Enhanced expression of LFA-3 on human T-cell lines and leukemic cells carrying human T-cell-leukemia virus type 1.

Previously, we studied the surface expression of LFA-1 (CD11a/CD18) and ICAM-1 (CD54) in a panel of 16 human T-cell lines and found that those carrying HTLV-1 pro-viruses expressed high levels of ICAM-1. Enhanced expression of ICAM-1 was also seen in fresh leukemic cells from ATL patients. In the present study, we systematically examined the surface expression of 19 different cell-adhesion molecules (CAMs) (the immunoglobulin superfamily, the homing receptors, the integrins, etc.) in a panel of 20 human T-cell lines (6 HTLV-1-negative lines and 14HTLV-1-positive lines). The surface expression of LFA-3 (CD58) was constantly enhanced in HTLV-1-positive T-cell lines except for MT-1, an ATL-derived cell line, which was devoid of a number of CAMs including ICAM-1. LFA-3 proteins and mRNA were found at strongly increased levels in HTLV-1-positive T-cell lines.