DIFFERENTIAL ADHERENCE OF THE HUMAN MONOCYTE SUBSETS 27E10 AND RM3 1 TO CYTOKINE-TREATED OR GLUCOCORTICOID-TREATED ENDOTHELIAL-CELLS/

Monocyte-endothelial interactions are of particular importance in the regulation of inflammation. The aim of the present study was to invest igate the adhesion of functional different monocyte subsets to human u mbilical vein endothelial cells treated with various cytokines or a gl ucocorticoid. The adherence of monocyte subset 27E10, which is associa ted with inflammatory processes, increased after endothelial activatio n with interleukin-1 beta (IL-1 beta), interferon-gamma (IFN gamma), t umor necrosis factor-alpha (TNF alpha), and the glucocorticoid prednyl idene (Pred). The adherence at IFN gamma-treated endothelial cells was strong after a coculture duration of 10 min with a slight increase up to 60 min. The peak value after TNF alpha stimulation was reached aft er 15 min, thereafter quickly decreasing. IL-1 and Pred treatment caus ed a maximal adherence between 15 and 30 min followed by a slow decrea se. TNF alpha and particularly interleukin-6 (IL-6) enhanced the endot helial adhesion of the monocyte subtype RM3/1, which is associated wit h the downregulation of inflammation. The maximal adherence was found after 15 and 30 min of coculture, respectively. The results show that, through modulation of the adhesive properties of endothelial cells, c ytokines and glucocorticoids affect the adherence of monocyte subsets differently. They also suggest that IL-6 plays a role in the downregul ation of acute inflammation.