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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
6
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pubmed:dateCreated |
1982-1-28
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pubmed:abstractText |
The environmental agents E. coli endotoxin and zymosan A modulated antigen-specific T cell proliferation in vitro, assessed by 3H-TdR uptake. In the continual presence of these agents, human mononuclear leukocyte responses to the antigens tuberculin PPD, Candida albicans, and mumps were significantly reduced. Treatment of adherent cell-depleted T cells with the agents did not affect their subsequent reactivity to soluble antigens in the presence of normal M phi. However, cultures consisting of pretreated M phi, normal T cells, and soluble antigen gave responses that were only 7 to 38% of control values, indicating that the function of the antigen-presenting cell, not the T cell, was inhibited. This effect was observed only when treatment with endotoxin or zymosan A preceded antigen stimulation by at least 24 hr, suggesting that a gradual inhibition of antigen presentation had occurred. When various ratios of normal antigen-pulsed and agent-treated M phi were cultured with normal T cells, antigen-specific responses were not significantly different from control cultures; this indicated that M phi-mediated suppression was not involved. It did not appear that the inhibition was due to enhanced antigen degradation by the treated M phi because responses were not reconstituted in the presence of excess antigen. After endotoxin or zymosan A treatment of the M phi population the proportion of Ia+ cells was reduced significantly, and surface expression of Ia antigen correlated with the ability of the cell population to present antigens to immune T cells. This suggested that endotoxin and zymosan A induce a loss of surface Ia antigen on antigen-presenting cells that inhibits immune T cell activation.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
AIM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Antigens,
http://linkedlifedata.com/resource/pubmed/chemical/Antigens, Surface,
http://linkedlifedata.com/resource/pubmed/chemical/Endotoxins,
http://linkedlifedata.com/resource/pubmed/chemical/Histocompatibility Antigens Class II,
http://linkedlifedata.com/resource/pubmed/chemical/Zymosan
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pubmed:status |
MEDLINE
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pubmed:month |
Dec
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pubmed:issn |
0022-1767
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
127
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
2245-51
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:6457870-Animals,
pubmed-meshheading:6457870-Antigens,
pubmed-meshheading:6457870-Antigens, Surface,
pubmed-meshheading:6457870-Endotoxins,
pubmed-meshheading:6457870-Histocompatibility Antigens Class II,
pubmed-meshheading:6457870-Humans,
pubmed-meshheading:6457870-Macrophage Activation,
pubmed-meshheading:6457870-Macrophages,
pubmed-meshheading:6457870-Mice,
pubmed-meshheading:6457870-Mice, Inbred Strains,
pubmed-meshheading:6457870-Monocytes,
pubmed-meshheading:6457870-Rabbits,
pubmed-meshheading:6457870-T-Lymphocytes, Regulatory,
pubmed-meshheading:6457870-Zymosan
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pubmed:year |
1981
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pubmed:articleTitle |
Modulation of Ia-like antigen expression and antigen-presenting activity of human monocytes by endotoxin and zymosan A.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
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