Blood online
Home About Blood Authors Subscriptions Permission Advertising Public Access contact us
 

 
Advanced
Current Issue
First Edition
Archives
Submit to Blood
Search
American Society of Hematology
Meeting Abstracts
Email Alerts
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Right arrow Rights and Permissions
Citing Articles
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Miscia, S.
Right arrow Articles by Sabatino, G.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Miscia, S.
Right arrow Articles by Sabatino, G.
Related Collections
Right arrow Immunobiology
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?

arrow to previous article Previous Article  |  Table of Contents  |  Next Article next article arrow

Novel Evidence of Expression and Activity of Ecto-Phospholipase C gamma 1 in Human T Lymphocytes

Sebastiano Miscia, Angela Di Baldassarre, Amelia Cataldi, Rosa Alba Rana, Valerio Di Valerio, and Giuseppe Sabatino

From the Istituto di Morfologia Umana Normale and Cattedra di Neonatologia, Università G. D'Annunzio, Chieti, Italy.

Although much is known about the intracellular phospholipase C (PLC) specific for inositol phospholipids, few data are available about the presence of a less common PLC at the external side of the membrane bilayer of some cell types. This ectoenzyme seems to play particular roles in cellular function by hydrolyzing inositol lipids located on the outer leaflet of the plasma membrane. Here, we provide the first evidence that peripheral T lymphocytes express a discrete level of a PLCgamma 1 at the outer leaflet of the plasma membrane. Flow cytometry showed that the PLCgamma 1-positive (PLCgamma 1+) cells (~37%) were CD8+ and CD45RA+. Biochemical evidence indicated that (1) this ectoenzyme displays a mass similar to the cytoplasmic form, (2) it is phosphorylated on tyrosine residues, and (3) its activity is Ca2+-dependent. In addition, this enzyme appeared to be correlated with the proliferative state of the cell, since stimulation with phytohemagglutinin (PHA) downregulated both its expression and activity, which were restored by treatment with an antiproliferative agent like natural interferon beta. Moreover, the different kinetics of formation of its hydrolytic products, inositol 1 phosphate and inositol 1:2 cyclic phosphate (Ins(1)P and Ins(1:2 cycl)P), formed upon incubation of the lymphocytes with [3H]-lyso-phosphatidylinositol (PI), allow the hypothesis of a selective involvement of the two inositol phosphates in the mechanisms regulating the metabolism of particular T-lymphocyte subsets.

Blood, Vol. 91 No. 10 (May 15), 1998: pp. 3833-3840
© 1998 by The American Society of Hematology.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati    What's this?




click for free articles
home about blood authors subscriptions permissions advertising public access contact us
  Copyright © 1998 by American Society of Hematology         Online ISSN: 1528-0020