Selection of variable-joining region combinations in the alpha chain of the T cell receptor.
Most T lymphocytes express an antigen-specific receptor composed of two subunits, alpha and beta, each of which can exhibit structural variability. A complex selection process operates on T cells during development in the thymus such that cells expressing only particular alpha beta-receptors migrate to the periphery. The alpha-chain repertoire was dissected at different stages of the selection process by using the polymerase chain reaction (PCR) technique to amplify only those transcripts of a particular variable region gene (V58). Sequences from these V58 cDNAs reveal the predominant expression of four joining (J) segments by T cells in the adult thymus, suggesting that molecular or cellular processes select particular V alpha J alpha combinations during development. T cells expressing one of these V58J alpha chains appear to have been negatively selected at a later stage, since these transcripts were present in the spleen at approximately one-tenth the level in the thymus. Results also indicate that residues present at the V alpha J alpha junction may be important in an early selection process.
Roth
M E
ME
Department of Biochemistry, University of Illinois, Urbana 61801.
Lacy
M J
MJ
McNeil
L K
LK
Kranz
D M
DM
D000818:Animals; D001483:Base Sequence; D005796:Genes; D008285:Major Histocompatibility Complex; D051379:Mice; D008815:Mice, Inbred Strains; D008969:Molecular Sequence Data; D011948:Receptors, Antigen, T-Cell / Q000235:genetics*; D016693:Receptors, Antigen, T-Cell, alpha-beta; D011995:Recombination, Genetic; D013154:Spleen / Q000502:physiology; D013601:T-Lymphocytes / Q000502:physiology*; D013950:Thymus Gland / Q000502:physiology; D014018:Tissue Distribution
D011948:Receptors, Antigen, T-Cell; D016693:Receptors, Antigen, T-Cell, alpha-beta