Functional specificity of thymus- dependent lymphocytes.

Thymus-dependent lymphocytes display a restricted range of specificity when compared to thymus-independent (B) lymphocytes. They react particularly to thymus-dependent protein and cell surface antigens and to products of genes encoded in the MHC. In addition, T lymphocytes have important functions in regulating the immune response and in discriminating of self from nonself. Recent work indicates that individual T lymphocytes possess receptors that interact with both thymus-dependent antigens and MHC gene products, either independently or as associated structures. We attempt to relate this complex specificity pattern to the regulatory and surveillance functions of T lymphocytes.