Antigen-Binding, Idiotypic T-Lymphocyte Receptors

Specific immune cognition and recognition are intrinsic capacities of mature, immunocompetent lymphocytes. B and T lymphocyte populations can both be shown to display this ability with high discriminatory power. At the single-cell level, however, both B and T lymphocytes express antigen-binding receptors with extreme restriction (Raff et al., 1973; Binz and Wigzell, 1975a). It would seem likely that in fact all receptors for antigen on a single B (Raff et al., 1973) or T (Binz and Wigzell, 1975a) lymphocyte express the same antigen-binding specificity. When T and B lymphocytes are compared with respect to their capacity to react against various epitopes, largely overlapping recognition spectra of antigenic specificities are found (Rajewsky and Mohr, 1974). Comparable mechanisms for the generation of diversity at the single-cell level of T and B cells would thus seem logical and economical. Whereas the biochemistry and underlying genetics of the B-cell receptors for antigen are by now relatively well understood, considerably less is known of the T-cell system.