High-molecular-weight kininogen fragments stimulate the secretion of cytokines and chemokines through uPAR, Mac-1, and gC1qR in monocytes.
OBJECTIVE
Plasma high-molecular-weight kininogen (HK) is cleaved in inflammatory diseases by kallikrein to HKa with release of bradykinin (BK). We postulated a direct link between HKa and cytokine/chemokine release.


RESULTS
HKa, but not BK, releases cytokines tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, IL-6, and chemokines IL-8 and MCP-1 from isolated human mononuclear cells. At a concentration of 600 nM, glutathione-S-transferase (GST) fusion proteins of kininogen domain 3 (D3), a fragment of domain 3, E7P (aaG255-Q292), HK domain 5 (D5), the D5 recombinant peptides HG (aa K420-D474) and HGK (aa H475-S626) stimulated secretion of IL-1beta from mononuclear cells. Monoclonal antibodies (MAbs) specific for D5 or specific for D3 blocked release of IL-1beta by HKa, supporting the importance of both domains. Antibodies to HK receptors on leukocytes including Mac-1, LFA-1, uPAR, and C1qR inhibited IL-1beta secretion induced by tKa 98%, 89%, 85%, and 62%, respectively. Fractionation of mononuclear cells identified the responsible cell, a blood monocyte. Inhibitors of signaling pathways NFkB, JNK, and p38 but not extracellular signal-regulated kinase (ERK) decreased cytokine release from mononuclear cells. HKa increased the synthesis of IL-1beta as deduced by an increase of IL-1beta mRNA at 1 to 2 hours.


CONCLUSIONS
HKa domains 3 and 5 may contribute to the pathogenesis of inflammatory diseases by releasing IL-1beta from human monocytes using intracellular signaling pathways initiated by uPAR, beta2 integrins and gC1qR.
Khan
Mohammad M
MM
The Sol Sherry Thrombosis Research Center, Temple University School of Medicine, 3400 N. Broad St, Philadelphia, PA 19140, USA.
Bradford
Harlan N
HN
Isordia-Salas
Irma
I
Liu
Yuchuan
Y
Wu
Yi
Y
Espinola
Ricardo G
RG
Ghebrehiwet
Berhane
B
Colman
Robert W
RW
D000911:Antibodies, Monoclonal / Q000494:pharmacology; D040881:CD11a Antigen / Q000276:immunology; D018925:Chemokines / Q000378:metabolism*; D016207:Cytokines / Q000378:metabolism*; D006801:Humans; D007375:Interleukin-1 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D019679:Kininogen, High-Molecular-Weight / Q000276:immunology / Q000378:metabolism / Q000494:pharmacology*; D016177:Macrophage-1 Antigen / Q000276:immunology / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000276:immunology / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000502:physiology; D009000:Monocytes / Q000378:metabolism*; D016328:NF-kappa B / Q000502:physiology; D009994:Osmolar Concentration; D010446:Peptide Fragments / Q000276:immunology / Q000378:metabolism / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000276:immunology / Q000378:metabolism*; D011951:Receptors, Complement / Q000276:immunology / Q000378:metabolism*; D055293:Receptors, Urokinase Plasminogen Activator; D013997:Time Factors
D000911:Antibodies, Monoclonal; D040881:CD11a Antigen; D018925:Chemokines; D016207:Cytokines; D007375:Interleukin-1; D019679:Kininogen, High-Molecular-Weight; D016177:Macrophage-1 Antigen; D008562:Membrane Glycoproteins; D016328:NF-kappa B; C524898:PLAUR protein, human; D010446:Peptide Fragments; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D011951:Receptors, Complement; D055293:Receptors, Urokinase Plasminogen Activator; C032402:complement 1q receptor; D020928:Mitogen-Activated Protein Kinases