Linked Life Data

7594462

Source:http://linkedlifedata.com/resource/pubmed/id/7594462

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
1995-12-18
pubmed:abstractText
The expression of surface adenosine deaminase (ADA) and CD26 in activated human T cells was studied by flow cytometry. PBLs and CD3+ or CD4+ cells, when subjected to a variety of stimuli (anti-CD3 Abs plus IL-2 or phorbol esters), presented two structurally different cell populations, which differed in size and cellular complexity (populations B1 and B2). In PBLs triggered by an anti-CD3 mAb there was no significant increase of expression of either surface ADA or CD26 in cells of population B1, whose structure is similar to that of nonstimulated cells. In contrast, there was a significant increase in the percentage of expression of ADA and CD26 in the population B2, which corresponds to structurally more complex and larger cells. In the case of activation via TCR-CD3 but in the presence of IL-2 or via phorbol esters, the increase was found in cells from both populations, but B2 cells always showed a higher percentage of expression than B1 cells. The results of increased expression of surface ADA and CD26 were similar in whole T cells or in purer preparations such as CD3+ or CD4+ lymphocytes. Polyclonal Abs against ADA were not able to induce an activation response in T cells even when cross-linked by a secondary Ab. Interestingly, these Abs produced anergy in CD4+ cells subjected to an anti-CD3 stimulus. In contrast, addition of ADA produced an enzyme-independent synergism in the response through the TCR-CD3 complex. In T cells, ADA and CD26 colocalized on the surface of T cells; thus, the effect of exogenous ADA seems to be mediated by CD26 molecules that are not interacting with endogenous ADA (spare CD26 molecules). The presence of spare CD26 molecules on the surface of CD4+ cells was demonstrated by flow cytometry in the presence of exogenous ADA and also by confocal microscopy. The set of results strongly indicates that ADA binding to CD26 produces a costimulatory response in T cell activation events.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
155
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4630-43
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Expression of ecto-adenosine deaminase and CD26 in human T cells triggered by the TCR-CD3 complex. Possible role of adenosine deaminase as costimulatory molecule.
pubmed:affiliation
Department of Biochemistry and Molecular Biology, University of Barcelona, Catalonia, Spain.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't