Adhesion and dye transfer from HTLV-I–transformed cells to endothelial cells.

Flow cytometry analyses of cocultures of unlabeled HAECs (ECs) with calcein-labeled HTLV-I–positive cells (*HuT-102) or control cells (*Molt-4). (A) The relative height of the peak of HuT-102 or Molt-4 cells in comparison with that of HAECs is a measure of cell adhesion. The increase in the MFI of endothelial cells reflects dye transfer through gap junctions from the leukemic cells. Endothelial cells were cocultured for 1 hour with calcine-labeled tumor cells at a ratio of 1:1. (B) Histogram analysis of MFI of endothelial cells under different coculture conditions. Cells were cocultured at different endothelial cell–tumor cell ratios (EC = TC) and time intervals as indicated.