Induction and separation of antigen-dependent T helper and T suppressor cells in man

Abstract

INDUCTION of plaque-forming cells (PFC), specific for sheep red blood cells (SRBC) or ovalbumin (OA), from human peripheral blood requires the cooperation of surface IgM-positive B cells and E-rosette-forming T lymphocytes^1,2. At high antigen concentrations PFC responses are suppressed² and it seemed that this effect might be mediated in part by antigen-stimulated T lymphocytes^2,3. We have studied the functional activity of purified T cells which had been preincubated (‘primed’) for 24 h in the presence of a high concentration of antigen. We report here that such primed cell preparations contain antigen-specific suppressor cells which interfere with the induction of PFC in autologous target PFC cultures. These suppressor cells and their precursors could be isolated in the theophylline-sensitive lymphocyte fraction⁴.