Endotoxin contamination contributes to the in vitro cytokine-inducing activity of osteopontin preparations.
Recently, both native and recombinant preparations of human osteopontin (OPN) have been shown to be able to induce the production of several proinflammatory cytokines in human peripheral blood mononuclear cells (PBMCs) or purified monocytes. In the present study, we found that commercially available native and recombinant OPNs contain variable amounts of endotoxin (LPS) and that removal of endotoxin by polymyxin B-agarose column abrogated their cytokine-inducing activity. These results suggest the questionable evidence of the ability of OPN to induce several cytokines in human PBMCs and draw attention to the exquisite sensitivity of PBMCs/monocytes to endotoxin contaminants.
Konno
Satoshi
S
Johns Hopkins Asthma and Allergy Center, Baltimore, MD 21224, USA.
Hoshi
Takuya
T
Taira
Toshio
T
Plunkett
Beverly
B
Huang
Shau-Ku
SK
D000818:Animals; D016207:Cytokines / Q000096:biosynthesis*; D004340:Drug Contamination; D004731:Endotoxins / Q000302:isolation & purification / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D018836:Inflammation Mediators / Q000378:metabolism; D018664:Interleukin-12 / Q000096:biosynthesis; D053762:Interleukin-12 Subunit p40; D015850:Interleukin-6 / Q000096:biosynthesis; D016209:Interleukin-8 / Q000096:biosynthesis; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000276:immunology; D008070:Lipopolysaccharides / Q000302:isolation & purification / Q000494:pharmacology; D051379:Mice; D053495:Osteopontin; D021122:Protein Subunits / Q000096:biosynthesis; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000494:pharmacology; D012795:Sialoglycoproteins / Q000302:isolation & purification / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
D016207:Cytokines; D004731:Endotoxins; D018836:Inflammation Mediators; D053762:Interleukin-12 Subunit p40; D015850:Interleukin-6; D016209:Interleukin-8; D008070:Lipopolysaccharides; D021122:Protein Subunits; D011994:Recombinant Proteins; C506895:SPP1 protein, human; D012795:Sialoglycoproteins; C506896:Spp1 protein, mouse; D014409:Tumor Necrosis Factor-alpha; D053495:Osteopontin; D018664:Interleukin-12