Linked Life Data

3257504

Source:http://linkedlifedata.com/resource/pubmed/id/3257504

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1988-3-15
pubmed:abstractText
The T4 (CD4) molecule has been shown to facilitate the interactions of T cells with HLA class II determinants, to function as a signal transducing molecule, and to serve as a receptor for HIV. Recent studies demonstrated that both phorbol esters and antigen stimulation induced the rapid and transient modulation and phosphorylation of T4 on an IL-2-dependent line of cloned peripheral blood T4+ cells. In the current study, we define the kinetics of T4 phosphorylation and internalization induced by phorbol esters and determine the extent to which this metabolic pathway is required for T cell proliferation, activation, and HIV infection. On both peripheral blood T4+ cells and the T cell line Sup-T1, the modulation and internalization of surface T4 induced by phorbol 12, 13-dibutyrate (PDB) was preceded by rapid and transient phosphorylation. On both cell types, by 48 h, T4 was reexpressed on the cell surface in a nonphosphorylated form and was shown to be resistant to phosphorylation and internalization when these cells were reexposed to PDB. In contrast, T4 on the surface of PBL was neither phosphorylated nor down-modulated when PBL were stimulated by PHA, indicating that these effects were not simply the result of T cell activation or proliferation. In additional studies, we demonstrate that this pathway for T4 phosphorylation and internalization is not required for HIV infection by showing that 1) the binding of the HIV gp 120 envelope to T4 does not induce phosphorylation of T4, 2) Sup-T1 cells that are rendered resistant to phorbol ester-induced T4 internalization and phosphorylation by prolonged culture in PDB remain highly susceptible to HIV infection, and 3) clones of HIV-producing cells expressing high levels of surface T4 that is complexed with viral envelope remain susceptible to PDB-induced modulation of T4. This observation suggests that, at least on lymphoid cells, HIV penetration does not occur exclusively by R-mediated endocytosis.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
140
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
786-95
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
T4 endocytosis and phosphorylation induced by phorbol esters but not by mitogen or HIV infection.
pubmed:affiliation
Hematology-Oncology Section, Hospital of the University of Pennsylvania, Philadelphia 19104.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't