Cells expressing human glucocerebrosidase from a retroviral vector repopulate macrophages and central nervous system microglia after murine bone marrow transplantation

Abstract

Gaucher disease is an inherited lysosomal storage disease in which the loss in functional activity of glucocerebrosidase (GC) results in the storage of its lipid substrate in cells of the macrophage lineage. A gene therapy approach involving retroviral transduction of autologous bone marrow (BM) followed by transplantation has been recently approved for clinical trial. Amelioration of the disease symptoms may depend on the replacement of diseased macrophages with incoming cells expressing human GC; however, the processes of donor cell engraftment and vector gene expression have not been addressed at the cellular level in relevant tissues. Therefore, we undertook a comprehensive immunohistologic study of macrophage and microglia replacement after murine BM transplantation with retrovirus-marked BM. Serial quantitative PCR analyses were employed to provide an overview of the time course of engraftment of vector-marked cells in a panel of tissues. Following reconstitution of hematopoietic tissues with vector- marked donor cells at early stages, GC+ cells began to infiltrate the liver, lung, brain, and spinal cord by 3 months after transplant. Immunohistochemical analyses of PCR+ tissues using the 8E4 monoclonal antibody specific for human GC revealed that macrophages expressing human GC had partially reconstituted the Mac-1+ population in all tissues in a manner characteristic to each tissue type. In the brain, 20% of the total microglia had been replaced with donor cells expressing GC by 3 to 4 months after transplant. The finding that significant numbers of donor cells expressing a retroviral gene product immigrate to the central nervous system suggests that gene therapy for neuronopathic forms of lysosomal storage diseases as well as antiviral gene therapy for AIDS may be feasible.

Hematopoietic Stem Cell Transplantation and Hematopoietic Stem Cell Gene Therapy in X‐Linked Adrenoleukodystrophy

“…Transplantation of autologous HSCs genetically modified to express the missing protein may circumvent the majority of the problems associated with allogeneic HSCT. In 1994, transplantation of murine bone marrow cells, which had been transduced with a murine retroviral vector that expressed the glucocerebrosidase gene (which is deficient in Gaucher's disease), resulted in the replacement of 20% of microglia with donor-derived microglia that expressed the glucocerebrosidase gene for 3 months to 4 months after transplantation (25). In 2001, an human immunodeficiency virus type 1 (HIV-1)-derived lentivirus vector was used to transduce ex vivo murine bone marrow cells, which were reinjected into irradiated mice (44); this study demonstrated that bone marrow-derived microglia that expressed the green fluorescent protein reporter gene was specifically attracted to sites of neuronal damage.…”

Neural Stem Cells as Engraftable Packaging Lines Can Mediate Gene Delivery to Microglia: Evidence from Studying Retroviral env -Related Neurodegeneration

“…netic, sporadic, and infectious diseases (7,12,17,35) and have been rather refractory to genetic manipulation due to their limited turnover in the mature CNS (24,26,27). Observations in the OB (a region of persistent postnatal neurogenesis where env expression extended beyond donor cell engraftment and colocalized with neuronal and glial markers) suggest that dividing cells of neuroectodermal origin may also be targeted (Fig.…”

“…Prior transgenic approaches to achieve either global or cell-type-specific CNS CasBrE env expression have been unsuccessful in approximating the expression associated with CNS viral infection (22, 31a, 62). Furthermore, attempts to genetically manipulate the microglial compartment by using bone marrow chimeras have been hampered because of a very slow turnover of parenchymal microglial cells (20,24,26). Virus-based vectors offer a potential alternative for manipulating the microglial compartment since they have been demonstrated to be effective vehicles for the in vivo transfer of exogenous genes directly to endogenous cells in the CNS (58).…”

The Different Forms of Mucopolysaccharidosis with Neurological Involvement: A Case-Based Review

“…Since then, there have been 500 MPS children who underwent BMT, most of whom were affected by MPS-I-H. 8,9 HSCT has the potential to ameliorate CNS-related deficits, [10][11][12] since, following infusion of bone marrow-derived cells from a matched donor, monocytes that circulate in the blood can engraft the CNS behaving as perivascular or meningeal macrophages. [13][14][15] HSCT is typically recommended for patients with MPS-I-H younger than 2 years with normal cognition (intelligence quotient > 70) due to the fact that early intervention increases the likelihood of maintaining cognitive abilities. 12 Unfortunately, early diagnosis (and hence early initiation of treatment) is limited by several factors, including the infrequency of the disease, the wide variability in clinical presentation and disease course, and the nonspecific nature of some of the early manifestations of the disease.…”