ASSOCIATION BETWEEN EXPRESSION OF INTERCELLULAR-ADHESION MOLECULE-1 AND INTEGRATION OF HUMAN T-CELL-LEUKEMIA VIRUS TYPE-1 IN ADULT T-CELL LEUKEMIA-CELLS

It is known that the expression levels of intercellular adhesion molec ule-1 (ICAM-1) in adult T cell leukemia(ATL) cells are high, whereas t hose in T-lymphoid cells are not, in order to investigate the factors that influence the induction of ICAM-1 molecules, Northern blot analys is to measure the expression level of ICAM-1 mRNAs and Southern blot h ybridization to analyze the integration of human T-cell-leukemia virus type 1 (HTLV-1) provirus were done. The levels of ICAM-1 mRNA express ion of ATL cells were generally higher than those of T-lymphoid cells. However, ILT-mat cells and ATL16T(-) cells, although they were ATL ce lls, showed rather low surface ICAM-1 expression and ICAM-1 mRNA expre ssion. Southern blot hybridization showed that only two and four bands were found in ILT-mat and ATL16T(-) cells, respectively, whereas > 10 bands were detected in other ATL cells. These results suggest that mo noclonal integration of HTLV-1 provirus to the genome of T cell, espec ially the number of integration sites, is one of the factors for induc tion of ICAM-1 molecules. (C) 1997 Wiley-Liss, Inc.