Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
1996-12-31
pubmed:abstractText
CD73 is a glycosyl phosphatidylinositol (GPI)-anchored purine salvage enzyme (ecto-5'-nucleotidase (ecto-5'-NT), E.C. 3.1.3.5) whose expression on lymphocytes is dependent on their differentiation state and function. CD73 behaves as an agonistic molecule in signaling via the CD3/TCR and CD2 pathways and is associated with CTL generation, IgG production, and activation of resting naive CD8+ T cells. CD73 deficiency has been reported in a variety of patients with impaired T and/or B cell function. Thus, CD73 holds promise as a molecular target for intervention in the immune system, but the mechanisms regulating its expression are largely unknown. The aim of this study was to gain insight into the regulation of CD73 expression in human lymphocytes. CD38, another cell surface differentiation Ag with ecto-enzyme activities (NAD+ glycohydrolase, ADP-ribosyl cyclase, and cyclic ADP-ribose (cADPR) hydrolase), was found to specifically induce CD73 expression in T and B cell lines as well as in normal adult T and NK cells, cord blood T cells, and thymocytes. CD38 cross-linking induced a rapid export to the cell surface of pre-formed CD73 derived from an intracellular pool and not from de novo biosynthesis. This translocation was dependent on protein tyrosine kinase (PTK) activity and lasted approximately eight hours, after which CD73 was removed from the cell surface by enzymatic cleavage. CD73 was not induced by other agents that activate T cells and CD73 was the only GPI-anchored molecule up-regulated by CD38 ligation out of six analyzed. These results document a novel pathway in human lymphocytes leading from CD38 ligation to CD73 expression, which may result in the rapid acquisition of new functions, including increased purine salvage, increased sensitivity to Ag-induced activation, and the generation of adenosine (Ado) for Ado receptor signaling.
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
157
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4354-62
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Selective induction of CD73 expression in human lymphocytes by CD38 ligation: a novel pathway linking signal transducers with ecto-enzyme activities.
pubmed:affiliation
Division of Hematology of the University of Torino, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't