Endotoxin-free heat-shock protein 70 fails to induce APC activation.
Previous work has suggested that the peptide-carrier, heat-shock protein (hsp)70, could directly activate APC. Here we show that this ability is related to endotoxin contamination of the human rhsp70 produced in Escherichia coli. Hence, the ability of 1-3 microg/ml of rhsp70 to induce the maturation of human monocyte-derived DC is abrogated in the presence of the LPS-antagonist polymyxin B or when the rhsp70 contains less than 60 IU/mg endotoxin. Such a level of contamination of the rhsp70 is, however, sufficient - in the presence of soluble rCD14, the LPS co-receptor - to induce cytokine secretion from monocytes and DC, despite the presence of polymyxin B. However, when endotoxin contamination is below 10 IU/mg, rhsp70 does not induce cytokine secretion - even in the presence of soluble rCD14 - or activate p38 mitogen-activated protein kinase signaling pathways, thus showing that an "endotoxin free" hsp70 does not activate APC.
Bausinger
Huguette
H
1INSERM, Equipe Propre 99-08, Etablissement Français du Sang-Alsace, Strasbourg, France.
Lipsker
Dan
D
Ziylan
Umit
U
Manié
Serge
S
Briand
Jean-Paul
JP
Cazenave
Jean-Pierre
JP
Muller
Sylviane
S
Haeuw
Jean-François
JF
Ravanat
Catherine
C
de la Salle
Henri
H
Hanau
Daniel
D
D000595:Amino Acid Sequence; D000938:Antigen-Presenting Cells / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology / Q000276:immunology*; D002454:Cell Differentiation / Q000187:drug effects; D016207:Cytokines / Q000096:biosynthesis; D003713:Dendritic Cells / Q000166:cytology / Q000187:drug effects / Q000201:enzymology / Q000276:immunology; D004340:Drug Contamination; D004731:Endotoxins / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000302:isolation & purification / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D008969:Molecular Sequence Data; D009000:Monocytes / Q000166:cytology / Q000187:drug effects / Q000201:enzymology / Q000276:immunology; D011112:Polymyxin B / Q000494:pharmacology; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects; D048051:p38 Mitogen-Activated Protein Kinases
D016207:Cytokines; D004731:Endotoxins; D018840:HSP70 Heat-Shock Proteins; D011994:Recombinant Proteins; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D011112:Polymyxin B