abstract
- The thymus of SJL/J mice of age 3-6 weeks has been previously shown to contain suppressor cells that inhibit the antibody response to lymph node cells to SRBC. The effect of these suppressor cells disappear as the animals age (24 weeks or more). We find that these aged animals acquire thymic suppressor cells which suppress the generation of cytotoxic T-cells both in vitro and in vivo. Although such suppressors are not present in the thymuses of young SJL/J mice, suppression can be induced by treatment with estrogen and progesterone. The differentiation of functionally different suppressor cell populations in thymus may be affected by both age and hormonal status.