Interleukin-4 suppresses plasminogen activator inhibitor-2 formation in
stimulated human monocytes
JA Hamilton, GA Whitty, K Last, AK Royston, PH Hart and DR Burgess
Department of Medicine, University of Melbourne, Royal Melbourne Hospital,
Parkville, Australia.
Using a specific enzyme-linked immunosorbent assay, plasminogen activator
inhibitor-2 (PAI-2) was quantitated in cultures of human monocytes.
Lipopolysaccharide (LPS) increased both extracellular and cell-associated
PAI-2 levels, as well as PAI-2 mRNA measured by Northern analysis. Both the
lymphokine, interleukin-4 (IL-4) (greater than or equal to 10 pmol/L), and
the glucocorticoid, dexamethasone (100 nmol/L), inhibited PAI-2 formation
and PAI-2 mRNA induction. Another lymphokine, interferon-gamma (IFN-gamma)
(100 U/mL), as for IL-4 alone, did not stimulate PAI-2 formation; however,
in contrast to IL-4, IFN- gamma did not reverse the LPS effect but could
potentiate it. The suppression of PAI-2 formation by IL-4 and
glucocorticoid in stimulated human monocytes extends the list of monocyte
products whose synthesis can be downregulated in these cells by the two
agents. The findings could have relevance to the control by
monocytes/macrophages of connective tissue resorption, including that of
fibrin, at sites of inflammation.
Volume 80,
Issue 1,
pp. 121-125,
07/01/1992
Copyright © 1992 by The American Society of Hematology
