Linked Life Data

9894851

Source:http://linkedlifedata.com/resource/pubmed/id/9894851

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1999-4-13
pubmed:abstractText
Bacterial superantigens such as staphylococcal enterotoxin-A (SEA) have been implicated in the pathogenesis of psoriasis vulgaris. Major histocompatibility complex (MHC) class II molecules are high affinity receptors for SEA, and T cells found in psoriatic skin lesions express high levels of MHC class II. Here we address the question of whether SEA can directly activate psoriatic T cells in the absence of professional antigen-presenting cells. We show that SEA induces i) tyrosine phosphorylation of several proteins, ii) downregulation of the T-cell receptor (TCR), and iii) production of interferon-gamma (IFN-gamma), but not autocrine mitogenesis in CD8-positive T clones obtained from skin lesions of a patient with psoriasis vulgaris. Psoriatic T cells do not respond to SEA molecules if mutations are introduced in the TCRbeta- or in both the two MHC class II alpha- and beta-binding sites of SEA. Mutations in only one of the two MHC class II binding sites of SEA has different effects on T-cell activation. Thus, SEA molecules with a mutation in the MHC class II beta-binding site induce protein tyrosine phosphorylation, but not IFN-gamma production or co-stimulation of cytokine-mediated proliferation. In contrast, SEA with a mutation in the MHC class II alpha-binding site induces IFN-gamma and a qualitatively changed tyrosine phosphorylation profile. Both mutations delete the co-stimulatory effect on cytokine-mediated proliferation. This suggests that both MHC class II binding sites are involved in the autopresentation of SEA by psoriatic T cells. In conclusion, we provide evidence that SEA directly activates MVHC class H-positive psoriatic T-cell lines to produce IFN-gamma, a key cytokine in the pathogenesis of psoriasis vulgaris.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0001-2815
pubmed:author
pubmed:issnType
Print
pubmed:volume
52
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
530-8
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Staphylococcal enterotoxin-A directly stimulates signal transduction and interferon-gamma production in psoriatic T-cell lines.
pubmed:affiliation
Institute for Microbiology and Immunology, University of Copenhagen, Denmark.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't