Source:http://linkedlifedata.com/resource/pubmed/id/11851891
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
1
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| pubmed:dateCreated |
2002-2-19
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| pubmed:abstractText |
Allergic contact dermatitis ensues from exaggerated T cell responses to haptens. Dendritic cells are required for the initiation of hapten sensitization, but they may not be necessary for disease expression. Here we investigated the antigen-presenting cell requirement of nickel-specific CD4+ lymphocytes isolated from the blood of six allergic individuals. A significant proportion (42 out of 121; 35%) of the T cell clones proliferated in vitro to nickel also in the absence of professional antigen-presenting cells, suggesting a direct T-T hapten presentation. Antigen-presenting-cell-independent T cells showed a predominant T helper 1 phenotype. Nickel recognition by these T cells was major histocompatibility complex class II restricted, not influenced by CD28 triggering, independent from their state of activation, and did not require processing. The capacity of this T cell subset to be directly stimulated by nickel was not due to unique antigen-presenting properties, as both antigen-presenting-cell-dependent and antigen-presenting-cell-independent clones displayed comparable levels of HLA-DR, CD80, and CD86, and were equally capable of presenting nickel to antigen-presenting-cell-independent clones. In contrast, neither T cell types activated antigen-presenting-cell-dependent T lymphocytes. T-T presentation induced T cell receptor downregulation, CD25, CD80, CD86, and HLA-DR upregulation, and interferon-gamma release, although to a lesser extent compared to those induced by dendritic cell-T presentation. Following T-T presentation, the clones did not undergo unresponsiveness and maintained the capacity to respond to dendritic cells pulsed with antigen. In aggregate, our data suggest that antigen-presenting-cell-independent T cell activation can effectively amplify hapten- specific immune responses.
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| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:citationSubset |
IM
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| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Antigens, CD,
http://linkedlifedata.com/resource/pubmed/chemical/Antigens, CD28,
http://linkedlifedata.com/resource/pubmed/chemical/Antigens, CD80,
http://linkedlifedata.com/resource/pubmed/chemical/Antigens, CD86,
http://linkedlifedata.com/resource/pubmed/chemical/CD86 protein, human,
http://linkedlifedata.com/resource/pubmed/chemical/Haptens,
http://linkedlifedata.com/resource/pubmed/chemical/Histocompatibility Antigens Class II,
http://linkedlifedata.com/resource/pubmed/chemical/Interferon-gamma,
http://linkedlifedata.com/resource/pubmed/chemical/Membrane Glycoproteins,
http://linkedlifedata.com/resource/pubmed/chemical/Nickel,
http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Antigen, T-Cell,
http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Interleukin-2
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| pubmed:status |
MEDLINE
|
| pubmed:month |
Jan
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| pubmed:issn |
0022-202X
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| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:volume |
118
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
172-9
|
| pubmed:dateRevised |
2008-11-21
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| pubmed:meshHeading |
pubmed-meshheading:11851891-Adult,
pubmed-meshheading:11851891-Antigen-Presenting Cells,
pubmed-meshheading:11851891-Antigens, CD,
pubmed-meshheading:11851891-Antigens, CD28,
pubmed-meshheading:11851891-Antigens, CD80,
pubmed-meshheading:11851891-Antigens, CD86,
pubmed-meshheading:11851891-CD4-Positive T-Lymphocytes,
pubmed-meshheading:11851891-Down-Regulation,
pubmed-meshheading:11851891-Female,
pubmed-meshheading:11851891-Haptens,
pubmed-meshheading:11851891-Histocompatibility Antigens Class II,
pubmed-meshheading:11851891-Humans,
pubmed-meshheading:11851891-Interferon-gamma,
pubmed-meshheading:11851891-Lymphocyte Activation,
pubmed-meshheading:11851891-Male,
pubmed-meshheading:11851891-Membrane Glycoproteins,
pubmed-meshheading:11851891-Nickel,
pubmed-meshheading:11851891-Receptors, Antigen, T-Cell,
pubmed-meshheading:11851891-Receptors, Interleukin-2,
pubmed-meshheading:11851891-Up-Regulation
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| pubmed:year |
2002
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| pubmed:articleTitle |
Activation of nickel-specific CD4+ T lymphocytes in the absence of professional antigen-presenting cells.
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| pubmed:affiliation |
Laboratory of Immunology and Department of Immunodermatology, Istituto Dermopatico dell' Immacolata, IRCCS, Rome, Italy.
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| pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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