Immunoregulation of contact sensitivity.

Contact sensitivity to dinitro-fluorobenzene in the mouse is a form of delayed-type hypersensitivity. This reaction is closely regulated. Tolerance to contact sensitivity is mediated by at least 2 mechanisms, tolerance without demonstrable suppressor cells and tolerance with suppressor T cells. Suppressor T cells can inhibit either the afferent limb of sensitization or the efferent (elicitation) phase. These cells probably operate via soluble suppressor factors and require auxiliary cells. The duration of contact sensitivity itself is controlled by another mechanism, which is antibody. This antibody is directed against the T cells responsible for the delayed hypersensitivity state (TDH), and down-regulate these cells. It is antigen-specific and has the properties of an antireceptor (anti-idiotypic) antibody.