Linked Life Data

7734424

Source:http://linkedlifedata.com/resource/pubmed/id/7734424

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1995-6-7
pubmed:abstractText
Staphylococcus enterotoxins bind class II MHC molecules on antigen presenting cells (APC) and stimulate T cells expressing appropriate V beta gene products. Although the role of non-TCR associated co-stimulatory receptors during antigen-specific T cell stimulation has been clearly established, the involvement of co-stimulatory activity in T cell activation by superantigens has been the matter of controversy. In this report, we examine the role of co-stimulation provided by selected APC populations in the response to bacterial exotoxins (staphylococcal enterotoxin A, staphylococcal enterotoxin B and toxic shock syndrome type 1). We demonstrate that the APC population able to activate naive T cells to IL-2 production is heterogeneous, comprising both adherent (presumably dendritic) and non-adherent (mostly B lymphocytes) cells. By stimulating naive T cells in the presence of graded doses of superantigens, we have observed that half-maximal IL-2 production was achieved at lower doses of superantigens in the presence of dendritic cells. Similarly, addition of antibodies to CD28 or B7.1-transfected cell lines increased the sensitivity of naive T cells to lower doses of superantigens. These observations indicate therefore that superantigens can be presented to naive T cells by APC displaying distinct levels of co-stimulatory activity, although with different efficacy. Thus, naive T cells are sensitive to CD28-mediated co-stimulation during superantigen-mediated responses but IL-2 production can be induced by high doses of superantigens in the presence of APC expressing weak co-stimulatory activity. These observations are compatible with the hypothesis that CD28-mediated signals participate in T cell activation by lowering T cell sensitivity to TCR ligands.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0953-8178
pubmed:author
pubmed:issnType
Print
pubmed:volume
7
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
295-304
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Co-stimulation lowers the threshold for activation of naive T cells by bacterial superantigens.
pubmed:affiliation
Département de Biologie Moléculaire, Université Libre de Bruxelles, Rhode-St-Genèse, Belgium.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't