Figure 1:

in vitro inhibitory effects of SKI-O-592 and -703 on Syk in B cells and monocytes. Ramos cells (A), human primary monocytes (B), and THP cells (C) were pretreated with inhibitors at the indicated concentrations and stimulated with anti-human IgM (A) and human IgG (B and C). The cells were then lysed and assayed by immunoblotting methods. The relative intensities of protein phosphorylation levels were quantitated with reference to each lane of β-actin control bands. (D) Ramos cells, human primary monocytes, and THP cells were treated as in A–C for 24 h and levels of phosphorylated Syk (p-Syk) were measured by ELISA. (E) Mouse primary B cells were stimulated with anti-IgM mAb for 60 min in the presence or absence of SKI-O-703 and assayed for p-Syk by FACS. A representative FACS profile and data on the dose-response of mean fluorescence intensity (MFI) are shown. The data are representative of two independent experiments.