Endotoxin contamination contributes to the in vitro cytokine-inducing activity of osteopontin preparations

Satoshi Konno, Takuya Hoshi, Toshio Taira, Beverly Plunkett, Shau Ku Huang

Research output: Contribution to journalArticle

13 Citations (Scopus)


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.

Original languageEnglish
Pages (from-to)277-282
Number of pages6
JournalJournal of Interferon and Cytokine Research
Issue number5
Publication statusPublished - May 1 2005
Externally publishedYes


ASJC Scopus subject areas

  • Immunology
  • Cell Biology
  • Virology

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