Stable Lentiviral Vector Transfer into Mesenchymal Stem Cells In Vivo.

Green fluorescent protein (eGFP) gene was transferred into mouse mesenchymal stem cells in vivo using a lentiviral vector. In 2 months after injection of the lentivirus into the cavity of the femoral bone, up to 30% fibroblast CFU in the bone marrow of infected mice contained the alien gene. The transferred gene was found in more than 50% of adherent layers of longterm bone marrow cultures formed by mesenchymal stem cells from the infected mice bone marrow; 4% fibroblast CFU obtained from these layers were labeled.

Peculiarities of Gene Transfer into Mesenchymal Stem Cells.

Murine mesenchymal stem cells in long-term bone marrow culture were genetically labeled using lentiviral vector carrying enhanced green fluorescent protein (eGFP) reporter gene under SFFV promoter or without it. We studied the developmental fate of labeled mesenchymal stem cells in stromal cell layers of long-term bone marrow culture and in ectopic hemopoietic foci formed by these stromal layers under the renal capsule of syngeneic mice. The frequency of labeled polypotent stromal precursors (fibroblast CFU) was analyzed in adherent cell layers of long-term culture and ectopic foci formed from them.

Characteristics of leukemia stem cells of murine myeloproliferative disease involving the liver.

We studied surface phenotype of tumor cells and characterized leukemia stem cells in various cell populations with phenotypes of stem and committed precursor cells in the hierarchy of hemopoietic stem cells. Transplantable murine leukemia was used as the model. Bone marrow and liver cells from mice in the terminal phase of the disease were stained with antibodies to various surface markers and analyzed on a flow cytofuorometer.