Persistence of Acquired Tolerance in Cells Transferred to an Antigen-Free Environment

Open Access
Publisher Website
Google Scholar
Abstract
Summary: Lymph node and spleen cells of rats tolerant to sheep erythrocytes were transplanted into isologous, lethally irradiated recipients. Growth of lymphoid cells in these animals, which were presumably free of antigen, did not result in termination of the tolerant state during a period of up to 6 weeks before initial challenge with antigen. Antibody response to another antigen was normal. The state of tolerance induced in the donor animals was not permanent as demonstrated by antibody production after 6 months in the tolerant donor controls. At this time, however, irradiated recipients of tolerant lymph node and spleen cells remained tolerant. The failure of lymphoid cells from spleen and lymph nodes to lose tolerance more rapidly in the absence of antigen suggests that other factors may be required for this change.