Previous Article | Next Article ![]()
Infection and Immunity, December 1998, p. 5842-5847, Vol. 66, No. 12
Department of Physiology and
Biophysics,1 and
The Price Institute of
Surgical Research, Department of Surgery,2
University of Louisville, School of Medicine, Louisville, Kentucky
Received 15 May 1998/Returned for modification 26 June
1998/Accepted 28 September 1998
Activated polymorphonuclear leukocytes release heparin-binding
protein (HBP; also known as CAP37 or azurocidin) from azurophilic granules. HBP is a strong chemoattractant for monocytes that also prolongs monocyte survival and potentiates endotoxin
(lipopolysaccharide [LPS])-induced production of tumor necrosis
factor alpha (TNF-
0019-9567/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.
Modulation of Lipopolysaccharide-Induced Monocyte
Activation by Heparin-Binding Protein and Fucoidan
). We investigated the binding of fluorescein
isothiocyanate-conjugated HBP to human monocytes in the presence of
EDTA and the polysaccharide fucoidan. EDTA, which chelates divalent
cations, has been widely used to study the role of divalent cations in
receptor-ligand interactions or enzyme activity. Fucoidan has been used
to inhibit the binding of various ligands to scavenger receptors or
selectins. Scavenger receptors are multiligand receptors that mediate
endocytosis of proteases, protease-inhibitor complexes, lipoproteins,
and LPS-lipid A. Fucoidan also interferes with leukocyte rolling by binding to L-selectins (expressed on leukocytes) and P-selectins (expressed on platelets and endothelium). We demonstrate that the
binding of the neutrophil-derived protein HBP to monocytes is inhibited
in the presence of EDTA and fucoidan. In addition, fucoidan and EDTA
abrogate the enhancing effect of HBP on LPS-induced TNF-
production.
These data provide supporting evidence that HBP binds to a receptor
expressed on monocytes. This receptor is dependent on divalent cations
and is possibly related to the scavenger receptor. Furthermore, we
demonstrate that fucoidan, by itself, stimulates TNF-
release from
isolated monocytes in a CD14-independent fashion. This is an important
finding for the interpretation of results from studies that use
fucoidan to "block" either scavenger receptors or L- or
P-selectins.
*
Corresponding author. Mailing address: c/o M. Abby,
Editorial Office, Department of Surgery, University of Louisville,
Louisville, KY 40292. Phone: (502) 852-5442. Fax: (502) 852-8915. E-mail: mheinzelmann{at}bluewin.ch.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»