scholarly journals Altered Peptide Ligands Induce Delayed CD8-T Cell Receptor Interaction—a Role for CD8 in Distinguishing Antigen Quality

Immunity ◽  
2006 ◽  
Vol 25 (2) ◽  
pp. 203-211 ◽  
Author(s):  
Pia P. Yachi ◽  
Jeanette Ampudia ◽  
Tomasz Zal ◽  
Nicholas R.J. Gascoigne
1996 ◽  
Vol 184 (4) ◽  
pp. 1259-1268 ◽  
Author(s):  
G J Kersh ◽  
P M Allen

T cells recognize short linear peptides bound to major histocompatibility complex (MHC)-encoded molecules. Subtle molecular changes in peptide antigens produce altered peptide ligands (APLs), which induce different T cell responses from those induced by the antigenic ligand. A molecular basis for how these slight molecular variations lead to such different consequences for the T cell has not been described. To address this issue, we have made amino acid substitutions at the primary T cell receptor (TCR) contact residue of the murine hemoglobin determinant, Hb(64-76)/I-Ek and produced 12 peptides that interact with the TCR of the T cell clone 3.L2. The 3.L2 T cell responds to these peptides, which vary 1 million-fold in their activity, and enables them to be ranked according to their relative ability to signal through the 3.L2 TCR. Such a ranking reveals that the ability of the 3.L2 T cell to respond to these peptides depends on how well the structure of the side chain at the primary TCR contact site mimics that of the Asn residue present in the antigenic ligand. The reactivity of the 3.L2 T cell also depends on an MHC contact residue that is next to the primary TCR contact residue, suggesting that conformation of the Asn side chain is also important. By using nonnatural amino acids at a TCR contact residue, we have demonstrated that APLs can be rationally designed based on structure. These data are consistent with a model in which the affinity of a peptide-MHC complex for the TCR determines how the T cell will respond.


2010 ◽  
Vol 47 (9) ◽  
pp. 1793-1801 ◽  
Author(s):  
Stephen P. Persaud ◽  
David L. Donermeyer ◽  
K. Scott Weber ◽  
David M. Kranz ◽  
Paul M. Allen

2018 ◽  
Vol 26 (4) ◽  
pp. 996-1007 ◽  
Author(s):  
Timothy T. Spear ◽  
Yuan Wang ◽  
Thomas W. Smith ◽  
Patricia E. Simms ◽  
Elizabeth Garrett-Mayer ◽  
...  

2005 ◽  
Vol 6 (8) ◽  
pp. 785-792 ◽  
Author(s):  
Pia P Yachi ◽  
Jeanette Ampudia ◽  
Nicholas R J Gascoigne ◽  
Tomasz Zal

2001 ◽  
Vol 193 (3) ◽  
pp. 329-338 ◽  
Author(s):  
George S. Vratsanos ◽  
Sungsoo Jung ◽  
Yeong-Min Park ◽  
Joe Craft

Polyclonal CD4+ T cell activation is characteristic of spontaneous lupus. As a potential explanation for this phenotype, we hypothesized that T cells from lupus-prone mice are intrinsically hyperresponsive to stimulation with antigen, particularly to those peptide ligands having a low affinity for the T cell receptor (TCR). To test this hypothesis, we backcrossed the α and β chain genes of the AND TCR specific for amino acids 88–104 of pigeon cytochrome C (PCC) to the Fas-intact MRL/Mp+Fas-lpr and to the H-2k–matched control backgrounds B10.BR and CBA/CaJ (MRL.AND, B10.AND, and CBA.AND, respectively), and assessed naive CD4+ TCR transgenic T cell activation in vitro after its encounter with cognate antigen and lower affinity altered peptide ligands (APLs). MRL.AND T cells, compared with control B10.AND and CBA.AND cells, proliferated more when stimulated with agonist antigen. More strikingly, MRL.AND T cells proliferated significantly more and produced more interleukin 2 when stimulated with the APLs of PCC 88–104, having lower affinity for the transgenic TCR. These results imply that one of the forces driving polyclonal activation of α/β T cells in lupus is an intrinsically heightened response to peptide antigen, particularly those with low affinity for the TCR, independent of the nature of the antigen-presenting cell and degree of costimulation.


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