Abnormal T-lymphocyte proliferation and cytotoxic responses induced by a neonatal injection of hydrocortisone:...

Spleen cells from mice neonatally treated with hydrocortisone hemisuccinate (HHC) had an abnormal pattern of cell-mediated immunity when tested two weeks later. Mitogen-induced proliferation was reduced. The proliferative responses to allo-antigens were normal but the cytotoxic response thereby induced was impaired. The mechanisms of these anomalies are complex: reduction of cytotoxic precursors as measured by limiting dilution assays; enhancement of suppressor cells which are able to reduce the cytotoxic response of normal spleen cells; reduction of interleukin-2 (Il-2) production. The addition of exogenous Il-2 restores normal proliferative and cytotoxic responses.