Journal of Experimental Medicine, Vol 175, 1553-1563, Copyright © 1992 by Rockefeller University Press

ARTICLES

Functional analysis of the antigen binding site on the T cell receptor alpha chain

EA Nalefski, S Kasibhatla and A Rao
Division of Tumor Virology, Dana-Farber Cancer Institute, Boston, Massachusetts.

We have identified residues on a T cell receptor (TCR) alpha chain that are important for interaction with antigen/major histocompatibility complex (MHC). Using site-directed mutagenesis, we modified DNA encoding the postulated antigen/MHC binding loops on the TCR alpha chain expressed by the T cell clone D5, which recognizes p- azobenzenearsonate-conjugated antigens presented by cells bearing I-Ad. These variant TCR alpha chains were expressed in conjunction with the wild-type D5 TCR beta chain on the surface of hybridoma cells, and were tested for the ability to recognize hapten-conjugated antigens presented by I-Ad. Individual amino acid substitutions in each of the three antigen binding loops (alpha 1, alpha 2, alpha 3) of the D5 TCR alpha chain affected antigen recognition, demonstrating that all three loops are important in recognition of antigen/MHC. A subset of the single amino acid substitutions completely eliminated antigen recognition, thus identifying the residues that are particularly important in the recognition of antigenic peptide/MHC by the D5 TCR. Because the wild-type D5 TCR recognizes arsonate and certain structural analogues of arsonate conjugated to a variety of protein antigens, we were able to test whether the TCR substitutions affected the specificity of the D5 TCR for hapten or carrier antigen. One substitution introduced into antigen binding loop alpha 3 markedly altered the pattern of carrier recognition. Together, these results verify the Ig model for the TCR and are consistent with the proposition that residues forming the first and second antigen binding loops of the TCR contact the MHC, while those forming the third loop contact mainly antigenic peptides.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Facebook    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

• Brawley, J. V., Concannon, P. (2002). Complementarity-Determining Region 1 Sequence Requirements Drive Limited V{alpha} Usage in Response to Influenza Hemagglutinin 307-319 Peptide. J. Immunol. 168: 3894-3901 [Abstract] [Full Text]  
• Brawley, J. V., Concannon, P. (1999). Systematic Mutagenesis of TCR Complementarity-Determining Region 3 Residues: A Single Conservative Substitution Dramatically Improves Response to Both Multiple HLA-DR Alleles and Peptide Variants. J. Immunol. 163: 4946-4952 [Abstract] [Full Text]  
• Kessler, B., Michielin, O., Blanchard, C. L., Apostolou, I., Delarbre, C., Gachelin, G., Gregoire, C., Malissen, B., Cerottini, J.-C., Wurm, F., Karplus, M., Luescher, I. F. (1999). T Cell Recognition of Hapten. ANATOMY OF T CELL RECEPTOR BINDING OF A H-2Kd-ASSOCIATED PHOTOREACTIVE PEPTIDE DERIVATIVE. J. Biol. Chem. 274: 3622-3631 [Abstract] [Full Text]  
• Anjuere, F., Kuznetsov, D., Romero, P., Cerottini, J.-C., Jongeneel, C. V., Luescher, I. F. (1997). Differential Roles of T Cell Receptor alpha and beta Chains in Ligand Binding Among H-2Kd-restricted Cytolytic T Lymphocyte Clones Specific for a Photoreactive Plasmodium berghei Circumsporozoite Peptide Derivative. J. Biol. Chem. 272: 8505-8514 [Abstract] [Full Text]  
• Nalefski, E. A., Shaw, K. T. Y., Rao, A. (1995). An Ion Pair in Class II Major Histocompatibility Complex Heterodimers Critical for Surface Expression and Peptide Presentation. J. Biol. Chem. 270: 22351-22360 [Abstract] [Full Text]  

Home | Help | Feedback | Subscriptions | Archive | Search

TABLE OF CONTENTS