fluorescence intensity of H-2D^b staining. Plots are representative of three independent experiments. (B and D) The proportion of microglia expressing class I (B) or class II (D) at the indicated days p.i. Data represent the means of three experiments ± standard errors of the means.