Colocalization of TM4SF molecules with c-kit.

(A) MO7e cells were treated with or without 50 ng/mL SLF for 60 minutes at 37°C. Cell surface TM4SF molecules or CD50 were cross-linked first with primary mAbs and then with FITC-conjugated antimouse antibody and allowed to cap at 37°C. The cells were then stained with biotin-labeled anti–c-kit or -CD31 mAbs and TRITC-conjugated streptavidin. Fluorescence intensities from FITC (left column) and TRITC (right column) were separately determined by a confocal laser scanning microscopy. These are the representative results from 3 separate experiments. (B) Cord blood CD34⁺ cells were incubated with IL-6, TPO, and Flt3 ligand for 3 days. The cells were treated with or without 50 ng/mL SLF for 60 minutes at 37°C. After capping induction with FITC-conjugated anti-CD81 mAb and purified antimouse antibody, the cells were stained with biotin-labeled anti–c-kit mAb and TRITC-conjugated streptavidin, and visualized by confocal laser scanning microscopy. These are the representative results from 2 separate experiments.