Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
26
pubmed:dateCreated
1992-10-19
pubmed:abstractText
Exposure of T lymphocytes to phorbol esters induces endocytosis of CD4 and the CD3/T-cell receptor complex. We compared the pathway of CD4 internalization to that of CD3 following activation of human T lymphocytes with phorbol 12,13-dibutyrate (PDBu). Both CD3 and CD4 were rapidly internalized in response to PDBu, but only CD3, and not CD4, was recycled to the cell surface after removal of PDBu. In support of a degradative fate for internalized CD4, radioimmuno-precipitation studies revealed that the total amount of cellular CD4 was reduced by greater than 90% after exposure to PDBu for 4 h, whereas total CD3 remained constant. PDBu induced CD4 capping and localization consistent with sequestration in intracellular vesicles, presumably lysosomes, prior to becoming degraded. Lysosomotropic agents, such as NH4Cl, chloroquine, and monensin inhibited CD4 degradation, consistent with a lysosomal fate for CD4. Internalization and degradation of CD4 was blocked by staurosporine, an inhibitor of protein kinase C suggestive of a role for protein kinase C in the endocytic fate of CD4. The results of this study demonstrate that CD3 and CD4 follow distinct endocytic pathways which may be relevant to their having distinct roles in T cell activation and function.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
267
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
18837-43
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Degradation of CD4 following phorbol-induced internalization in human T lymphocytes. Evidence for distinct endocytic routing of CD4 and CD3.
pubmed:affiliation
Stanford Medical School Blood Center, Palo Alto, California 94304.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't