On mechanisms of activation and restriction in T and B lymphocytes.

The mechanism of MHC restriction is discussed with special reference to cytotoxic T lymphocytes reactive against hapten-modified self determinants. Effector cell specificity is considered to reflect the specificity of primary induction and recognition between T lymphocytes and immunogenic antigenic determinants. Mechanisms of activation and development of different specificity repertoires in T and in B cells are discussed, with special reference to those self determinants that direct specificity and serve as markers for self-nonself discrimination.