Feedback inhibition by human primed T-helper cells [13]

STUDIES in animal models, in particular that of the murine system, have revealed that the sequence of events leading to an antibody response is similar to other complex biological processes in that they are controlled by interrelated regulatory mechanisms^1,2. In man helper activity which regulates the antigen-induced antibody response in vitro is initiated by T lymphocytes bearing receptors for the Fc fragment of IgM (Tμ⁺ cells), whereas suppressive activity can be induced in T cells capable of binding the Fc fragment of IgG (Tγ⁺ cells)³. We present here data which indicate that Tμ⁺ cells, apart from providing help in the human antigen-driven process of B-cell activation, are also capable, in certain conditions, of inducing a subpopulation of unprimed T cells to suppress an antigen-induced antibody response.