Demonstration of suppressor T cells in a population of ‘educated’ T cells

Abstract

THE regulation of the immune response, in the sense of the limitation of its extent, can probably be achieved in two main ways. The first, and more extensively studied, is the feedback effect of the antibody end-product, brought about either by the removal of antigen, or by the blockage of antigen recognition by antigen-sensitive cells¹. A second possibility suggested more recently is that certain regulatory cells exist which can exert an actively suppressive influence on immune responses². Since they are believed to be among the thymus-derived or T cell population, they may be termed suppressor T cells. Evidence for their existence includes the enhancement of certain responses by anti-lymphocyte serum^3–5, the suppressive influence of graft-versus-host reactions^6,7, and recent observations on antigenic competition^8,9, infectious tolerance¹⁰, and allotype suppression¹¹.