Studies on the termination of immunological tolerance in the mouse thymus cell population after irradiation.
Immunological tolerance in the mouse thymus cell population induced by the intravenous injection of deaggregated bovine gamma globulin was terminated by whole body irradiation. After irradiation, the weight of the thymus recovered biphasically, and the termination of tolerance occurred as early as in the first phase. Both Thy-1 antigen expression and helper activity of the thymus cell population in irradiated mice recovered in parallel with the recovery of the thymus weight. Sensitivity of the regenerating thymus cell to the tolerogen was not different from that of the normal thymus cell. The first phase of thymus regeneration may be caused by the proliferation and differentiation of relatively radioresistant and tolerogen insensitive precursors residing in the thymus. Tolerogen and/or immunogen reactive thymus cells may originate from the precursor.
D000818:Animals; D000954:Antigens, Surface; D005260:Female; D006854:Hydrocortisone / Q000494:pharmacology; D007108:Immune Tolerance / Q000528:radiation effects; D007700:Kinetics; D008565:Membrane Proteins; D051379:Mice; D008815:Mice, Inbred Strains; D009929:Organ Size; D013601:T-Lymphocytes / Q000276:immunology* / Q000528:radiation effects; D050378:T-Lymphocytes, Regulatory / Q000276:immunology; D018800:Thy-1 Antigens; D013950:Thymus Gland / Q000528:radiation effects
D000954:Antigens, Surface; D008565:Membrane Proteins; D018800:Thy-1 Antigens; D006854:Hydrocortisone