Effect of iodoacetate on the bone marrow immunocompetence of AKR mice.

Studies were conducted to determine whether the sulfhydryl inhibitor, sodium iodoacetate, administered to preleukemic AKR mice and to mature C3H mice altered the immunocompetence of their bone marrow. Parameters investigated included the splenic plaque-forming capacity directed to sheep erythrocytes of bone marrow transferred from iodoacetate-treated aanimals to irradiated syngeneic recipients and the mitogenic responsiveness of bone marrow cells from untreated and iodoacetate-treated preleukemic AKR mice to phytohemagglutinin and concanavalin A. The administration of two 0.5-ml doses of 10 mM iodoacetate to preleukemic AKR mice and to C3H mice resulted in a significant increase in bone marrow immunocompetence. Irradiated mice given marrow transplants from iodoacetate-treated syngeneic donors exhibited greater numbers of plaque-forming cells directed against sheep erythrocytes than did recipients of marrow from control animals. This effect was abrogated when the donor marrow was previously treated in vitro with rabbit antimouse brain serum and the complement to remove thymus-derived lymphocytes. The mitogenic responsiveness of marrow cultures from iodoacetate-treated AKR mice to phytohemagglutinin was similar to that observed for control mice, while the response to concanavalin A was decreased. These findings suggest that the administration of iodoacetate potentiated the immunocompetence of bone marrow by affecting thymus-derived cells.