Adhesion of peripheral ATL cells to IL-1–activated HUVECs and purified ICAM-1. A proportion of ATL cells were transfected with sense or antisense oligonucleotides of MIP-1β and MIP-1α and preincubated for 24 hours at 37°C. Another group of ATL cells were pretreated with a mixture of anti–MIP-1α and anti–MIP-1β Abs for 4 hours at 37°C. Adhesion assay of ATL cells to purified ICAM-1 (a) or IL-1–activated HUVECs (b) was performed in the presence or absence of indicated adhesion-blocking MoAbs (10 μg/mL). Data are expressed as the mean percentage of bound cells from a representative experiment of 4 patients.