Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2002-8-7
pubmed:abstractText
TCR down-modulation following binding to MHC/peptide complexes is considered to be instrumental for T cell activation because it allows serial triggering of receptors and the desensitization of stimulated cells. We studied CD3/TCR down-modulation and zeta degradation in T cells from two ZAP-70-immunodeficient patients. We show that, at high occupancy of the TCR, down-modulation of the CD3/TCR is comparable whether T cells express or do not express ZAP-70. However, if TCR occupancy was low, we found that CD3/TCR was down-regulated to a lesser extent in ZAP-70-negative than in ZAP-70-positive T cells. We studied CD3/TCR down-modulation in P116 (a ZAP-70-negative Jurkat cell-derived clone) and in P116 transfected with genes encoding the wild-type or a kinase-dead form of ZAP-70. Down-modulation of the TCR at high occupancy did not require ZAP-70, whereas at low TCR occupancy down-modulation was markedly reduced in the absence of ZAP-70 and in cells expressing a dead kinase mutant of ZAP-70. Thus, the presence of ZAP-70 alone is not sufficient for down-modulation; the kinase activity of this molecule is also required. The degradation of zeta induced by TCR triggering is also severely impaired in T cells from ZAP-70-deficient patients, P116 cells, and P116 cells expressing a kinase-dead form of ZAP-70. This defect in TCR-induced zeta degradation is observed at low and high levels of TCR occupancy. Our results identify ZAP-70, a tyrosine kinase known to be crucial for T cell activation, as a key player in TCR down-modulation and zeta degradation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
169
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1705-12
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
TCR/CD3 down-modulation and zeta degradation are regulated by ZAP-70.
pubmed:affiliation
Institut National de la Santé et de la Recherche Médicale, Unité 520, Institut Curie, Institut Pasteur, Paris, France.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't