Influence of Thymus Cells on Erythropoiesis of Parental Marrow in Irradiated Hybrid Mice ∗

Abstract

Summary

Living parental thymus cells injected into heavily irradiated F₁ hybrid recipients augmented erythropoiesis resulting from transplanted bone marrow from the same, but not the second, parental strain. The augmentation increased as parental thymus cell dose was increased. Thymus cells alone, regardless of origin, gave rise to no erythropoiesis. When recipient spleen weight, 8 days after marrow transplantation, was used as a criterion of marrow growth, the data for parental cell doses 4 × 10⁷ and above paralleled those from ⁵⁹Fe-uptake studies in the same mice. Parental thymus cells were effective even when administered 1 to 2 days before or after the marrow transplant.