FIG. 1.

HTLV-1-infected lymphocyte adhesion to and migration through brain endothelial cells. (A) Adhesion and transendothelial migration of HTLV-1-infected and control lymphocytes through GPNT cell monolayers. Each point represents the mean obtained from a minimum of six separate wells or three separate filters from one experiment representative of three. Results are expressed as the fractional T-lymphocyte adhesion to or migration through endothelial cells. (B) Expression of LFA-1 and VLA-4 by HTLV-1-infected and control lymphocytes using FACScan analysis. (C) ELISA determination of ICAM-1 and VCAM-1 expression by GPNT cells following stimulation with 100 U of TNF-α and IL-1β per ml for 24 h. Results are from six separate wells from one representative experiment. O.D., optical density. (D) Effect of monoclonal anti-LFA-1 and anti-VLA-4 antibodies on lymphocyte adhesion to GPNT cells. The concentrations of antibodies used are those indicated by the manufacturer as inhibiting the adhesion of different cell types (10 μg/ml). Results are for six separate wells from one representative experiment.