Monomeric endotoxin:protein complexes are essential for TLR4-dependent cell activation
In: Journal of Endotoxin Research, Jg. 11 (2005-04-01), S. 117-123
Online
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Zugriff:
Potent TLR4-dependent cell activation by Gram-negative bacterial endotoxin depends on sequential endotoxin—protein and protein—protein interactions with LBP, CD14, MD-2 and TLR4. LBP and CD14 combine, in an albumin-dependent fashion, to extract single endotoxin molecules from purified endotoxin aggregates (Eagg) or the bacterial outer membrane and form monomeric endotoxin:CD14 complexes that are the preferred presentation of endotoxin for transfer to MD-2. Endotoxin in endotoxin:CD14 is readily transferred to MD-2, again in an albumin-dependent manner, to form monomeric endotoxin:MD-2 complex. This monomeric endotoxin:protein complex (endotoxin:MD-2) activates TLR4 at picomolar concentrations, independently of albumin, and is, therefore, the apparent ligand in endotoxin-dependent TLR4 activation. Tetra-, penta-, and hexa-acylated forms of meningococcal endotoxin (LOS) react similarly with LBP, CD14, and MD-2 to form endotoxin:MD-2 complexes. However, tetra- and penta-acylated LOS:MD-2 complexes are less potent TLR4 agonists than hexa-acylated LOS:MD-2. This is mirrored in the reduced activity of tetra-, penta- versus hexa-acylated LOS aggregates (LOSagg) + LBP toward cells containing mCD14, MD-2, and TLR4. Therefore, changes in agonist potency of under-acylated meninigococcal LOS are determined by differences in properties of monomeric endotoxin:MD-2.
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Monomeric endotoxin:protein complexes are essential for TLR4-dependent cell activation
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Autor/in / Beteiligte Person: | Zhang, DeS. ; Teghanemt, Athmane ; Gioannini, Theresa L. ; Weiss, Jerrold ; Levis, E.N. |
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Zeitschrift: | Journal of Endotoxin Research, Jg. 11 (2005-04-01), S. 117-123 |
Veröffentlichung: | SAGE Publications, 2005 |
Medientyp: | unknown |
ISSN: | 0968-0519 (print) |
DOI: | 10.1177/09680519050110020801 |
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