Bone marrow colony-forming cells in mice with virus-induced lymphoid leukemia: relation to serum colony-stimulating...

Mice with advanced lymphoid leukemia have elevated peripheral blood granulocytes and elevated serum colony-stimulating activity, which promotes the in vitro growth of granulocyte and/or macrophage colonies. The number of bone marrow precursor cells of the in vitro granulocyte and/or macrophage colonies varied from normal to 10% of normal. The elevation of colony-stimulating activity correlated best with a combination of increased blood granulocytes and a deficiency of bone marrow precursor cells, which suggested that colony-stimulating activity is a leukopoietin that increases the efficiency and rate of production of granulocytes.