Regulated expression of the human beta-globin gene after retroviral transfer into murine and human hematopoietic cells.

Retroviral vectors and infection protocols were developed which permit transfer in vitro of the human beta-globin gene into transformed erythroid cells and normal human and murine hematopoietic cells. In murine erythroleukemia (MEL) cells, RNA expression from the human beta-globin gene was regulated in parallel with the endogenous globin genes and this RNA directed synthesis of human beta-globin protein chains. Human BFU-E which were present in normal bone marrow samples were also infected with the globin virus. After erythroid maturation in vitro, several percent of the total beta-globin mRNA was derived from the virally transferred beta-globin gene in the erythroid progeny cells of the bursts. The initial design of the beta-globin vectors was improved after the removal of sequences which interfered with the production of high-titer retrovirus stocks. The improved vector can transfer the human beta-globin gene to pluripotential hematopoietic stem cells (PHSC) of the mouse as shown by long-term expression of human beta-globin RNA and protein in peripheral blood, and the presence of the globin provirus in reconstituted myeloid and lymphoid cell lineages in primary and secondary recipients of virus-infected bone marrow.