Efficient transfer and sustained high expression of the human glucocerebrosidase gene in mice and their functional macrophages following transplantation of bone marrow transduced by a retroviral vector

A recombinant retroviral vector (MFG-GC) was used to study the efficiency of transduction of the human gene encoding glucocerebrosidase (GC; D-glucosyl-N-acylsphingosine glucohydrolase, EC 3.2.1.45), in mouse hematopoietic stem cells and expression in their progeny. Transfer of the GC gene to CFU-S (spleen cell colony-forming units) in primary and secondary recipients was virtually 100%. In mice 4-7 months after transplantation, highly efficient transfer of the human gene to bone marrow cells capable of long-term reconstitution was confirmed by detection of one or two copies per mouse genome in hematopoietic tissues and in cultures of pure macrophages. Expression of the human gene exceeded endogenous activity by several fold in primary and secondary CFU-S, tissues from long-term reconstituted mice, and explanted macrophage cultures. These studies are evidence of the feasibility of efficient transfer of the GC gene to hematopoietic stem cells and expression in their progeny for many months after reconstitution. The results of this study strengthen the rationale for gene therapy as a treatment for Gaucher disease.