Corticosterone treatment affects neonatal induction of immunological tolerance to hen egg lysozyme in mice

Immunological tolerance to hen egg lysozyme (HEL) was induced in mice by one injection of 0.1 mg of HEL intraperitoneally on day 0 (i.e. within the first 24 h after birth). After immunization with the same antigen 8 weeks later, such mice developed markedly lower numbers of specific antibody-forming cells than did the untreated controls. When the tolerized mice were injected with three doses (1 microgram each) of corticosterone (CN) on days 1, 3 and 5, the tolerogenic effect was markedly diminished. However, in adult animals neither the inducibility of tolerance nor the intensity of immune reaction was influenced by the early treatment with CN. No influence of early CN treatment on the in vitro response of spleen cells to T- and B-cell mitogens was found, when tested in adult animals. The results support a view that neonatally induced immunological tolerance to hen egg lysozyme is mediated by a population of antigen-specific regulatory cells, generation of which can be prevented by treatment with CN.