Cytokine production by mononuclear cells following stimulation with a peptide-containing, endotoxin-free Escherichia coli extract.
The beneficial effects of the E. coli extract Colibiogen inj. N (Cb) observed in therapy of inflammatory bowel diseases, allergies, or gastrointestinal tumors are possibly mediated by the induction of cytokines in human leukocytes or vascular cells. Thus, the induction of the cytokines interleukin 1 (IL1), IL6 and tumor necrosis factor (TNF) in human mononuclear cells (MNC) and vascular cells was investigated in vitro. Various administration forms of the extract (including Cb-inj. N, Cb-oral, and Cb-infantibus N) induced the release of IL1 and IL6 from MNC. The compounds stimulated TNF production less potently, possibly due to a lower sensitivity of the TNF assay system, as compared to the IL1 and IL6 detection system. The MNC produced the cytokines with a kinetics similar to that observed with other stimuli. Monospecific antibodies abolished the respective cytokine activity in the biological assays. Addition of submaximal amounts of endotoxin potently enhanced the IL1- and IL6-inducing activity of the bacterial extract, indicating synergism of the extract and endotoxin. These results provide evidence that cytokines produced by MNC following administration of the tested bacterial extract may contribute to the regulation of the immune response during therapy of gastrointestinal tumors. At present the in vivo production of cytokines following treatment with the bacterial extract tested is under investigation in a phase III study.
Thomsen
A
A
Borstel Research Institute, Department of Immunology and Cell Biology, Germany.
Loppnow
H
H
D016207:Cytokines / Q000096:biosynthesis*; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D007375:Interleukin-1 / Q000096:biosynthesis; D015850:Interleukin-6 / Q000096:biosynthesis; D008070:Lipopolysaccharides / Q000494:pharmacology; D009000:Monocytes / Q000378:metabolism*; D010455:Peptides / Q000494:pharmacology*; D013268:Stimulation, Chemical; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
D016207:Cytokines; D007375:Interleukin-1; D015850:Interleukin-6; D008070:Lipopolysaccharides; D010455:Peptides; D014409:Tumor Necrosis Factor-alpha; C047752:colibiogen