On the existence of suppressor cells

Immunological suppression is one of the important aspects which govern the regulation of the immune response. Clonal deletion, clonal anergy and the activity of suppressor cells were proposed as mechanisms leading to this phenomenon. In this review we provide evidence for the existence of suppressor (Ts) cells and their role in autoimmunity in general and particularly in the system of experimental allergic encephalomyelitis (EAE). Ts cell lines and clones that downregulate in-vivo the autoimmune response are described. These results, as well as other recent advances in the understanding of Ts cells regulatory mechanisms and the molecular structures recognized by these cells, lead to the conclusion that Ts cells do exist and that they constitute a distinctive cell type in regard to their function and specificity.