Effect of HTLV-I–positive cells or cell supernatant on Matrigel-induced tube formation of endothelial cells in vitro.

Endothelial cells (ECs) were plated on growth factor-reduced Matrigel in the presence of culture medium, HuT-102 cells, HuT-102 cellfree supernatant, and CEM cellfree supernatant. Plates were photographed using light and fluorescence microscopy (magnification × 20) and Hoechst nuclear staining.