Abstract
Recent studies using cloned antigen-specific T lymphocytes and monoclonal antibodies directed at their various surface glycoprotein components have led to the identification of the human T-cell antigen receptor as a surface complex comprised of a clonotypic 90-kD Ti heterodimer and the invariant 20- and 25-kD T3 molecules. Approximately 30,000-40,000 Ti and T3 molecules exist on the surface of human T lymphocytes. These glycoproteins are acquired and expressed during late thymic ontogeny, thus providing the structural basis for immunologic competence. The α and β subunits of Ti bear no precursor-product relationship to one another and are encoded by separate genes. Moreover, the presence of unique peptides following proteolysis of different Ti molecules isolated by non-cross-reactive anticlonotypic monoclonal antibodies supports the notion that variable regions exist within both the α and the β subunits. N-Terminal amino acid sequencing and molecular cloning of the Ti β subunit further show that it bears an homology to the first V-region framework of immunoglobulin light chains and represents the product of a gene that rearranges specifically in T lymphocytes. Triggering of the T3-Ti receptor complex gives rise to specific antigen-induced proliferation through an autocrine pathway involving endogenous IL-2 production, release, and subsequent binding to IL-2 receptors. The implications of these findings for understanding human T-cell growth and its regulation in disease states are discussed.
Original language | English |
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Pages (from-to) | 141-157 |
Number of pages | 17 |
Journal | Journal of Clinical Immunology |
Volume | 5 |
Issue number | 3 |
DOIs | |
Publication status | Published - May 1985 |
Keywords
- gene
- T cell antigen receptor
- T cell subset
ASJC Scopus subject areas
- Immunology and Allergy
- Immunology