Studies on the proliferation of thymus cells injected into syngeneic or alogeneic irradiated mice

Thymus cells from normal isologous or allogeneic animals were injected intravenously into lethally irradiated mice. With the aid of a particle size analyser it was observed that blast cells appeared in the spleens of mice injected with allogeneic thymus cells. By means of specific alloantisera against the infused cells or host, it was established that these cells were derived from the injected cells. Evidence is presented indicating that the blast transformed cells were derived from a specific population of cortisone resistant thymic cells.