Radiosensitivity of T and B lymphocytes. V. Effects of whole-body irradiation on numbers of recirculating T cells and sensitization to primary skin grafts in mice.
Whole-body exposure of mice to 50, 100, 300, or 500 rads results in an acute dose-related decrease in the number of viable recirculating T cells. The magnitude of this decrement becomes more pronounced with the passage of time. The dose-response relationship over this range of dosages appears to consist of three components: a steep drop between 0 and 50 rads, a plateau between 50 and 500 rads, and a second drop between 300 and 500 rads. The residual radioresistant cells are able to recognize a histoincompatible skin graft during the initial 5 days after irradiation. Low to moderate doses (50 to 300 rads) abrogate the partial tolerance noted in nonirradiated recipients exposed to the skin graft for 5 days and then regrafted from the same donor source 25 days after complete removal of the primary graft. A large (500 rads) dose results in prolonged graft survival in comparison with the nonirradiated group. It is suggested that the subpopulation fo recirculating T cells which develops partial tolerance during a 5-day exposure to a homograft is more radiosensitive than the effector subpopulation which is involved in graft rejection.
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006084:Graft Rejection / Q000528:radiation effects*; D006648:Histocompatibility; D008297:Male; D051379:Mice; D008808:Mice, Inbred CBA; D011836:Radiation Tolerance; D016038:Skin Transplantation; D013601:T-Lymphocytes / Q000276:immunology / Q000528:radiation effects*; D013897:Thoracic Duct / Q000166:cytology; D014184:Transplantation, Homologous; D014965:X-Rays