T cell tolerance.

The population of T cells which bears ab receptors is thought to be central to a successful immune response, since it is abbearing cells which stimulate B cells, which give rise to cytotoxic T cells and which secrete many of the essential lymphokines. Self tolerance in this population is therefore absolutely necessary and may even be sufficient to prevent autoimmunity. It is for this reason than immunologists have long tried to understand how tolerance is induced in these cells.