Autosensitization of lymphocytes against thymus reticulum cells.

Lymph nodes of normal rats contain lymphocytes that can be induced in vitro to mediate a specific cellular immune reaction against reticulum cells derived from syngeneic adult thymus glands. It is likely that these lymphocytes had access to reticulum cell antigens during the period in which they developed immunocompetence within the thymus. This suggests that contact with self-antigens during development may not eliminate self-reactive lymphocytes. These findings are in conflict with the theory that natural tolerance to self-antigens depends upon elimination of lymphocyte clones.