STUDIES OF HYPERTHYMIC MICE .1. INFLUENCE OF MULTIPLE THYMUS GRAFTS ON SIZE OF PERIPHERAL T CELL POOL AND IMMUNOLOGICAL PERFORMANCE

Abstract

Following the implantation of syngeneic chromosomally marked thymuses under the kidney capsule of normal adult mice, donor T [thymus-derived] cells were found in the blood and other lymphoid organs. The mice had increased numbers of Thy.1-positive cells in spleen and lymph nodes, increased peripheral blood lymphocyte levels and also augmented immune responses to sheep erythrocytes. The contribution made by an individual graft to the donor T cell pool was independent of the number of thymuses grafted as was the growth of the grafts themselves. There is no homeostatic feedback control of thymus growth in adult mice.