LPS induces CD40 expression in primary macrophages and microglia. Human primary macrophages (A) or murine primary microglia (B) were treated with LPS (10 ng/mL) for 36 hours, and then cells were subjected to FACS analysis for CD40 protein expression. ISO indicates isotype antibody. In addition, cells were treated with LPS for 4 and 8 hours, then total RNA was isolated and analyzed by RPA for CD40 and GAPDH mRNA expression. The cell numbers are mapped on the y-axis. Representative of 2 experiments.