Expression of PV-1 is reduced in vim^−/− mice, and its distribution changes significantly on activation with TNF-α. (A-B) Frozen sections of heart and spleen from wt and vim^−/− mice were stained for PV-1 with Meca-32 (rat anti–mouse PV-1) or negative control antibody. Vascular areas were digitally determined and the (A) fluorescence intensity values and (B) surface area of the analyzed vasculature were determined using the histogram function of the Zeiss LSM software. Two sections per mouse of 3 wild-type and 3 vim^−/− mice were analyzed. The data are shown as mean ± SEM. (C) Double-staining of nonactivated and TNF-α–activated HUVECs with anti–PV-1 and antivimentin antibodies. The arrows point to the PV-1 pool in peripheral areas of the cells, where a partial colocalization with vimentin can be seen. (D) Double staining of nonactivated and activated HUVECs with anti–PV-1 and anti–caveolin-1 antibodies. The arrows point to the peripheral areas of the cells, where PV-1 and caveolin-1 colocalize. Nuclear counterstaining was performed with 4,6-diamidino-2-phenylindole (DAPI). Scale bars represent 10 μm.