Induction of interleukin-1-beta release from human monocytes by cotton bract tannin.
The human T lymphocyte proliferative response to cotton bract tannin was shown to be dependent upon the presence of monocytes. Since monocytes support the T cell mitogenic response by interleukin-1 (IL-1) production, it was anticipated that tannin has IL-1-inducing ability. To examine this possibility, human monocytes were cultured alone or with peripheral blood T lymphocytes, and stimulated with tannin. Control cultures included unstimulated cells, and cells challenged with other IL-1 inducers: concanavalin A (Con A) and lipopolysaccharide from Escherichia coli or Enterobacter agglomerans. IL-1 beta was measured in culture supernatants 24 h after initiation of the culture by the use of an ELISA or an RIA. The results showed that tannin stimulated monocytes to secrete IL-1 beta in a manner similar to Con A, i.e. substantially more cytokine was measured in the supernatants of monocyte-T-lymphocyte co-cultures than in the cultures of monocyte alone. Endotoxin from E. coli was less effective than the endotoxin from E. agglomerans in IL-1 induction. Contaminating endotoxin present in the tannin preparation accounted for the majority of IL-1 beta released from monocytes alone stimulated with tannin, but only 20% of the IL-1 beta released from tannin-stimulated monocyte-T-lymphocyte co-cultures. These results show that tannin itself has IL-1-inducing ability. The dose-response studies show that the extent of IL-1 beta release is dependent on tannin dose and that increased levels of monocyte-produced IL-1 beta precede the increase in T lymphocyte proliferation.(ABSTRACT TRUNCATED AT 250 WORDS)
Thoracic Diseases Research Unit, Mayo Clinic, Rochester, Minn.
Z
Z
Vuk-Pavlović
M S
MS
Rohrbach
D002478:Cells, Cultured; D003208:Concanavalin A; D004754:Enterobacter / Q000276:immunology; D004926:Escherichia coli / Q000276:immunology; D003368:Gossypium / Q000276:immunology; D006801:Humans; D007375:Interleukin-1 / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000276:immunology; D008213:Lymphocyte Activation / Q000187:drug effects; D009000:Monocytes / Q000187:drug effects* / Q000378:metabolism; D037121:Plant Lectins; D013601:T-Lymphocytes / Q000187:drug effects; D013634:Tannins / Q000276:immunology*
D007375:Interleukin-1; D008070:Lipopolysaccharides; D037121:Plant Lectins; D013634:Tannins; D003208:Concanavalin A