Linked Life Data

10352273

Source:http://linkedlifedata.com/resource/pubmed/id/10352273

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
1999-6-16
pubmed:abstractText
The costimulatory molecule CD28 has a restricted tissue distribution and is expressed on T cells and some plasmacytoma cells. Although CD28 is constitutively expressed, its expression is transiently down-regulated following T cell activation and declines progressively with in vitro senescence. In vivo, CD8+ T cells and, less frequently, CD4+ T cells may completely lose CD28 surface expression during chronic infections and with aging. This correlates with changes of nuclear protein-binding activities to two motifs, site alpha and beta, within the CD28 minimal promoter. Both alpha- and beta-bound complexes are found only in lymphoid tissues, in CD28+ T cells, and in some transformed B cells. These complexes are coordinately expressed except during replicative senescence, which is characterized by the down-modulation of site beta- but not site alpha-binding activities. In contrast, T cell activation induces a parallel decline in both site alpha- and beta-binding activities. CD4+ and CD8+ T cells differ in their beta-binding profiles, which may explain the more pronounced down-regulation of CD28 in senescent CD8+ T cells. In vivo expanded CD4+CD28null and CD8+CD28null T cells uniformly lack alpha- and beta-bound complexes, resembling the pattern seen in chronically activated cells and not of senescent cells.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
162
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6572-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Modulation of CD28 expression: distinct regulatory pathways during activation and replicative senescence.
pubmed:affiliation
Division of Rheumatology, Department of Medicine, Mayo Clinic and Foundation, Rochester, MN 55905, USA. vallejo.abbe@mayo.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't