Differentiation-induced transmigration of HL60 cells across activated HUVEC monolayer involves E-selectin-dependent mechanism.

The leukocyte-endothelial adhesive interaction is one of the key mechanisms during inflammation. The human promyelocytic cell line HL60 has been used in a number of studies to characterize leukocyte-endothelial interactions, especially selectin-mediated adhesion. HL60 also has been used in studies to characterize the myeloid cell function during differentiation. In this study, we investigated the adhesive interactions of HL60 to vascular endothelium, either in its undifferentiated state or after dimethylsulfoxide-induced granulocytic differentiation. Granulocytic differentiation of HL60 cells significantly enhanced their transmigration across cytokine-activated (IL-1 beta 10 U/ml, 4 h) HUVEC monolayer. Interestingly, this enhanced transmigration of differentiated HL60 cells was inhibited by pretreatment of the monolayers with anti-E-selectin mAb as well as anti-ICAM-1 mAb or anti-VE-cadherin mAb, suggesting a potential role for E-selectin in transendothelial migration. Further study of this enhanced transmigration mechanism may elucidate the regulation of selectin-mediated leukocyte-endothelial interactions.