Tissue factor generation by human mononuclear cells: Effects of endotoxin and dissociation of tissue factor generation from mitogenic response

Frederick R. Rickles, Jack Levin, John A. Hardin, Charles F. Barr, Marcel E. Conrad

Research output: Contribution to journalArticle

61 Scopus citations

Abstract

The effects of the presence of endotoxin in a mononuclear cell culture system have been assessed. Endotoxin was shown to be mitogenic for human peripheral blood lymphocytes and capable of stimulating the generation of tissue factor. Concentrations of endotoxin, found to contaminate many commercial mitogens and antigens, activated mononuclear cells in a time-dependent manner. Generation of tissue factor was detected in cultures harvested from 2 to 72 hours following stimulation with endotoxin. Dose-response curves relating concentrations of endotoxin to mononuclear cell stimulation were determined; as little as 0.0001 μg/ml. of E. coli endotoxin was capable of stimulating the generation of tissue factor in the cell cultures. The mitogenic effect of endotoxin was modest, however, and appeared to be unrelated to the ability of endotoxin to activate tissue factor. Inhibition of DNA synthesis in the cell cultures by cytosine arabinoside or nonlethal irradiation failed to impair the generation of tissue factor. Endotoxin contamination of various reagents used in cell culture was evaluated with the Limulus assay, which detected as little as 1 × 10-4μg/ml. of endotoxin. Endotoxin was detected in preparations of phytohemagglutinin, purified protein derivative of the tubercle bacillus, mumps vaccine, tetanus toxoid, concanavalin A, and pokeweed mitogen. Because of the broad implications of contamination by endotoxin of various reagents, we assessed the specificity of the Limulus assay for the detection of endotoxin in the lectin, concanavalin A, and determined that the reaction was specific for endotoxin. Contamination by endotoxin of mononuclear cell culture systems should be considered as a possible factor in the production of various biological effects attributed to some commonly used mitogens and antigens.

Original languageEnglish (US)
Pages (from-to)792-803
Number of pages12
JournalThe Journal of Laboratory and Clinical Medicine
Volume89
Issue number4
StatePublished - Apr 1977

ASJC Scopus subject areas

  • Pathology and Forensic Medicine

Fingerprint Dive into the research topics of 'Tissue factor generation by human mononuclear cells: Effects of endotoxin and dissociation of tissue factor generation from mitogenic response'. Together they form a unique fingerprint.

  • Cite this