Reduced competitive repopulation capacity of multipotential hematopoietic stem cells in the bone marrow of friend virus-infected Fv2-resistant mice

Background/Aim: The polycythemia form of Friend leukemia virus (FVP) causes splenomegaly and lethal erythroleukemia in Fv-2s-susceptible mouse strains. We sought to determine whether the hematopoietic stem cell (HSC) pool was expanded in Fv-2^r-resistant mice. Materials and Methods: The 120-day bone marrow transplantation competitive repopulation assay was used to determine whether FVP-infected Fv-2^r C57BL/6 mice demonstrated expansion of the HSC pool compared to the pool of committed hematopoietic progenitor cells in the same marrow assayed in vitro. Results: There was a significant expansion of committed hematopoietic progenitors observed in virus-infected Fv-2s FVB mice, but not Fv-2^r C57BL/6 mice. Furthermore, Fv-2^r mice showed no detectable expansion of either committed hematopoietic progenitor cells or the multipotential stem cell pool by competitive repopulation assay. Conclusion: Friend virus disease in Fv-2s mice is associated with expansion of committed hematopoietic progenitors. Fv-2^r mice show no expansion of either committed progenitor or pluripotential stem cell numbers.