Leukotriene B4-induced hyperadhesiveness of endothelial cells for neutrophils: relation to CD54

Leukotriene B4 (LTB4) induced an in vitro transient state of hyperadhesiveness in cultured human umbilical vein endothelial cells (HUVEC), leading to a 2.2-fold increase in the binding of neutrophil granulocytes (PMN), which was less than that conferred by platelet activating factor (PAF) though more than thrombin did (3.4- or 2.0-fold increases, respectively). This study concerns the role of the adhesive molecules CD18 and CD54 for the LTB4- (as well as thrombin- and PAF-) induced endothelial hyperadhesiveness. The MoAbs 60.3 (to the CD18 molecule on PMN) and 84H10 (to one epitope of CD54 on the HUVEC) blocked the adherence of PMN to LTB4-treated HUVEC, whereas MoAb LB-2 (directed at another CD54 epitope) failed to do so. MoAb 84H10 blocked 43% of the thrombin-induced hyperadhesiveness, whereas the PAF response was unaffected. Thus, LTB4-induced HUVEC hyperadhesiveness may therefore be related to a specific domain on the CD54 (or on an antigenically related molecule) as well as being dependent on CD18, whereas the involvement of CD54 was much less or non-existent for the thrombin and PAF responses, respectively.