Restricted V-(D)-J junctional regions in the T cell response to lambda-repressor. Identification of residues critical for antigen recognition.
The T cell response to lambda-repressor is directed to a 15 amino acid peptide (P12-26) of the protein in A/J mice. Previous studies have demonstrated a preferential use of V alpha 2 and V beta 1 amongst the T cell hybridomas specific for P12-26 in the context of I-Ek. By using the polymerase chain reaction, the sequences of a panel of the T cells using V alpha 2 and V beta 1 were determined. A highly conserved alpha-chain V-J junctional sequence was found in six of the eight T cell hybrids. This consensus alpha-chain VJ sequence may be combined with different members of V alpha 2, indicating a more restricted selection on the junctional region than on the V element in these T cells. In contrast, greater diversities were found on the V-D-J region of beta-chains despite the same V beta 1 and J beta 2.1 were used. However, a highly conserved glutamic acid residue was found at the same position of beta-chains where a similar conservation was identified in cytochrome c-specific T cells. The correlation of the TCR sequence with the fine specificities of these T cells suggests that a single amino acid deletion in the V alpha-J alpha region may reduce the P12-26 response and abolish the recognition of an altered peptide [Phe22] P12-26. In addition, three amino acid difference in the V-D-J region of the beta-chain also determine the P12-26 reactivity. Thus the V(D)J junctional regions of both alpha- and beta-chains may be critical for the recognition of the peptide Ag presented by the specific MHC molecule.
Lai
M Z
MZ
Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan, R.O.C.
Jang
Y J
YJ
Chen
L K
LK
Gefter
M L
ML
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004268:DNA-Binding Proteins; D004306:Dose-Response Relationship, Immunologic; D000939:Epitopes; D015332:Gene Rearrangement, alpha-Chain T-Cell Antigen Receptor; D015333:Gene Rearrangement, beta-Chain T-Cell Antigen Receptor; D051379:Mice; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011948:Receptors, Antigen, T-Cell / Q000235:genetics / Q000276:immunology*; D012097:Repressor Proteins / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D014157:Transcription Factors / Q000276:immunology*; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins
D004268:DNA-Binding Proteins; D000939:Epitopes; D011948:Receptors, Antigen, T-Cell; D012097:Repressor Proteins; D014157:Transcription Factors; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins; C016649:phage repressor proteins