Regeneration of spleen colony-forming cells and granulocyte-monocyte progenitors in T-cell deprived mice treated with cyclophosphamide.

The role of T cells in regeneration of CFU-S(d8) and GM-CFU was investigated in adult Cy treated mice. CBA mice were deprived of T cells by adult thymectomy and irradiation (TIR) and treated with 200 mg/kg Cy. The type of CFU-S(d8) and GM-CFU regeneration curve after Cy was not different from that found in nonthymectomized, irradiated (NIR) mice. The activity of a stimulator of CFU-S(d8) proliferation was increased to the same degree in the bone marrow of both TIR and NIR mice. However CFU-S(d8) recovered to a higher level in TIR than in NIR mice. The results presented demonstrate that T-cell depletion in adult mice influences CFU-S(d8) growth.