Source:http://linkedlifedata.com/resource/pubmed/id/10477697
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
5
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pubmed:dateCreated |
1999-9-29
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pubmed:abstractText |
Interleukin-12 (IL-12) is a potent proinflammatory and immunoregulatory cytokine skewing T lymphocytes to express a type 1 cytokine pattern. Optimal expression of IL-12 mRNA and bioactivity in vitro requires specific priming of monocytes by interferon-gamma (IFN-gamma) or granulocyte-macrophage colony-stimulating factor (GM-CSF) before lipopolysaccharide (LPS) stimulation. We show here for the first time that the production of IL-12 by IFN-gamma- or GM-CSF-primed human monocytes can be completely suppressed by preincubation with LPS (from Escherichia coli Serotype 055:B5) for 6 to 24 hours before the priming procedure. A dose-dependent suppression of IL-12p70 was measured on the levels of intracellular cytokine production and cytokine secretion. mRNA studies on the expression of p40 and p35 showed an LPS-induced downregulation of both subunits. The results of several different experimental approaches suggest that IL-12 downregulation was not due to endogenous IL-10, IL-4, prostaglandin E(2) (PGE(2)), tumor necrosis factor-alpha (TNF-alpha), or nitric oxide (NO) production induced by LPS. Moreover, preincubation of monocytes with LPS did not lead to a downregulation of the CD14 antigen, which is an LPS receptor. LPS preincubation in this experimental setting did not result in a general hyporesponsiveness of the monocytes, as IL-6 production as well as IFN-gamma-induced upregulation of CD54 did not decline. Downregulation of IL-12 was not due to changes in mRNA stability. These findings show that the immunoregulatory important cytokine, IL-12, underlies itself a complex regulation.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
AIM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Antiviral Agents,
http://linkedlifedata.com/resource/pubmed/chemical/Granulocyte-Macrophage...,
http://linkedlifedata.com/resource/pubmed/chemical/Interferon-gamma,
http://linkedlifedata.com/resource/pubmed/chemical/Interleukin-12,
http://linkedlifedata.com/resource/pubmed/chemical/Lipopolysaccharides,
http://linkedlifedata.com/resource/pubmed/chemical/RNA, Messenger
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pubmed:status |
MEDLINE
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pubmed:month |
Sep
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pubmed:issn |
0006-4971
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
1
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pubmed:volume |
94
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
1717-26
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pubmed:dateRevised |
2008-11-21
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pubmed:meshHeading |
pubmed-meshheading:10477697-Antiviral Agents,
pubmed-meshheading:10477697-Cells, Cultured,
pubmed-meshheading:10477697-Down-Regulation,
pubmed-meshheading:10477697-Flow Cytometry,
pubmed-meshheading:10477697-Granulocyte-Macrophage Colony-Stimulating Factor,
pubmed-meshheading:10477697-Humans,
pubmed-meshheading:10477697-Interferon-gamma,
pubmed-meshheading:10477697-Interleukin-12,
pubmed-meshheading:10477697-Lipopolysaccharides,
pubmed-meshheading:10477697-Monocytes,
pubmed-meshheading:10477697-RNA, Messenger
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pubmed:year |
1999
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pubmed:articleTitle |
Suppression of interleukin-12 production by human monocytes after preincubation with lipopolysaccharide.
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pubmed:affiliation |
Hannover Medical University, Department of Dermatology and Allergology, Hannover, Germany.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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