CD163 transfected CHO cells internalize ADAMTS13. Binding and uptake of Alexa Fluor 488–labeled ADAMTS13 by CD163-expressing and control CHO cells. (A) CD163-transfected CHO cells internalize ADAMTS13-AF488. (B) ADAMTS13 binding and uptake was reduced by the addition of blocking antibody EDHu-1. (C) Untransfected CHO cells stained for CD163 do not internalize ADAMTS13-AF488. Upper panels show staining for CD163–Alexa Fluor 633 (in red). Middle panels correspond to the signal obtained following internalization of ADAMTS13-AF488 (in green). The overlay of CD163 staining (red) and internalized ADAMTS13-AF488 (green) is displayed in the lower panels. ProLong Gold DAPI (blue signal) was used to stain nuclei. Scale bars are 10 μm.