Cellular aspects of tolerance. I. Parameters of tolerance induction in T cells of spleen and thymus

Unresponsiveness of T cells in thymus and spleen of tolerant animals was determined by reconstitution of lethally irradiated recipients. The degree of responsiveness of these animals was assessed by antigen elimination and two types of plaque assays (liquid and agar) with different sensitivity. Unresponsiveness occurred more rapidly in T spleen cells than in thymus cells. Unresponsiveness of T cells could be induced in the spleens of thymectomized animals and in T cell repopulated thymectomized lethally irradiated recipients. Induction of unresponsiveness did not depend on proliferating bone marrow cells or on accessory cells.