Detection of specific antigen-sensitized T-lymphocytes in human tonsils

Tonsillar lymphocytes from children immunized against rubella were cultured with various mitogens, including phytohemagglutinin and rubella virus. Sheep red cells were subsequently added to detect rosette-forming T-lymphocytes, and the suspension tested by autoradiography to identify transformed cells. With PHA, 60--80% of the cells were transformed, of which 37% were rosette-forming T-cells. With rubella antigen only 31% of lymphocytes were transformed, but almost all of these formed rosettes. It is concluded that PHA stimulates B- as well as T-cells alone; such stimulation may therefore be a more reliable test of T-cell function and of cell-mediated immunity.