Title
Zeta Phosphorylation without ZAP-70 Activation Induced by TCR Antagonists or Partial Agonists
Document Type
Article
Publication Date
1-27-1995
Journal
Science
Volume
267
Issue
5197
First Page
515
Last Page
518
URL with Digital Object Identifier
http://dx.doi.org/10.1126/science.7824949
Abstract
Small changes in the peptide-major histocompatibility complex (MHC) molecule ligands recognized by antigen-specific T cell receptors (TCRs) can convert fully activating complexes into partially activating or even inhibitory ones. This study examined early TCR-dependent signals induced by such partial agonists or antagonists. In contrast to typical agonist ligands, both an antagonist and several partial agonists stimulated a distinct pattern of zeta chain phosphorylation and failed to activate associated ZAP-70 kinase. These results identify a specific step in the early tyrosine phosphorylation cascade that is altered after TCR engagement with modified peptide-MHC molecule complexes. This finding may explain the different biological responses to TCR occupancy by these variant ligands.
Notes
Dr. Joaquin Madrenas is currently a faculty member at The University of Western Ontario.