Figure 1.

Effect of IFN-γ on the proteolytic processing of MBP by lysosomal extracts. (a) Characterization of enriched microglia. Single-cell suspensions of murine glia were enriched for microglial cells in vitro and analysed for purity by CD11b expression using FACS. A purity of >95% microglia was regularly achieved. (b) Microglia were treated with IFN-γ (100 U/ml) in vitro for 24 hr (IFN-γ-treated), while control cells remained untreated. Lysosomal extracts were prepared as described, normalized for total protein, and incubated with identical amounts of recombinant MBP in vitro at pH 5·0 for 24 hr. The resulting polypeptides were resolved by RP-HPLC and detected by ultraviolet absorption at 214 nm (A₂₁₄; black line: IFN-γ-treated microglia; grey line: non-treated microglia). Intact MBP eluted at 54 min is indicated by the hatched line.