| Abstract: | Serum from germfree Swiss/HaM mice exhibited a reduced capacity to stimulate granulocytic and mononuclear cell colony formation by DBA/1 bone marrow cells in vitro when compared with serum from conventional Swiss/HaM mice. Sera from germfree preleukemic and leukemic AKR mice exhibited strong colony stimulating activity, indicating that the increased colony stimulating activity previously observed in the serum of conventional leukemic mice is not the consequence of bacterial or fungal infections supervening in leukemic animals with deficient immune responses. |
