Figure 4.

IL-4 induces the expression of Ym1 in cultured microglial cells. A–C, Microglial cells cultured from adult mice were examined for expression of Ym1 by flow cytometry in medium alone (A) or after incubation with IL-4 (200 U/ml) (B) or IFN-γ (150 U/ml) in combination with LPS (100 ng/ml) (C) for 24 h. The solid line represents staining with anti-Ym1, and the dotted line represents background staining using rabbit serum (1:1000). The horizontal bar indicates positive staining, and the number above the bar is the percentage positive. D, IL-4 mRNA levels were measured in ex vivo isolated (open bar) and in vitro cultured (filled bar) microglial cells by real-time RT-PCR as for Figure 1. A–D, One representative experiment of three is shown.